US20080024489A1 - Cache Utilization Optimized Ray Traversal Algorithm with Minimized Memory Bandwidth Requirements - Google Patents
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- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T15/00—3D [Three Dimensional] image rendering
- G06T15/06—Ray-tracing
Definitions
- Embodiments of the invention generally relate to the field of image processing.
- image processing The process of rendering two-dimensional images from three-dimensional scenes is commonly referred to as image processing.
- image processing evolves as well.
- One particular goal in the evolution of image processing is to make two-dimensional simulations or renditions of three-dimensional scenes as realistic as possible.
- One limitation of rendering realistic images is that modern monitors display images through the use of pixels.
- a pixel is the smallest area of space which can be illuminated on a monitor. Most modern computer monitors will use a combination of hundreds of thousands or millions of pixels to compose the entire display or rendered scene.
- the individual pixels are arranged in a grid pattern and collectively cover the entire viewing area of the monitor. Each individual pixel may be illuminated to render a final picture for viewing.
- Rasterization is the process of taking a two-dimensional image represented in vector format (mathematical representations of geometric objects within a scene) and converting the image into individual pixels for display on the monitor. Rasterization is effective at rendering graphics quickly and using relatively low amounts of computational power; however, rasterization suffers from some drawbacks. For example, rasterization often suffers from a lack of realism because it is not based on the physical properties of light, rather rasterization is based on the shape of three-dimensional geometric objects in a scene projected onto a two dimensional plane.
- ray tracing Another technique for rendering a real world three-dimensional scene onto a two-dimensional monitor using pixels is called ray tracing.
- the ray tracing technique traces the propagation of imaginary rays, rays which behave similar to rays of light, into a three-dimensional scene which is to be rendered onto a computer screen.
- the rays originate from the eye(s) of a viewer sitting behind the computer screen and traverse through pixels, which make up the computer screen, towards the three-dimensional scene.
- Each traced ray proceeds into the scene and may intersect with objects within the scene. If a ray intersects an object within the scene, properties of the object and several other contributing factors are used to calculate the amount of color and light, or lack thereof, the ray is exposed to. These calculations are then used to determine the final color of the pixel through which the traced ray passed.
- the process of tracing rays is carried out many times for a single scene. For example, a single ray may be traced for each pixel in the display. Once a sufficient number of rays have been traced to determine the color of all of the pixels which make up the two-dimensional display of the computer screen, the two dimensional synthesis of the three-dimensional scene can be displayed on the computer screen to the viewer.
- Ray tracing typically renders real world three dimensional scenes with more realism than rasterization. This is partially due to the fact that ray tracing simulates how light travels and behaves in a real world environment, rather than simply projecting a three dimensional shape onto a two dimensional plane as is done with rasterization. Therefore, graphics rendered using ray tracing more accurately depict on a monitor what our eyes are accustomed to seeing in the real world.
- ray tracing also handles increases in scene complexity better than rasterization as scenes become more complex. Ray tracing scales logarithmically with scene complexity. This is due to the fact that the same number of rays may be cast into a scene, even if the scene becomes more complex. Therefore, ray tracing does not suffer in terms of computational power requirements as scenes become more complex as rasterization does.
- Embodiments of the present invention generally provide methods and apparatus for performing ray tracing.
- a method of ray tracing utilizing a spatial index having nodes defining bounded volumes of a three dimensional scene comprising: generating a ray into the scene; traversing the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; recording a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determining if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traversing the spatial index using the recorded traversal history.
- a computer readable medium containing a program which, when executed, performs an operation for ray tracing utilizing a spatial index having nodes defining bounded volumes of a three dimensional scene is provided.
- the operation generally comprising: generating a ray into the scene; traversing the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; recording a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determining if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traversing the spatial index using the recorded traversal history.
- a system comprising a spatial index having nodes defining bounded volumes of a three dimensional scene; and a first processing element, wherein the first processing element is generally configured to: generate a ray into the scene; traverse the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; record a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determine if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traverse the spatial index using the recorded traversal history.
- FIG. 1 illustrates a multiple core processing element, according to one embodiment of the invention.
- FIG. 2 illustrates multiple core processing element network, according to one embodiment of the invention.
- FIG. 3 is an exemplary three dimensional scene to be rendered by an image processing system, according to one embodiment of the invention.
- FIGS. 4A-4C illustrate a two dimensional space to be rendered by an image processing system and a corresponding spatial index created by an image processing system, according to one embodiment of the invention.
- FIG. 5 illustrates a spatial index and a corresponding data structure for storing traversal history of a ray through the spatial index, according to one embodiment of the invention.
- FIGS. 6 and 7 are flowcharts illustrating methods for traversing a spatial index, according to one embodiment of the invention.
- FIG. 8 is an exemplary two dimensional space to be rendered by an image processing system, according to one embodiment of the invention.
- FIGS. 9A-9G illustrate the traversal of a ray through a spatial index, according to one embodiment of the invention.
- Embodiments of the invention provide techniques and systems for recording the traversal history of a ray through a spatial index structure and utilizing the recorded traversal history of a ray through the spatial index.
- An image processing system may initially determine which nodes a ray intersects as it traverses through a spatial index. Results of the node intersection determinations may be recorded as the ray traverses the spatial index, and the recorded determinations may be associated with the ray. Furthermore, the image processing system may decide upon a traversal path based upon some probability of striking primitives corresponding to the nodes which make up the spatial index. This traversal path may also be recorded and associated with the ray. If the image processing system needs to re-traverse the spatial index at a later time, the recorded traversal history may be used to eliminate the need to recalculate ray-node intersections, and eliminate incorrect traversal path determinations.
- FIG. 1 illustrates a multiple core processing element 100 , according to one embodiment of the invention.
- the multiple core processing element 100 includes a plurality of basic throughput engines 105 (BTEs).
- BTE 105 may contain a plurality of processing threads and a core cache (e.g., an L1 cache).
- the processing threads located within each BTE may have access to a shared multiple core processing element cache 110 (e.g., an L2 cache).
- the BTEs 105 may also have access to a plurality of inboxes 115 .
- the inboxes 115 may be memory mapped address space.
- the inboxes 115 may be mapped to the processing threads located within each of the BTEs 105 .
- Each thread located within the BTEs may have a memory mapped inbox and access to all of the other memory mapped inboxes 115 .
- the inboxes 115 make up a low latency and high bandwidth communications network used by the BTEs 105 .
- the BTEs may use the inboxes 115 as a network to communicate with each other and redistribute data processing work amongst the BTEs.
- separate outboxes may be used in the communications network, for example, to receive the results of processing by BTEs 105 .
- inboxes 115 may also serve as outboxes, for example, with one BTE 105 writing the results of a processing function directly to the inbox of another BTE 105 that will use the results.
- the aggregate performance of an image processing system may be tied to how well the BTEs can partition and redistribute work.
- the network of inboxes 115 may be used to collect and distribute work to other BTEs without corrupting the shared multiple core processing element cache 110 with BTE communication data packets that have no frame to frame coherency.
- An image processing system which can render many millions of triangles per frame may include many BTEs 105 connected in this manner.
- the threads of one BTE 105 may be assigned to a workload manager.
- An image processing system may use various software and hardware components to render a two dimensional image from a three dimensional scene.
- an image processing system may use a workload manager to traverse a spatial index with a ray issued by the image processing system.
- a spatial index as described further below with regards to FIG. 4 , may be implemented as a tree type data structure used to partition a relatively large three dimensional scene into smaller bounding volumes.
- An image processing system using a ray tracing methodology for image processing may use a spatial index to quickly determine ray-bounding volume intersections.
- the workload manager may perform ray-bounding volume intersection tests by using the spatial index.
- other threads of the multiple core processing element BTEs 105 on the multiple core processing element 100 may be vector throughput engines.
- the workload manager may issue (send), via the inboxes 115 , the ray to one of a plurality of vector throughput engines.
- the vector throughput engines may then determine if the ray intersects a primitive contained within the bounding volume.
- the vector throughput engines may also perform operations relating to determining the color of the pixel through which the ray passed.
- FIG. 2 illustrates a network of multiple core processing elements 200 , according to one embodiment of the invention.
- FIG. 2 also illustrates one embodiment of the invention where the threads of one of the BTEs of the multiple core processing element 100 is a workload manager 205 .
- Each multiple core processing element 220 1-N in the network of multiple core processing elements 200 may contain one workload manager 205 1-N , according to one embodiment of the invention.
- Each processor 220 in the network of multiple core processing elements 200 may also contain a plurality of vector throughput engines 210 , according to one embodiment of the invention.
- the workload managers 220 1-N may use a high speed bus 225 to communicate with other workload managers 220 1-N and/or vector throughput engines 210 of other multiple core processing elements 220 , according to one embodiment of the invention.
- Each of the vector throughput engines 210 may use the high speed bus 225 to communicate with other vector throughput engines 210 or the workload managers 205 .
- the workload manager processors 205 may use the high speed bus 225 to collect and distribute image processing related tasks to other workload manager processors 205 , and/or distribute tasks to other vector throughput engines 210 .
- the use of a high speed bus 225 may allow the workload managers 205 1-N to communicate without affecting the caches 230 with data packets related to workload manager 205 communications.
- FIG. 3 is an exemplary three dimensional scene 305 to be rendered by an image processing system.
- the objects 320 in FIG. 3 are of different geometric shapes. Although only four objects 320 are illustrated in FIG. 3 , the number of objects in a typical three dimensional scene may be more or less. Commonly, three dimensional scenes will have many more objects than illustrated in FIG. 3 .
- the objects are of varying geometric shape and size.
- one object in FIG. 3 is a pyramid 320 A .
- Other objects in FIG. 3 are boxes 320 B-D .
- objects are often broken up into smaller geometric shapes (e.g., squares, circles, triangles, etc.). The larger objects are then represented by a number of the smaller simple geometric shapes. These smaller geometric shapes are often referred to as primitives.
- the light sources may illuminate the objects 320 located within the scene 305 . Furthermore, depending on the location of the light sources 325 and the objects 320 within the scene 305 , the light sources may cause shadows to be cast onto objects within the scene 305 .
- the three dimensional scene 305 may be rendered into a two-dimensional picture by an image processing system.
- the image processing system may also cause the two-dimensional picture to be displayed on a monitor 310 .
- the monitor 310 may use many pixels 330 of different colors to render the final two-dimensional picture.
- Ray tracing is accomplished by the image processing system “issuing” or “shooting” rays from the perspective of a viewer 315 into the three-dimensional scene 320 .
- the rays have properties and behavior similar to light rays.
- FIG. 3 One ray 340 , that originates at the position of the viewer 315 and traverses through the three-dimensional scene 305 , can be seen in FIG. 3 .
- the ray 340 traverses from the viewer 315 to the three-dimensional scene 305 , the ray 340 passes through a plane where the final two-dimensional picture will be rendered by the image processing system. In FIG. 3 this plane is represented by the monitor 310 .
- the point the ray 340 passes through the plane, or monitor 310 is represented by a pixel 335 .
- the number of rays issued per pixel may vary. Some pixels may have many rays issued for a particular scene to be rendered. In which case the final color of the pixel is determined by the each color contribution from all of the rays that were issued for the pixel. Other pixels may only have a single ray issued to determine the resulting color of the pixel in the two-dimensional picture. Some pixels may not have any rays issued by the image processing system, in which case their color may be determined, approximated or assigned by algorithms within the image processing system.
- the image processing system To determine the final color of the pixel 335 in the two dimensional picture, the image processing system must determine if the ray 340 intersects an object within the scene. If the ray does not intersect an object within the scene it may be assigned a default background color (e.g., blue or black, representing the day or night sky). Conversely, as the ray 340 traverses through the three dimensional scene the ray 340 may strike objects. As the rays strike objects within the scene the color of the object may be assigned the pixel through which the ray passes. However, the color of the object must be determined before it is assigned to the pixel.
- a default background color e.g., blue or black, representing the day or night sky
- the color of the object struck by the original ray 340 may contribute to many factors. For example, light sources within the three dimensional scene may illuminate the object. Furthermore, physical properties of the object may contribute to the color of the object. For example, if the object is reflective or transparent, other non-light source objects may then contribute to the color of the object.
- secondary rays may be issued from the point where the original ray 340 intersected the object.
- one type of secondary ray may be a shadow ray.
- a shadow ray may be used to determine the contribution of light to the point where the original ray 340 intersected the object.
- Another type of secondary ray may be a transmitted ray.
- a transmitted ray may be used to determine what color or light may be transmitted through the body of the object.
- a third type of secondary ray may be a reflected ray.
- a reflected ray may be used to determine what color or light is reflected onto the object.
- one type of secondary ray may be a shadow ray.
- Each shadow ray may be traced from the point of intersection of the original ray and the object, to a light source within the three-dimensional scene 305 . If the ray reaches the light source without encountering another object before the ray reaches the light source, then the light source will illuminate the object struck by the original ray at the point where the original ray struck the object.
- shadow ray 341 A may be issued from the point where original ray 340 intersected the object 320 A , and may traverse in a direction towards the light source 325 A .
- the shadow ray 341 A reaches the light source 325 A without encountering any other objects 320 within the scene 305 . Therefore, the light source 325 A will illuminate the object 320 A at the point where the original ray 340 intersected the object 320 A .
- Shadow rays may have their path between the point where the original ray struck the object and the light source blocked by another object within the three-dimensional scene. If the object obstructing the path between the point on the object the original ray struck and the light source is opaque, then the light source will not illuminate the object at the point where the original ray struck the object. Thus, the light source may not contribute to the color of the original ray and consequently neither to the color of the pixel to be rendered in the two-dimensional picture. However, if the object is translucent or transparent, then the light source may illuminate the object at the point where the original ray struck the object.
- shadow ray 341 B may be issued from the point where the original ray 340 intersected with the object 320 A , and may traverse in a direction towards the light source 325 B .
- the path of the shadow ray 341 B is blocked by an object 320 D .
- the object 320 D is opaque, then the light source 325 B will not illuminate the object 320 A at the point where the original ray 340 intersected the object 320 A .
- the object 320 D which the shadow ray is translucent or transparent the light source 325 B may illuminate the object 320 A at the point where the original ray 340 intersected the object 320 A .
- a transmitted ray may be issued by the image processing system if the object with which the original ray intersected has transparent or translucent properties (e.g., glass).
- a transmitted ray traverses through the object at an angle relative to the angle at which the original ray struck the object. For example, transmitted ray 344 is seen traversing through the object 320 A which the original ray 340 intersected.
- Another type of secondary ray is a reflected ray. If the object with which the original ray intersected has reflective properties (e.g. a metal finish), then a reflected ray will be issued by the image processing system to determine what color or light may be reflected by the object. Reflected rays traverse away from the object at an angle relative to the angle at which the original ray intersected the object. For example, reflected ray 343 may be issued by the image processing system to determine what color or light may be reflected by the object 320 A which the original ray 340 intersected.
- reflective properties e.g. a metal finish
- a spatial index divides a three-dimensional scene or world into smaller volumes (smaller relative to the entire three-dimensional scene) which may or may not contain primitives.
- An image processing system can then use the known boundaries of these smaller volumes to determine if a ray may intersect primitives contained within the smaller volumes. If a ray does intersect a volume containing primitives, then a ray intersection test can be run using the trajectory of the ray against the known location and dimensions of the primitives contained within that volume.
- a spatial index greatly increases the performance of a ray tracing image processing system.
- Some examples of different spatial index acceleration data structures are octrees, k dimensional Trees (kd-Trees), and binary space partitioning trees (BSP trees).
- a kd-Tree uses axis aligned bounding volumes to partition the entire scene or space into smaller volumes. That is, the kd-Tree may divide a three dimensional space encompassed by a scene through the use of splitting planes which are parallel to known axes. The splitting planes partition a larger space into smaller bounding volumes. Together the smaller bounding volumes make up the entire space in the scene. The determination to partition (divide) a larger bounding volume into two smaller bounding volumes may be made by the image processing system through the use of a kd-tree construction algorithm.
- One criterion for determining when to partition a bounding volume into smaller volumes may be the number of primitives contained within the bounding volume. That is, as long as a bounding volume contains more primitives than a predetermined threshold, the tree construction algorithm may continue to divide volumes by drawing more splitting planes. Another criterion for determining when to partition a bounding volume into smaller volumes may be the amount of space contained within the bounding volume. Furthermore, a decision to continue partitioning the bounding volume may also be based on how many primitives may be intersected by the plane which creates the bounding volume.
- the partitioning of the scene may be represented by a binary tree structure made up of nodes, branches and leaves.
- Each internal node within the tree may represent a relatively large bounding volume, while the node may contain branches to sub-nodes which may represent two relatively smaller partitioned volumes resulting after a partitioning of the relatively large bounding volume by a splitting plane.
- each internal node may contain only two branches to other nodes.
- the internal node may contain branches (i.e., pointers) to one or two leaf nodes.
- a leaf node is a node which is not further sub-divided into smaller volumes and contains pointers to primitives.
- An internal node may also contain branches to other internal nodes which are further sub-divided.
- An internal node may also contain the information needed to determine along what axis the splitting plane was drawn and where along the axis the splitting plane was drawn.
- FIGS. 4A-4C illustrate a two dimensional space to be rendered by an image processing system and a corresponding kd-tree.
- a two dimensional scene is used to illustrate the building of a kd-Tree, however kd-Trees may also be used to represent three dimensional scenes.
- splitting lines are illustrated instead of splitting planes, and bounding areas are illustrated instead of bounding volumes as would be used in a three dimensional structure.
- bounding areas are illustrated instead of bounding volumes as would be used in a three dimensional structure.
- the concepts may easily be applied to a three dimensional scene containing objects.
- FIG. 4A illustrates a two dimensional scene 405 containing primitives 410 to be rendered in the final picture to be displayed on a monitor 310 .
- the largest volume which represents the entire volume of the scene is encompassed by bounding volume 1 (BV 1 ).
- this may be represented by the top level node 450 , also known as the root or world node.
- an image processing system may continue to partition bounding volumes into smaller bounding volumes when the bounding volume contains, for example, more than two primitives.
- the decision to continue partitioning a bounding volume into smaller bounding volumes may be based on many factors, however for ease of explanation in this example the decision to continue partitioning a bounding volume is based only on the number of primitives. As can be seen in FIG. 4A , BV 1 contains six primitives, therefore kd-Tree construction algorithm may partition BV 1 into smaller bounding volumes.
- FIG. 4B illustrates the same two dimensional scene 405 as illustrated in FIG. 4A .
- the tree construction algorithm has partitioned BV 1 into two smaller bounding volumes BV 2 and BV 3 .
- the partitioning of BV 1 was accomplished, by drawing a splitting plane SP 1 415 along the x-axis at point x 1 .
- This partitioning of BV 1 is also reflected in the kd-Tree as the two nodes 455 and 460 , corresponding to BV 2 and BV 3 respectively, under the internal or parent node BV 1 450 .
- the internal node representing BV 1 may now store information such as, but not limited to, pointers to the two nodes beneath BV 1 (e.g., BV 2 and BV 3 ), along which axis the splitting plane was drawn (e.g., x-axis), and where along the axis the splitting plane was drawn (e.g., at point x 1 ).
- the kd-Tree construction algorithm may continue to partition bounding volume BV 3 because it contains more than the predetermined threshold of primitives (e.g., more than two primitives). However, the kd-Tree construction algorithm may not continue to partition bounding volume BV 2 , because bounding volume BV 2 contains less than or equal to the number of primitives (e.g., only two primitives 410 A ). Nodes which are not partitioned or sub-divided any further, such as BV 2 , are referred to as leaf nodes.
- FIG. 4C illustrates the same two dimensional scene 405 as illustrated in FIG. 4B .
- the kd-Tree construction algorithm has partitioned BV 3 into two smaller bounding volumes BV 4 and BV 5 .
- the kd-construction algorithm has partitioned BV 3 using a partitioning plane along the y-axis at point y 1 . Since BV 3 has been partitioned into two sub-nodes it may now be referred to as an internal node.
- the partitioning of BV 3 is also reflected in the kd-Tree as the two leaf nodes 465 and 470 , corresponding to BV 4 and BV 5 respectively.
- BV 4 and BV 5 are leaf nodes because the volumes they represent are not further divided into smaller bounding volumes.
- the two leaf nodes, BV 4 and BV 5 are located under the internal node BV 3 which represents the bounding volume which was partitioned in the kd-Tree.
- the internal node representing BV 3 may store information such as, but not limited to, pointers to the two leaf nodes (i.e., BV 4 and BV 5 ), along which axis the splitting plane was drawn (i.e., y-axis), and where along the axis the splitting plane was drawn (i.e., at point y 1 ).
- the kd-Tree construction algorithm may now stop partitioning the bounding volumes because all bounding volumes located within the scene contain less than or equal to the maximum predetermined number of primitives which may be enclosed within a bounding volume.
- the leaf nodes may contain pointers to the primitives which are enclosed within the bounding volumes each leaf represents. For example, leaf node BV 2 may contain pointers to primitives 410 A , leaf node BV 4 may contain pointers to primitives 410 B, and leaf node BV 5 may contain pointers to primitives 410 C .
- a ray tracing image processing system may use the workload manager 205 to traverse the spatial index (kd-Tree). Traversing the kd-Tree may include selecting a branch to a node on a lower level (sub-node) of the kd-Tree to take or proceed to in order to determine if the ray intersects any primitives contained within the sub-node.
- a workload manager 205 may use the coordinates and trajectory of an issued ray to traverse or navigate through the kd-Tree. By executing ray-bounding volume intersection tests, the workload manager 205 may determine if the ray intersects a plane of the bounding volumes represented by nodes within the kd-Tree structure.
- the workload manager 205 may send the ray and associated information to a vector throughput engine 210 for ray-primitive intersection tests.
- a ray-primitive intersection test may be executed to determine if the ray intersects the primitives within the bounding volume. This methodology results in fewer ray-primitive intersection tests needed to determine if a ray intersects an object within the scene, in comparison to running ray-primitive intersection tests for a ray against each primitive contained within the scene.
- the resulting kd-Tree structure may be stored in a processor cache 230 .
- the kd-Tree and the size of corresponding data which comprises the kd-Tree may be optimized for storage in a processor cache 230 .
- the storage of the kd-Tree in a processor cache 230 may allow a workload manager 205 to traverse the kd-Tree with a ray that has been issued by the image processing system without having to retrieve the kd-Tree from memory every time a ray is issued by the image processing system.
- a node history may be stored for each level of internal node depth within the spatial index (e.g., kd-Tree).
- the node level history may be used to store information relating to bounding volume-ray intersection tests and kd-Tree traversal. By saving the results of previous tests and kd-Tree traversal the image processing system may take advantage of prior test results to reduce the amount processing necessary to determine a ray-primitive intersection.
- node history bits for each level may be stored in a nibble of a node history data structure sent along with (e.g., appended to) the information which describes the ray.
- FIG. 5 illustrates an exemplary kd-Tree 550 and a corresponding exemplary node history data structure 545 , according to one embodiment of the invention.
- the exemplary kd-Tree 550 is illustrated as containing eight levels of internal node depth (L 1 -L 8 ).
- the corresponding node history 545 may contain the same number of nibbles as the kd-Tree 550 contains internal node levels (L 1 -L 8 ). Therefore, according to one embodiment of the invention, the node history 545 may contain eight nibbles (i.e., 32 bits) which may record the history of ray-intersection tests and kd-Tree traversal.
- the most significant nibble L 1 may correspond to the first level L 1 (i.e., the root or world node) within the kd-Tree 550 and the least significant nibble L 8 may correspond to the lowest level L 8 within the kd-tree 550 .
- Each nibble within the node history data structure 545 may contain four bits.
- the two most significant bits 525 of each nibble may correspond to a node located to the left and below an internal node.
- the two least significant bits 530 of each nibble may relate to a node located to the right and below an internal node.
- the most significant bit 505 of each nibble may be set (e.g., to a high state, or a “1”) if the ray-bounding volume intersection test was executed and the ray intersected the bounding volume represented by the node to the left and below an internal node.
- the second most significant bit 505 may be set if the workload manager 205 “took” the branch or traversed to the node, located to the left and below the internal node, while traversing the kd-tree.
- a path is considered “taken” if the kd-tree was traversed to reach an internal or leaf node along the path.
- the third most significant bit 515 may be set if the ray-bounding volume intersection test was executed and the ray intersected the bounding volume represented by the node located to the right and below the internal node.
- the least significant bit 520 may be set if the workload manager 205 “took” the branch or traversed to the node, located to the right and below the internal node, while traversing the kd-tree 550 .
- one nibble of history bits per level is all that is needed to record the results of ray-bounding volume intersection tests and whether a path has been taken or not.
- the history bits at the preceding level(s) need to be examined.
- node history bits at that level and below should be cleared and a different path from a higher level should be taken.
- FIG. 6 is a flowchart illustrating a method 600 for traversing a kd-Tree.
- the method 600 beings at step 605 when an image processing system issues a ray to be traced into a three dimensional scene.
- the image processing system may use the workload manager 205 to execute tasks related to traversing the kd-Tree with an issued ray.
- the image processing system starts at the root or world node. From the root node, the image processing system may proceed to step 615 where the image processing system may select a branch to take.
- Step 615 may initiate within the image processing system a sub-routine which traverses the kd-Tree according to node history bits as described in greater detail below with reference to FIG. 7 .
- FIG. 7 is a flowchart which illustrates the method of traversing the kd-Tree according to node history bits 500 .
- the method 700 begins at, step 705 , when the image processing system reaches an internal node (i.e., a node containing branches to sub-nodes).
- the image processing system may determine if there is node level history information corresponding to the issued ray. If not, the image processing system proceeds to step 715 where the workload manager 205 may perform ray-bounding volume intersection tests for each of the bounding volumes represented by the nodes branched to from the internal node currently being traversed.
- the image processing system may update the node level history bits corresponding to the node level.
- the image processing system may update the “hit node” bits 505 and 515 which represent whether or not the ray intersected the bounding volume corresponding to each of the nodes branched to from the internal node.
- the image processing system may proceed to step 725 .
- the image processing system may determine if both bounding volumes represented by the nodes which are branched to by the internal node were intersected by the ray. If both bounding volumes were intersected the image processing system may proceed to step 727 where the image processing system may select the path to the node nearest to the origin of the ray. However, if only one node was intersected, at step 729 the image processing system may select the path to the node which was intersected. After steps 727 and 729 , the image processing system may proceed to step 730 . At step 730 the image processing system updates the taken bit in the node level history to reflect the path/branch selected by the image processing system. After step 730 , the image processing system takes the selected path/branch at step 735 .
- the image processing system may proceed to step 740 .
- the image processing system may determine the lowest node depth that the image processing system has previously determined that a bounding volume was intersected by the ray, but the image processing system did not take the path/branch to that bounding volume.
- a ray which has stored node level history information is a ray that the image processing system has traversed the spatial index (e.g., the kd-Tree) with, however the ray did not intersect a primitive within the bounding volume against which ray-primitive intersection tests were run (i.e., a miss occurred).
- the image processing system may specifically look for the occurrence of a ‘10’ in a node level history. The image processing system may look for a ‘10’ in either the pair which makes up the most significant two bits of the node level history, or the pair of bits which makes up the least significant two bits of the node level history.
- a ‘10’ in either of those two pairs represents that the bounding volume represented by that node was intersected by the ray, but a ray primitive intersection test has yet to be run for one of the bounding volumes beneath that node level (i.e., that corresponding path was not taken).
- a ray may intersect both bounding volumes represented by the sub-nodes beneath an internal node.
- the image processing system may have determined during a previous traversal of the kd-Tree that the bounding volume represented by the sub-node to the left and below the internal node of the kd-Tree was intersected by the ray before the bounding volume represented by the sub-node to the right and below the internal node.
- the image processing system may have taken the sub-node on the left and a history bit may have been updated to show such traversal.
- the node history bits corresponding to this internal node level would be ‘1110’ which can be read as: hit left node, took branch to left node, hit right node, branch to right node not yet taken.
- the sub-node to the right and below the internal node was intersected by the ray but has not been tested for a ray-primitive intersection, as is represented by the ‘10’ in the internal node level history.
- the image processing system may proceed to step 745 .
- the image processing system may clear all of the node level history bits for internal node levels below the lowest node level where a bounding volume was intersected but not taken level. This step ensures that as the image processing system traverses the kd-Tree, any history previously recorded for branches, nodes, or leaf nodes below the point at which an incorrect traversal path decision was made does not affect the future traversal of the kd-Tree.
- the image processing system may traverse the kd-Tree based on the node level history from the root node to the lowest node depth at which a bounding volume was intersected but not taken. Step 750 may ensure that the proper pointers to internal nodes on lower levels or to leaf nodes are retrieved by the image processing system from the cache 230 .
- the image processing system selects the path/branch to the node that has not been taken by the image processing system (i.e., the path represented by the ‘10’ in the node history for the lowest node level where a bounding volume was intersected but not taken). After step 755 , the image processing system proceeds to step 730 . At step 730 the image processing system updates the taken bit in the node level history to reflect the path selected by the image processing system. After step 730 , the image processing system takes the selected path at step 735 .
- the image processing system After the path has been taken the image processing system returns to method 600 .
- the image processing system resumes the method 600 at step 620 .
- the image processing system determines whether the path taken has resulted in the image processing system reaching a leaf node. If not, the image processing system returns to step 615 to select a branch to take.
- the workload manager 205 may send, via the inboxes 115 or via the network 225 , the ray, the ray history data structure, and the leaf node information (e.g., pointers to the primitives bound by the leaf node) to a vector throughput engine 210 for ray-primitive intersection tests.
- the leaf node information e.g., pointers to the primitives bound by the leaf node
- the vector throughput engine 210 may execute the ray-primitive tests to determine whether or not the ray which hit the bounding volume represented by the leaf node actually hit any of the primitives contained within the bounding volume. If the ray did hit any of the primitives within the bounding volume, the vector throughput engine 210 may assign a color (e.g., the color of the primitive) to the ray. However, the vector throughput engine 210 may also determine that the ray did not hit any of the primitives within the bounding volume.
- a color e.g., the color of the primitive
- the vector throughput engine 210 returns the ray and an indication of whether or not the ray hit or missed the primitives contained within the bounding volume.
- the image processing system may then determine if the information returned by the vector throughput engine 210 indicates that the ray hit a primitive, or if the information indicates that the ray missed all of the primitives contained within the bounding volume.
- the image processing system may then assign the color returned from the vector throughput engine 210 to the pixel 335 on the monitor 310 through which the ray passed.
- the image processing system may then proceed to issue another ray to traverse the kd-Tree or perform other operations related to rendering the two dimensional picture from the three dimensional scene.
- the workload manager 205 may return to step 610 .
- the workload manager 205 may begin traversing the kd-Tree again starting at the root node, with the ray history helping to avoid unnecessarily re-running ray-bounding volume intersection tests, as well as avoiding traversing the tree to paths that lead to leaf nodes having primitives a given ray did not inersect.
- FIG. 8 illustrates an exemplary scene 800 which has been partitioned into bounding volumes (BV 1 -BV 5 ).
- FIG. 8 is similar to the scene used in FIG. 4 to illustrate the building of a kd-Tree.
- a ray 805 issued by the image processing system.
- the ray 805 may be used to traverse the kd-Tree.
- the ray intersects BV 2 at a first point 805 and exits BV 2 at a second point 815 .
- the ray intersects BV 3 and BV 4 at the second point 815 and exits BV 3 and BV 4 at a third point 820 .
- FIG. 9A is an exemplary kd-Tree 900 corresponding to the partitioned scene 800 in FIG. 8 .
- FIG. 9A also illustrates a first nibble 905 of an exemplary internal node history data structure associated with the ray 805 and the first level of the kd-Tree 900 (i.e., the root node BV 1 ).
- FIG. 9A illustrates the initial state (all bits unasserted) of the node history data structure before the workload manager 205 has begun traversing the kd-Tree with the ray 805 .
- the workload manager 205 may perform operations related to traversing the kd-Tree 900 after a ray 805 has been issued by the image processing system. For example, as was described in step 615 of method 600 , the workload manager 205 may execute ray-bounding volume intersection tests to determine if the ray 805 intersects the bounding volumes corresponding to the child nodes, BV 2 and BV 3 , of the root node BV 1 . As can be seen in FIG. 8 , the ray 805 intersects both of the bounding volumes corresponding to the child nodes, BV 2 and BV 3 . The ray 805 intersects BV 2 at a first point 810 , and exits BV 2 at a second point 815 . The ray intersects BV 3 at the second point 815 and exits BV 3 at a third point 820 .
- the workload manager 205 may update the node history nibble 905 corresponding to the root node BV 1 level to reflect the results of the ray-bounding volume intersection test.
- the updating of the root node level history nibble 905 is illustrated in FIG. 9B . Due to the fact that the ray 805 intersects both of the child nodes, BV 2 and BV 3 , the workload manager 205 may assert the “hit node” bits in the node level history which correspond to each of the child nodes, BV 2 and BV 3 .
- the workload manager 205 may assert the most significant bit of the root node level history 905 , which represents that the ray 805 hit the bounding volume corresponding to the left child node (BV 2 ). Furthermore, the workload manager 205 may assert the third most significant bit of the root node level history 905 , which represents that the ray 805 hit the bounding volume corresponding to the right child node (BV 3 ).
- the workload manager 205 may determine a path to be taken down the kd-Tree 900 based on the bounding volume intersection tests. As illustrated in FIG. 9C , in one embodiment of the invention, if both child nodes, BV 2 and BV 3 , of the parent node BV 1 , in this case the root node, the workload manager 205 may proceed to the first (e.g., nearest) bounding volume which was intersected by the ray. In the immediate example, the ray 805 first intersects BV 2 . Therefore, the workload manager 205 may traverse to BV 2 and update the root node level history 905 to show the workload manager 205 “took” the branch to BV 2 (i.e., took left node). The updating of the node level history for the root node is illustrated in FIG. 9C .
- the workload manager 205 may now determine whether or not the BV 2 is a leaf node (i.e., a node that does not branch to other nodes). Since the node BV 2 is a leaf node, the workload manager 205 may now send the ray 805 , the node history 905 and 910 for the ray, and pointers to the primitives contained within the leaf node BV 2 to the vector throughput engine 210 as illustrated in FIG. 9D . The vector throughput engine 210 may then execute ray-primitive intersection tests to determine if the ray 805 intersects (hits) any primitives contained within BV 2 .
- the vector throughput engine 210 may return the ray and the corresponding history to the workload manager 205 indicating that the ray 805 did not intersect any primitives within BV 2 (i.e., a miss).
- the workload manager 205 may determine that the ray node level history contains information.
- the workload manager 205 may utilize the history to facilitate traversal of the kd-Tree.
- the workload manager 205 may utilize the ray history to determine the lowest level node history indicating where a bounding volume was intersected but a corresponding branch was not taken. This may be accomplished by determining the lowest node history which contains a ‘10’ in the node history.
- the workload manager 205 may determine that the root node level of the kd-Tree is the lowest level on the kd-Tree where a bounding volume was intersected but not taken.
- the workload manager 205 may clear the node level history for all node levels below the root node.
- the workload manager 205 may begin traversing the kd-Tree 900 at the root node BV 1 .
- the workload manager 205 may then use the node level history 905 to aid in traversal of the kd-tree 900 .
- the workload manager may determine to take the branch that has yet to be taken.
- the workload manager may determine that both the left and the right node were intersected by the ray 805 . This may be determined by examining the first and the third bits of the root node level history nibble 905 .
- Both of these bits are asserted (i.e., a ‘1’), and therefore both were determined to have been intersected in a previous ray-bounding volume intersection test.
- the workload manager 205 may determine that the workload manager previously “took” the branch to the left sub-node (i.e., sent the ray to be tested against the primitives contained within BV 2 ). This is determined by examining the second bit of the node level history, which is asserted. Therefore, the workload manager may not proceed to or “take” the other branch to the right node (i.e., BV 3 ) which was intersected by the ray 805 . As illustrated in FIG. 9F , the workload manager 205 may also update the took right bit of the root node level history nibble 905 to indicate the traversal to BV 3 .
- the workload manager 205 may determine if the traversed to node BV 3 is a leaf node. As can be seen in FIG. 9E , the node BV 3 is not a leaf node, but an internal node. Therefore, the workload manager 205 may execute ray-bounding volume intersection tests to determine if the ray 805 intersects the bounding volumes corresponding to the nodes beneath or on a lower level than BV 3 (i.e., BV 4 and BV 5 ).
- the workload manager 205 may now update the BV 3 node level history 910 to reflect the results of the ray-bounding volume intersection tests. Therefore, as illustrated in FIG. 9F , the workload manager 205 may place a “1,” or assert the bit, in the most significant bit location within the BV 3 node history 910 to reflect the fact that the ray intersects BV 3 . Next, the workload manager 205 may determine what branch/path “to take,” based on the BV 3 node level history 910 .
- the workload manager 205 may determine that only one node beneath BV 3 is intersected by the ray 805 , and therefore the workload manager 205 may traverse to the intersected node BV 4 . As illustrated in FIG. 9G , the workload manager 205 may update the BV 3 node level history 910 to reflect the traversal from node BV 3 to node BV 4 by asserting the second most significant bit (indicating left branch taken) in the BV 3 node level history.
- the workload manager 205 may now determine whether or not the left child node, BV 4 is a leaf node (i.e., the node does not have children). Since the node BV 4 is a leaf node, the workload manager 205 may now send the ray 805 , the node level history ( 905 and 910 ) for the ray, and pointers to the primitives contained within the leaf node BV 4 to the vector throughput engine 210 . The vector throughput engine 210 may then execute ray-primitive intersection tests to determine if the ray 805 intersects (hits) any primitives contained within BV 4 . As can be seen in FIG. 8 , the ray 805 intersects a primitive within BV 4 . Therefore, the vector throughput engine 210 may assign a color to the pixel through which the ray 805 passed and return the information to the workload manager 205 .
- Embodiments of the invention provide techniques and systems for recording the traversal history of a ray through a spatial index structure and utilizing the recorded traversal history of a ray through the spatial index.
- An image processing system may initially determine which nodes a ray intersects as it traverses through a spatial index. Results of the node intersection determinations may be recorded as the ray traverses the spatial index, and the recorded determinations may be associated with the ray. Furthermore, the image processing system may decide upon a traversal path based upon some probability of striking primitives corresponding to the nodes which make up the spatial index. This traversal path may also be recorded and associated with the ray. If the image processing system needs to traverse the spatial index at a later time, the recorded traversal history may be used to eliminate the need to recalculate ray-node intersections, and eliminate duplicating incorrect traversal path determinations.
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Abstract
Description
- 1. Field of the Invention
- Embodiments of the invention generally relate to the field of image processing.
- 2. Description of the Related Art
- The process of rendering two-dimensional images from three-dimensional scenes is commonly referred to as image processing. As the modern computer industry evolves image processing evolves as well. One particular goal in the evolution of image processing is to make two-dimensional simulations or renditions of three-dimensional scenes as realistic as possible. One limitation of rendering realistic images is that modern monitors display images through the use of pixels.
- A pixel is the smallest area of space which can be illuminated on a monitor. Most modern computer monitors will use a combination of hundreds of thousands or millions of pixels to compose the entire display or rendered scene. The individual pixels are arranged in a grid pattern and collectively cover the entire viewing area of the monitor. Each individual pixel may be illuminated to render a final picture for viewing.
- One technique for rendering a real world three-dimensional scene onto a two-dimensional monitor using pixels is called rasterization. Rasterization is the process of taking a two-dimensional image represented in vector format (mathematical representations of geometric objects within a scene) and converting the image into individual pixels for display on the monitor. Rasterization is effective at rendering graphics quickly and using relatively low amounts of computational power; however, rasterization suffers from some drawbacks. For example, rasterization often suffers from a lack of realism because it is not based on the physical properties of light, rather rasterization is based on the shape of three-dimensional geometric objects in a scene projected onto a two dimensional plane. Furthermore, the computational power required to render a scene with rasterization scales directly with an increase in the complexity of the scene to be rendered. As image processing becomes more realistic, rendered scenes also become more complex. Therefore, rasterization suffers as image processing evolves, because rasterization scales directly with complexity.
- Another technique for rendering a real world three-dimensional scene onto a two-dimensional monitor using pixels is called ray tracing. The ray tracing technique traces the propagation of imaginary rays, rays which behave similar to rays of light, into a three-dimensional scene which is to be rendered onto a computer screen. The rays originate from the eye(s) of a viewer sitting behind the computer screen and traverse through pixels, which make up the computer screen, towards the three-dimensional scene. Each traced ray proceeds into the scene and may intersect with objects within the scene. If a ray intersects an object within the scene, properties of the object and several other contributing factors are used to calculate the amount of color and light, or lack thereof, the ray is exposed to. These calculations are then used to determine the final color of the pixel through which the traced ray passed.
- The process of tracing rays is carried out many times for a single scene. For example, a single ray may be traced for each pixel in the display. Once a sufficient number of rays have been traced to determine the color of all of the pixels which make up the two-dimensional display of the computer screen, the two dimensional synthesis of the three-dimensional scene can be displayed on the computer screen to the viewer.
- Ray tracing typically renders real world three dimensional scenes with more realism than rasterization. This is partially due to the fact that ray tracing simulates how light travels and behaves in a real world environment, rather than simply projecting a three dimensional shape onto a two dimensional plane as is done with rasterization. Therefore, graphics rendered using ray tracing more accurately depict on a monitor what our eyes are accustomed to seeing in the real world.
- Furthermore, ray tracing also handles increases in scene complexity better than rasterization as scenes become more complex. Ray tracing scales logarithmically with scene complexity. This is due to the fact that the same number of rays may be cast into a scene, even if the scene becomes more complex. Therefore, ray tracing does not suffer in terms of computational power requirements as scenes become more complex as rasterization does.
- One major drawback of ray tracing is the large number of calculations, and thus processing power, required to render scenes. This leads to problems when fast rendering is needed. For example, when an image processing system is to render graphics for animation purposes such as in a game console. Due to the increased computational requirements for ray tracing it is difficult to render animation quickly enough to seem realistic (realistic animation is approximately twenty to twenty-four frames per second).
- Therefore, there exists a need for more efficient techniques and devices to perform ray tracing.
- Embodiments of the present invention generally provide methods and apparatus for performing ray tracing.
- According to one embodiment of the invention a method of ray tracing utilizing a spatial index having nodes defining bounded volumes of a three dimensional scene is provided. The method generally comprising: generating a ray into the scene; traversing the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; recording a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determining if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traversing the spatial index using the recorded traversal history.
- According to another embodiment of the invention a computer readable medium containing a program which, when executed, performs an operation for ray tracing utilizing a spatial index having nodes defining bounded volumes of a three dimensional scene is provided. The operation generally comprising: generating a ray into the scene; traversing the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; recording a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determining if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traversing the spatial index using the recorded traversal history.
- According to another embodiment of the invention a system, is provided. The system generally comprising a spatial index having nodes defining bounded volumes of a three dimensional scene; and a first processing element, wherein the first processing element is generally configured to: generate a ray into the scene; traverse the spatial index by taking branches from internal nodes until a leaf node is reached, wherein branches are taken based on whether the ray intersects bounding volumes defined by the nodes; record a traversal history indicating one or more nodes defining bounding volumes the ray intersects and branches taken when traversing the spatial index; determine if the ray hits a primitive contained in the bounding volume defined by the leaf node; and if the ray does not hit a primitive contained in the bounding volume defined by the leaf node, re-traverse the spatial index using the recorded traversal history.
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FIG. 1 illustrates a multiple core processing element, according to one embodiment of the invention. -
FIG. 2 illustrates multiple core processing element network, according to one embodiment of the invention. -
FIG. 3 is an exemplary three dimensional scene to be rendered by an image processing system, according to one embodiment of the invention. -
FIGS. 4A-4C illustrate a two dimensional space to be rendered by an image processing system and a corresponding spatial index created by an image processing system, according to one embodiment of the invention. -
FIG. 5 illustrates a spatial index and a corresponding data structure for storing traversal history of a ray through the spatial index, according to one embodiment of the invention. -
FIGS. 6 and 7 are flowcharts illustrating methods for traversing a spatial index, according to one embodiment of the invention. -
FIG. 8 is an exemplary two dimensional space to be rendered by an image processing system, according to one embodiment of the invention. -
FIGS. 9A-9G illustrate the traversal of a ray through a spatial index, according to one embodiment of the invention. - Embodiments of the invention provide techniques and systems for recording the traversal history of a ray through a spatial index structure and utilizing the recorded traversal history of a ray through the spatial index. An image processing system may initially determine which nodes a ray intersects as it traverses through a spatial index. Results of the node intersection determinations may be recorded as the ray traverses the spatial index, and the recorded determinations may be associated with the ray. Furthermore, the image processing system may decide upon a traversal path based upon some probability of striking primitives corresponding to the nodes which make up the spatial index. This traversal path may also be recorded and associated with the ray. If the image processing system needs to re-traverse the spatial index at a later time, the recorded traversal history may be used to eliminate the need to recalculate ray-node intersections, and eliminate incorrect traversal path determinations.
- In the following, reference is made to embodiments of the invention. However, it should be understood that the invention is not limited to specific described embodiments. Instead, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement and practice the invention. Furthermore, in various embodiments the invention provides numerous advantages over the prior art. However, although embodiments of the invention may achieve advantages over other possible solutions and/or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the invention. Thus, the following aspects, features, embodiments and advantages are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the invention” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the appended claims except where explicitly recited in a claim(s).
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FIG. 1 illustrates a multiplecore processing element 100, according to one embodiment of the invention. The multiplecore processing element 100 includes a plurality of basic throughput engines 105 (BTEs). ABTE 105 may contain a plurality of processing threads and a core cache (e.g., an L1 cache). The processing threads located within each BTE may have access to a shared multiple core processing element cache 110 (e.g., an L2 cache). - The
BTEs 105 may also have access to a plurality ofinboxes 115. Theinboxes 115 may be memory mapped address space. Theinboxes 115 may be mapped to the processing threads located within each of theBTEs 105. Each thread located within the BTEs may have a memory mapped inbox and access to all of the other memory mapped inboxes 115. Theinboxes 115 make up a low latency and high bandwidth communications network used by theBTEs 105. - The BTEs may use the
inboxes 115 as a network to communicate with each other and redistribute data processing work amongst the BTEs. For some embodiments, separate outboxes may be used in the communications network, for example, to receive the results of processing byBTEs 105. For other embodiments,inboxes 115 may also serve as outboxes, for example, with oneBTE 105 writing the results of a processing function directly to the inbox of anotherBTE 105 that will use the results. - The aggregate performance of an image processing system may be tied to how well the BTEs can partition and redistribute work. The network of
inboxes 115 may be used to collect and distribute work to other BTEs without corrupting the shared multiple coreprocessing element cache 110 with BTE communication data packets that have no frame to frame coherency. An image processing system which can render many millions of triangles per frame may includemany BTEs 105 connected in this manner. - In one embodiment of the invention, the threads of one
BTE 105 may be assigned to a workload manager. An image processing system may use various software and hardware components to render a two dimensional image from a three dimensional scene. According to one embodiment of the invention, an image processing system may use a workload manager to traverse a spatial index with a ray issued by the image processing system. A spatial index, as described further below with regards toFIG. 4 , may be implemented as a tree type data structure used to partition a relatively large three dimensional scene into smaller bounding volumes. An image processing system using a ray tracing methodology for image processing may use a spatial index to quickly determine ray-bounding volume intersections. In one embodiment of the invention, the workload manager may perform ray-bounding volume intersection tests by using the spatial index. - In one embodiment of the invention, other threads of the multiple core
processing element BTEs 105 on the multiplecore processing element 100 may be vector throughput engines. After a workload manager determines a ray-bounding volume intersection, the workload manager may issue (send), via theinboxes 115, the ray to one of a plurality of vector throughput engines. The vector throughput engines may then determine if the ray intersects a primitive contained within the bounding volume. The vector throughput engines may also perform operations relating to determining the color of the pixel through which the ray passed. -
FIG. 2 illustrates a network of multiplecore processing elements 200, according to one embodiment of the invention.FIG. 2 also illustrates one embodiment of the invention where the threads of one of the BTEs of the multiplecore processing element 100 is aworkload manager 205. Each multiplecore processing element 220 1-N in the network of multiplecore processing elements 200 may contain oneworkload manager 205 1-N, according to one embodiment of the invention. Eachprocessor 220 in the network of multiplecore processing elements 200 may also contain a plurality ofvector throughput engines 210, according to one embodiment of the invention. - The
workload managers 220 1-N may use ahigh speed bus 225 to communicate withother workload managers 220 1-N and/orvector throughput engines 210 of other multiplecore processing elements 220, according to one embodiment of the invention. Each of thevector throughput engines 210 may use thehigh speed bus 225 to communicate with othervector throughput engines 210 or theworkload managers 205. Theworkload manager processors 205 may use thehigh speed bus 225 to collect and distribute image processing related tasks to otherworkload manager processors 205, and/or distribute tasks to othervector throughput engines 210. The use of ahigh speed bus 225 may allow theworkload managers 205 1-N to communicate without affecting thecaches 230 with data packets related toworkload manager 205 communications. -
FIG. 3 is an exemplary threedimensional scene 305 to be rendered by an image processing system. Within the threedimensional scene 305 may be objects 320. The objects 320 inFIG. 3 are of different geometric shapes. Although only four objects 320 are illustrated inFIG. 3 , the number of objects in a typical three dimensional scene may be more or less. Commonly, three dimensional scenes will have many more objects than illustrated inFIG. 3 . - As can be seen in
FIG. 3 the objects are of varying geometric shape and size. For example, one object inFIG. 3 is a pyramid 320 A. Other objects inFIG. 3 are boxes 320 B-D. In many modern image processing systems objects are often broken up into smaller geometric shapes (e.g., squares, circles, triangles, etc.). The larger objects are then represented by a number of the smaller simple geometric shapes. These smaller geometric shapes are often referred to as primitives. - Also illustrated in the
scene 305 are light sources 325 A-B. The light sources may illuminate the objects 320 located within thescene 305. Furthermore, depending on the location of the light sources 325 and the objects 320 within thescene 305, the light sources may cause shadows to be cast onto objects within thescene 305. - The three
dimensional scene 305 may be rendered into a two-dimensional picture by an image processing system. The image processing system may also cause the two-dimensional picture to be displayed on amonitor 310. Themonitor 310 may usemany pixels 330 of different colors to render the final two-dimensional picture. - One method used by image processing systems to rendering a three-dimensional scene 320 into a two dimensional picture is called ray tracing. Ray tracing is accomplished by the image processing system “issuing” or “shooting” rays from the perspective of a
viewer 315 into the three-dimensional scene 320. The rays have properties and behavior similar to light rays. - One
ray 340, that originates at the position of theviewer 315 and traverses through the three-dimensional scene 305, can be seen inFIG. 3 . As theray 340 traverses from theviewer 315 to the three-dimensional scene 305, theray 340 passes through a plane where the final two-dimensional picture will be rendered by the image processing system. InFIG. 3 this plane is represented by themonitor 310. The point theray 340 passes through the plane, or monitor 310, is represented by apixel 335. - As briefly discussed earlier, most image processing systems use a
grid 330 of thousands (if not millions) of pixels to render the final scene on themonitor 310. Each individual pixel may display a different color to render the final composite two-dimensional picture on themonitor 310. An image processing system using a ray tracing image processing methodology to render a two dimensional picture from a three-dimensional scene will calculate the colors that the issued ray or rays encounters in the three dimensional scene. The image processing scene will then assign the colors encountered by the ray to the pixel through which the ray passed on its way from the viewer to the three-dimensional scene. - The number of rays issued per pixel may vary. Some pixels may have many rays issued for a particular scene to be rendered. In which case the final color of the pixel is determined by the each color contribution from all of the rays that were issued for the pixel. Other pixels may only have a single ray issued to determine the resulting color of the pixel in the two-dimensional picture. Some pixels may not have any rays issued by the image processing system, in which case their color may be determined, approximated or assigned by algorithms within the image processing system.
- To determine the final color of the
pixel 335 in the two dimensional picture, the image processing system must determine if theray 340 intersects an object within the scene. If the ray does not intersect an object within the scene it may be assigned a default background color (e.g., blue or black, representing the day or night sky). Conversely, as theray 340 traverses through the three dimensional scene theray 340 may strike objects. As the rays strike objects within the scene the color of the object may be assigned the pixel through which the ray passes. However, the color of the object must be determined before it is assigned to the pixel. - Many factors may contribute to the color of the object struck by the
original ray 340. For example, light sources within the three dimensional scene may illuminate the object. Furthermore, physical properties of the object may contribute to the color of the object. For example, if the object is reflective or transparent, other non-light source objects may then contribute to the color of the object. - In order to determine the effects from other objects within the three dimensional scene, secondary rays may be issued from the point where the
original ray 340 intersected the object. For example, one type of secondary ray may be a shadow ray. A shadow ray may be used to determine the contribution of light to the point where theoriginal ray 340 intersected the object. Another type of secondary ray may be a transmitted ray. A transmitted ray may be used to determine what color or light may be transmitted through the body of the object. Furthermore, a third type of secondary ray may be a reflected ray. A reflected ray may be used to determine what color or light is reflected onto the object. - As noted above, one type of secondary ray may be a shadow ray. Each shadow ray may be traced from the point of intersection of the original ray and the object, to a light source within the three-
dimensional scene 305. If the ray reaches the light source without encountering another object before the ray reaches the light source, then the light source will illuminate the object struck by the original ray at the point where the original ray struck the object. - For example,
shadow ray 341 A may be issued from the point whereoriginal ray 340 intersected the object 320 A, and may traverse in a direction towards the light source 325 A. Theshadow ray 341 A reaches the light source 325 A without encountering any other objects 320 within thescene 305. Therefore, the light source 325 A will illuminate the object 320 A at the point where theoriginal ray 340 intersected the object 320 A. - Other shadow rays may have their path between the point where the original ray struck the object and the light source blocked by another object within the three-dimensional scene. If the object obstructing the path between the point on the object the original ray struck and the light source is opaque, then the light source will not illuminate the object at the point where the original ray struck the object. Thus, the light source may not contribute to the color of the original ray and consequently neither to the color of the pixel to be rendered in the two-dimensional picture. However, if the object is translucent or transparent, then the light source may illuminate the object at the point where the original ray struck the object.
- For example,
shadow ray 341 B may be issued from the point where theoriginal ray 340 intersected with the object 320 A, and may traverse in a direction towards the light source 325 B. In this example, the path of theshadow ray 341 B is blocked by an object 320 D. If the object 320 D is opaque, then the light source 325 B will not illuminate the object 320 A at the point where theoriginal ray 340 intersected the object 320 A. However, if the object 320 D which the shadow ray is translucent or transparent the light source 325 B may illuminate the object 320 A at the point where theoriginal ray 340 intersected the object 320 A. - Another type of secondary ray is a transmitted ray. A transmitted ray may be issued by the image processing system if the object with which the original ray intersected has transparent or translucent properties (e.g., glass). A transmitted ray traverses through the object at an angle relative to the angle at which the original ray struck the object. For example, transmitted
ray 344 is seen traversing through the object 320 A which theoriginal ray 340 intersected. - Another type of secondary ray is a reflected ray. If the object with which the original ray intersected has reflective properties (e.g. a metal finish), then a reflected ray will be issued by the image processing system to determine what color or light may be reflected by the object. Reflected rays traverse away from the object at an angle relative to the angle at which the original ray intersected the object. For example, reflected
ray 343 may be issued by the image processing system to determine what color or light may be reflected by the object 320 A which theoriginal ray 340 intersected. - The total contribution of color and light of all secondary rays (e.g., shadow rays, transmitted rays, reflected rays, etc.) will result in the final color of the pixel through which the original ray passed.
- One problem encountered when performing ray tracing is determining quickly and efficiently if an issued ray intersects any objects within the scene to be rendered. One methodology known by those of ordinary skill in the art to make the ray intersection determination more efficient is to use a spatial index. A spatial index divides a three-dimensional scene or world into smaller volumes (smaller relative to the entire three-dimensional scene) which may or may not contain primitives. An image processing system can then use the known boundaries of these smaller volumes to determine if a ray may intersect primitives contained within the smaller volumes. If a ray does intersect a volume containing primitives, then a ray intersection test can be run using the trajectory of the ray against the known location and dimensions of the primitives contained within that volume. If a ray does not intersect a particular volume then there is no need to run ray-primitive intersection tests against the primitives contained within that volume. Furthermore, if a ray intersects a bounding volume which does not contain primitives then there is no need to run ray-primitive intersections tests against that bounding volume. Thus, by reducing the number of ray-primitive intersection tests which may be necessary, the use of a spatial index greatly increases the performance of a ray tracing image processing system. Some examples of different spatial index acceleration data structures are octrees, k dimensional Trees (kd-Trees), and binary space partitioning trees (BSP trees). While several different spatial index structures exist, for ease of describing embodiments of the present invention, a kd-Tree will be used in the examples to follow. However, those skilled in the art will readily recognize that embodiments of the invention may be applied to any of the different types of spatial indexes.
- A kd-Tree uses axis aligned bounding volumes to partition the entire scene or space into smaller volumes. That is, the kd-Tree may divide a three dimensional space encompassed by a scene through the use of splitting planes which are parallel to known axes. The splitting planes partition a larger space into smaller bounding volumes. Together the smaller bounding volumes make up the entire space in the scene. The determination to partition (divide) a larger bounding volume into two smaller bounding volumes may be made by the image processing system through the use of a kd-tree construction algorithm.
- One criterion for determining when to partition a bounding volume into smaller volumes may be the number of primitives contained within the bounding volume. That is, as long as a bounding volume contains more primitives than a predetermined threshold, the tree construction algorithm may continue to divide volumes by drawing more splitting planes. Another criterion for determining when to partition a bounding volume into smaller volumes may be the amount of space contained within the bounding volume. Furthermore, a decision to continue partitioning the bounding volume may also be based on how many primitives may be intersected by the plane which creates the bounding volume.
- The partitioning of the scene may be represented by a binary tree structure made up of nodes, branches and leaves. Each internal node within the tree may represent a relatively large bounding volume, while the node may contain branches to sub-nodes which may represent two relatively smaller partitioned volumes resulting after a partitioning of the relatively large bounding volume by a splitting plane. In an axis-aligned kd-Tree, each internal node may contain only two branches to other nodes. The internal node may contain branches (i.e., pointers) to one or two leaf nodes. A leaf node is a node which is not further sub-divided into smaller volumes and contains pointers to primitives. An internal node may also contain branches to other internal nodes which are further sub-divided. An internal node may also contain the information needed to determine along what axis the splitting plane was drawn and where along the axis the splitting plane was drawn.
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FIGS. 4A-4C illustrate a two dimensional space to be rendered by an image processing system and a corresponding kd-tree. For simplicity, a two dimensional scene is used to illustrate the building of a kd-Tree, however kd-Trees may also be used to represent three dimensional scenes. In the two dimensional illustration ofFIGS. 4A-4C splitting lines are illustrated instead of splitting planes, and bounding areas are illustrated instead of bounding volumes as would be used in a three dimensional structure. However, one skilled in the art will quickly recognize that the concepts may easily be applied to a three dimensional scene containing objects. -
FIG. 4A illustrates a twodimensional scene 405 containing primitives 410 to be rendered in the final picture to be displayed on amonitor 310. The largest volume which represents the entire volume of the scene is encompassed by bounding volume 1 (BV1). In the corresponding kd-Tree this may be represented by thetop level node 450, also known as the root or world node. In one embodiment of an image processing system, an image processing system may continue to partition bounding volumes into smaller bounding volumes when the bounding volume contains, for example, more than two primitives. As noted earlier the decision to continue partitioning a bounding volume into smaller bounding volumes may be based on many factors, however for ease of explanation in this example the decision to continue partitioning a bounding volume is based only on the number of primitives. As can be seen inFIG. 4A , BV1 contains six primitives, therefore kd-Tree construction algorithm may partition BV1 into smaller bounding volumes. -
FIG. 4B illustrates the same twodimensional scene 405 as illustrated inFIG. 4A . However, inFIG. 4B the tree construction algorithm has partitioned BV1 into two smaller bounding volumes BV2 and BV3. The partitioning of BV1, was accomplished, by drawing a splittingplane SP 1 415 along the x-axis at point x1. This partitioning of BV1 is also reflected in the kd-Tree as the twonodes parent node BV 1 450. The internal node representing BV1 may now store information such as, but not limited to, pointers to the two nodes beneath BV1 (e.g., BV2 and BV3), along which axis the splitting plane was drawn (e.g., x-axis), and where along the axis the splitting plane was drawn (e.g., at point x1). - The kd-Tree construction algorithm may continue to partition bounding volume BV3 because it contains more than the predetermined threshold of primitives (e.g., more than two primitives). However, the kd-Tree construction algorithm may not continue to partition bounding volume BV2, because bounding volume BV2 contains less than or equal to the number of primitives (e.g., only two primitives 410 A). Nodes which are not partitioned or sub-divided any further, such as BV2, are referred to as leaf nodes.
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FIG. 4C illustrates the same twodimensional scene 405 as illustrated inFIG. 4B . However, inFIG. 4C the kd-Tree construction algorithm has partitioned BV3 into two smaller bounding volumes BV4 and BV5. The kd-construction algorithm has partitioned BV3 using a partitioning plane along the y-axis at point y1. Since BV3 has been partitioned into two sub-nodes it may now be referred to as an internal node. The partitioning of BV3 is also reflected in the kd-Tree as the twoleaf nodes - The internal node representing BV3 may store information such as, but not limited to, pointers to the two leaf nodes (i.e., BV4 and BV5), along which axis the splitting plane was drawn (i.e., y-axis), and where along the axis the splitting plane was drawn (i.e., at point y1).
- The kd-Tree construction algorithm may now stop partitioning the bounding volumes because all bounding volumes located within the scene contain less than or equal to the maximum predetermined number of primitives which may be enclosed within a bounding volume. The leaf nodes may contain pointers to the primitives which are enclosed within the bounding volumes each leaf represents. For example, leaf node BV2 may contain pointers to primitives 410 A, leaf node BV4 may contain pointers to
primitives 410B, and leaf node BV5 may contain pointers to primitives 410 C. - A ray tracing image processing system may use the
workload manager 205 to traverse the spatial index (kd-Tree). Traversing the kd-Tree may include selecting a branch to a node on a lower level (sub-node) of the kd-Tree to take or proceed to in order to determine if the ray intersects any primitives contained within the sub-node. Aworkload manager 205 may use the coordinates and trajectory of an issued ray to traverse or navigate through the kd-Tree. By executing ray-bounding volume intersection tests, theworkload manager 205 may determine if the ray intersects a plane of the bounding volumes represented by nodes within the kd-Tree structure. If the ray intersects a bounding volume which contains only primitives (i.e., a leaf node), then theworkload manager 205 may send the ray and associated information to avector throughput engine 210 for ray-primitive intersection tests. A ray-primitive intersection test may be executed to determine if the ray intersects the primitives within the bounding volume. This methodology results in fewer ray-primitive intersection tests needed to determine if a ray intersects an object within the scene, in comparison to running ray-primitive intersection tests for a ray against each primitive contained within the scene. - The resulting kd-Tree structure, or other spatial index structure, may be stored in a
processor cache 230. The kd-Tree and the size of corresponding data which comprises the kd-Tree may be optimized for storage in aprocessor cache 230. The storage of the kd-Tree in aprocessor cache 230 may allow aworkload manager 205 to traverse the kd-Tree with a ray that has been issued by the image processing system without having to retrieve the kd-Tree from memory every time a ray is issued by the image processing system. - A node history may be stored for each level of internal node depth within the spatial index (e.g., kd-Tree). The node level history may be used to store information relating to bounding volume-ray intersection tests and kd-Tree traversal. By saving the results of previous tests and kd-Tree traversal the image processing system may take advantage of prior test results to reduce the amount processing necessary to determine a ray-primitive intersection. According to one embodiment of the invention, node history bits for each level may be stored in a nibble of a node history data structure sent along with (e.g., appended to) the information which describes the ray.
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FIG. 5 illustrates an exemplary kd-Tree 550 and a corresponding exemplary nodehistory data structure 545, according to one embodiment of the invention. The exemplary kd-Tree 550 is illustrated as containing eight levels of internal node depth (L1-L8). According to one embodiment of the invention, the correspondingnode history 545 may contain the same number of nibbles as the kd-Tree 550 contains internal node levels (L1-L8). Therefore, according to one embodiment of the invention, thenode history 545 may contain eight nibbles (i.e., 32 bits) which may record the history of ray-intersection tests and kd-Tree traversal. According to one embodiment of the invention, the most significant nibble L1 may correspond to the first level L1 (i.e., the root or world node) within the kd-Tree 550 and the least significant nibble L8 may correspond to the lowest level L8 within the kd-tree 550. - Each nibble within the node
history data structure 545 may contain four bits. The two mostsignificant bits 525 of each nibble may correspond to a node located to the left and below an internal node. The two leastsignificant bits 530 of each nibble may relate to a node located to the right and below an internal node. The mostsignificant bit 505 of each nibble may be set (e.g., to a high state, or a “1”) if the ray-bounding volume intersection test was executed and the ray intersected the bounding volume represented by the node to the left and below an internal node. The second mostsignificant bit 505 may be set if theworkload manager 205 “took” the branch or traversed to the node, located to the left and below the internal node, while traversing the kd-tree. As used herein, a path is considered “taken” if the kd-tree was traversed to reach an internal or leaf node along the path. - The third most
significant bit 515 may be set if the ray-bounding volume intersection test was executed and the ray intersected the bounding volume represented by the node located to the right and below the internal node. The leastsignificant bit 520 may be set if theworkload manager 205 “took” the branch or traversed to the node, located to the right and below the internal node, while traversing the kd-tree 550. - Thus, one nibble of history bits per level is all that is needed to record the results of ray-bounding volume intersection tests and whether a path has been taken or not. Of course, to determine which node has been reached at any particular level, the history bits at the preceding level(s) need to be examined. Thus, once all paths at a particular level have been taken when searching for a leaf node with primitives that a given ray intersects, node history bits at that level and below should be cleared and a different path from a higher level should be taken.
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FIG. 6 is a flowchart illustrating amethod 600 for traversing a kd-Tree. Themethod 600 beings atstep 605 when an image processing system issues a ray to be traced into a three dimensional scene. The image processing system may use theworkload manager 205 to execute tasks related to traversing the kd-Tree with an issued ray. Next, atstep 610, the image processing system starts at the root or world node. From the root node, the image processing system may proceed to step 615 where the image processing system may select a branch to take. - Step 615 may initiate within the image processing system a sub-routine which traverses the kd-Tree according to node history bits as described in greater detail below with reference to
FIG. 7 . -
FIG. 7 is a flowchart which illustrates the method of traversing the kd-Tree according to node history bits 500. Themethod 700 begins at,step 705, when the image processing system reaches an internal node (i.e., a node containing branches to sub-nodes). Next, atstep 710, the image processing system may determine if there is node level history information corresponding to the issued ray. If not, the image processing system proceeds to step 715 where theworkload manager 205 may perform ray-bounding volume intersection tests for each of the bounding volumes represented by the nodes branched to from the internal node currently being traversed. Next, atstep 720, the image processing system may update the node level history bits corresponding to the node level. Specifically, the image processing system may update the “hit node”bits - At
step 725 the image processing system may determine if both bounding volumes represented by the nodes which are branched to by the internal node were intersected by the ray. If both bounding volumes were intersected the image processing system may proceed to step 727 where the image processing system may select the path to the node nearest to the origin of the ray. However, if only one node was intersected, atstep 729 the image processing system may select the path to the node which was intersected. Aftersteps step 730 the image processing system updates the taken bit in the node level history to reflect the path/branch selected by the image processing system. Afterstep 730, the image processing system takes the selected path/branch atstep 735. - If, at
step 710, the image processing system determined that the ray did have node level history information, the image processing system may proceed to step 740. Atstep 740, the image processing system may determine the lowest node depth that the image processing system has previously determined that a bounding volume was intersected by the ray, but the image processing system did not take the path/branch to that bounding volume. - A ray which has stored node level history information is a ray that the image processing system has traversed the spatial index (e.g., the kd-Tree) with, however the ray did not intersect a primitive within the bounding volume against which ray-primitive intersection tests were run (i.e., a miss occurred). After a miss, in order to determine the lowest internal node depth at which a bounding volume was intersected but not taken, the image processing system may specifically look for the occurrence of a ‘10’ in a node level history. The image processing system may look for a ‘10’ in either the pair which makes up the most significant two bits of the node level history, or the pair of bits which makes up the least significant two bits of the node level history. A ‘10’ in either of those two pairs represents that the bounding volume represented by that node was intersected by the ray, but a ray primitive intersection test has yet to be run for one of the bounding volumes beneath that node level (i.e., that corresponding path was not taken).
- For example, at a certain level of the kd-Tree a ray may intersect both bounding volumes represented by the sub-nodes beneath an internal node. The image processing system may have determined during a previous traversal of the kd-Tree that the bounding volume represented by the sub-node to the left and below the internal node of the kd-Tree was intersected by the ray before the bounding volume represented by the sub-node to the right and below the internal node. The image processing system may have taken the sub-node on the left and a history bit may have been updated to show such traversal.
- As an example, according to one embodiment of the invention, if each node level is represented by a nibble, the node history bits corresponding to this internal node level would be ‘1110’ which can be read as: hit left node, took branch to left node, hit right node, branch to right node not yet taken. The sub-node to the right and below the internal node was intersected by the ray but has not been tested for a ray-primitive intersection, as is represented by the ‘10’ in the internal node level history.
- After determining the lowest node level history where a bounding volume was intersected but not taken the image processing system may proceed to step 745. At
step 745 the image processing system may clear all of the node level history bits for internal node levels below the lowest node level where a bounding volume was intersected but not taken level. This step ensures that as the image processing system traverses the kd-Tree, any history previously recorded for branches, nodes, or leaf nodes below the point at which an incorrect traversal path decision was made does not affect the future traversal of the kd-Tree. - Next, at
step 750, the image processing system may traverse the kd-Tree based on the node level history from the root node to the lowest node depth at which a bounding volume was intersected but not taken. Step 750 may ensure that the proper pointers to internal nodes on lower levels or to leaf nodes are retrieved by the image processing system from thecache 230. Next, atstep 755, the image processing system selects the path/branch to the node that has not been taken by the image processing system (i.e., the path represented by the ‘10’ in the node history for the lowest node level where a bounding volume was intersected but not taken). Afterstep 755, the image processing system proceeds to step 730. Atstep 730 the image processing system updates the taken bit in the node level history to reflect the path selected by the image processing system. Afterstep 730, the image processing system takes the selected path atstep 735. - After the path has been taken the image processing system returns to
method 600. The image processing system resumes themethod 600 atstep 620. Atstep 620, the image processing system determines whether the path taken has resulted in the image processing system reaching a leaf node. If not, the image processing system returns to step 615 to select a branch to take. - However, if the
workload manager 205 determined atstep 620 that the path taken resulted in theworkload manager 205 reaching a leaf node, theworkload manager 205 may send, via theinboxes 115 or via thenetwork 225, the ray, the ray history data structure, and the leaf node information (e.g., pointers to the primitives bound by the leaf node) to avector throughput engine 210 for ray-primitive intersection tests. - The
vector throughput engine 210 may execute the ray-primitive tests to determine whether or not the ray which hit the bounding volume represented by the leaf node actually hit any of the primitives contained within the bounding volume. If the ray did hit any of the primitives within the bounding volume, thevector throughput engine 210 may assign a color (e.g., the color of the primitive) to the ray. However, thevector throughput engine 210 may also determine that the ray did not hit any of the primitives within the bounding volume. - Some time later, the
vector throughput engine 210 returns the ray and an indication of whether or not the ray hit or missed the primitives contained within the bounding volume. The image processing system, atstep 630, may then determine if the information returned by thevector throughput engine 210 indicates that the ray hit a primitive, or if the information indicates that the ray missed all of the primitives contained within the bounding volume. - If the ray hit a primitive, the image processing system may then assign the color returned from the
vector throughput engine 210 to thepixel 335 on themonitor 310 through which the ray passed. The image processing system may then proceed to issue another ray to traverse the kd-Tree or perform other operations related to rendering the two dimensional picture from the three dimensional scene. - If the
vector throughput engine 210 determined that the ray missed the primitives contained within the bounding volume, theworkload manager 205 may return to step 610. Atstep 610, theworkload manager 205 may begin traversing the kd-Tree again starting at the root node, with the ray history helping to avoid unnecessarily re-running ray-bounding volume intersection tests, as well as avoiding traversing the tree to paths that lead to leaf nodes having primitives a given ray did not inersect. -
FIG. 8 illustrates an exemplary scene 800 which has been partitioned into bounding volumes (BV1-BV5).FIG. 8 is similar to the scene used inFIG. 4 to illustrate the building of a kd-Tree. Also illustrated inFIG. 8 is aray 805 issued by the image processing system. Theray 805 may be used to traverse the kd-Tree. The ray intersects BV2 at afirst point 805 and exits BV2 at asecond point 815. The ray intersects BV3 and BV4 at thesecond point 815 and exits BV3 and BV4 at athird point 820. -
FIG. 9A is an exemplary kd-Tree 900 corresponding to the partitioned scene 800 inFIG. 8 .FIG. 9A also illustrates afirst nibble 905 of an exemplary internal node history data structure associated with theray 805 and the first level of the kd-Tree 900 (i.e., the root node BV1). Furthermore, also illustrated is asecond nibble 910 of the exemplary internal node history data structure associated with theray 805 and the second level of the kd-Tree.FIG. 9A illustrates the initial state (all bits unasserted) of the node history data structure before theworkload manager 205 has begun traversing the kd-Tree with theray 805. - As described with respect to method 500 in
FIG. 5 , theworkload manager 205 may perform operations related to traversing the kd-Tree 900 after aray 805 has been issued by the image processing system. For example, as was described instep 615 ofmethod 600, theworkload manager 205 may execute ray-bounding volume intersection tests to determine if theray 805 intersects the bounding volumes corresponding to the child nodes, BV2 and BV3, of the root node BV1. As can be seen inFIG. 8 , theray 805 intersects both of the bounding volumes corresponding to the child nodes, BV2 and BV3. Theray 805 intersects BV2 at afirst point 810, and exits BV2 at asecond point 815. The ray intersects BV3 at thesecond point 815 and exits BV3 at athird point 820. - After the
workload manager 205 has executed the ray-bounding volume intersection tests, theworkload manager 205 may update thenode history nibble 905 corresponding to the root node BV1 level to reflect the results of the ray-bounding volume intersection test. The updating of the root nodelevel history nibble 905 is illustrated inFIG. 9B . Due to the fact that theray 805 intersects both of the child nodes, BV2 and BV3, theworkload manager 205 may assert the “hit node” bits in the node level history which correspond to each of the child nodes, BV2 and BV3. Therefore, theworkload manager 205 may assert the most significant bit of the rootnode level history 905, which represents that theray 805 hit the bounding volume corresponding to the left child node (BV2). Furthermore, theworkload manager 205 may assert the third most significant bit of the rootnode level history 905, which represents that theray 805 hit the bounding volume corresponding to the right child node (BV3). - Next, the
workload manager 205 may determine a path to be taken down the kd-Tree 900 based on the bounding volume intersection tests. As illustrated inFIG. 9C , in one embodiment of the invention, if both child nodes, BV2 and BV3, of the parent node BV1, in this case the root node, theworkload manager 205 may proceed to the first (e.g., nearest) bounding volume which was intersected by the ray. In the immediate example, theray 805 first intersects BV2. Therefore, theworkload manager 205 may traverse to BV2 and update the rootnode level history 905 to show theworkload manager 205 “took” the branch to BV2 (i.e., took left node). The updating of the node level history for the root node is illustrated inFIG. 9C . - The
workload manager 205 may now determine whether or not the BV2 is a leaf node (i.e., a node that does not branch to other nodes). Since the node BV2 is a leaf node, theworkload manager 205 may now send theray 805, thenode history vector throughput engine 210 as illustrated inFIG. 9D . Thevector throughput engine 210 may then execute ray-primitive intersection tests to determine if theray 805 intersects (hits) any primitives contained within BV2. - As illustrated in
FIG. 8 , theray 805 does not intersect any primitives located within BV2. Therefore, thevector throughput engine 210 may return the ray and the corresponding history to theworkload manager 205 indicating that theray 805 did not intersect any primitives within BV2 (i.e., a miss). - After the ray is returned from the
vector throughput engine 210, theworkload manager 205 may determine that the ray node level history contains information. Theworkload manager 205 may utilize the history to facilitate traversal of the kd-Tree. Theworkload manager 205 may utilize the ray history to determine the lowest level node history indicating where a bounding volume was intersected but a corresponding branch was not taken. This may be accomplished by determining the lowest node history which contains a ‘10’ in the node history. Thus, as illustrated inFIG. 9E , theworkload manager 205 may determine that the root node level of the kd-Tree is the lowest level on the kd-Tree where a bounding volume was intersected but not taken. This may be determined by examining the rootnode level history 905 which contains a ‘10’ indicating a hit in a bounding volume corresponding to the right branch, but that the right branch was not taken. After determining that the root node level was the lowest level, theworkload manager 205 may clear the node level history for all node levels below the root node. - Next, the
workload manager 205 may begin traversing the kd-Tree 900 at the root node BV1. Theworkload manager 205 may then use thenode level history 905 to aid in traversal of the kd-tree 900. Based on thenode level history 905 for the root node, the workload manager may determine to take the branch that has yet to be taken. By examining thenode level history 905, the workload manager may determine that both the left and the right node were intersected by theray 805. This may be determined by examining the first and the third bits of the root nodelevel history nibble 905. Both of these bits are asserted (i.e., a ‘1’), and therefore both were determined to have been intersected in a previous ray-bounding volume intersection test. Furthermore, theworkload manager 205 may determine that the workload manager previously “took” the branch to the left sub-node (i.e., sent the ray to be tested against the primitives contained within BV2). This is determined by examining the second bit of the node level history, which is asserted. Therefore, the workload manager may not proceed to or “take” the other branch to the right node (i.e., BV3) which was intersected by theray 805. As illustrated inFIG. 9F , theworkload manager 205 may also update the took right bit of the root nodelevel history nibble 905 to indicate the traversal to BV3. - The
workload manager 205 may determine if the traversed to node BV3 is a leaf node. As can be seen inFIG. 9E , the node BV3 is not a leaf node, but an internal node. Therefore, theworkload manager 205 may execute ray-bounding volume intersection tests to determine if theray 805 intersects the bounding volumes corresponding to the nodes beneath or on a lower level than BV3 (i.e., BV4 and BV5). - As illustrated in
FIG. 8 theray 805 intersects BV4 atpoint 815, however the ray does not intersect BV5. Therefore, the results of the ray-bounding volume intersection test may indicate that theray 805 does not intersect BV5. Theworkload manager 205 may now update the BV3node level history 910 to reflect the results of the ray-bounding volume intersection tests. Therefore, as illustrated inFIG. 9F , theworkload manager 205 may place a “1,” or assert the bit, in the most significant bit location within the BV3 node history 910 to reflect the fact that the ray intersects BV3. Next, theworkload manager 205 may determine what branch/path “to take,” based on the BV3node level history 910. - By examining the BV3
node level history 910 theworkload manager 205 may determine that only one node beneath BV3 is intersected by theray 805, and therefore theworkload manager 205 may traverse to the intersected node BV4. As illustrated inFIG. 9G , theworkload manager 205 may update the BV3node level history 910 to reflect the traversal from node BV3 to node BV4 by asserting the second most significant bit (indicating left branch taken) in the BV3 node level history. - The
workload manager 205 may now determine whether or not the left child node, BV4 is a leaf node (i.e., the node does not have children). Since the node BV4 is a leaf node, theworkload manager 205 may now send theray 805, the node level history (905 and 910) for the ray, and pointers to the primitives contained within the leaf node BV4 to thevector throughput engine 210. Thevector throughput engine 210 may then execute ray-primitive intersection tests to determine if theray 805 intersects (hits) any primitives contained within BV4. As can be seen inFIG. 8 , theray 805 intersects a primitive within BV4. Therefore, thevector throughput engine 210 may assign a color to the pixel through which theray 805 passed and return the information to theworkload manager 205. - Those skilled in the art will appreciate that when a ray does intersect with a primitive of a leaf node, additional rays may be spawned, for example, corresponding to reflection, transmission, refraction, and the like. While the iterative process of spawning such rays is well known, each of these rays may be efficiently traced using the techniques described herein to determine final pixel values.
- Embodiments of the invention provide techniques and systems for recording the traversal history of a ray through a spatial index structure and utilizing the recorded traversal history of a ray through the spatial index. An image processing system may initially determine which nodes a ray intersects as it traverses through a spatial index. Results of the node intersection determinations may be recorded as the ray traverses the spatial index, and the recorded determinations may be associated with the ray. Furthermore, the image processing system may decide upon a traversal path based upon some probability of striking primitives corresponding to the nodes which make up the spatial index. This traversal path may also be recorded and associated with the ray. If the image processing system needs to traverse the spatial index at a later time, the recorded traversal history may be used to eliminate the need to recalculate ray-node intersections, and eliminate duplicating incorrect traversal path determinations.
- While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims (20)
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
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Cited By (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080117206A1 (en) * | 2006-11-21 | 2008-05-22 | Robert Allen Shearer | Method for Improving Spatial Index Efficiency by Jittering Splitting Planes |
US20080122845A1 (en) * | 2006-11-28 | 2008-05-29 | Jeffrey Douglas Brown | Dynamic Determination of Optimal Spatial Index Mapping to Processor Thread Resources |
US20090096788A1 (en) * | 2007-10-12 | 2009-04-16 | Caustic Graphics, Inc. | Method and apparatus for increasing efficiency of transmission and/or storage of rays for parallelized ray intersection testing |
US20090128562A1 (en) * | 2007-11-19 | 2009-05-21 | Caustic Graphics, Inc. | Systems and methods for rendering with ray tracing |
US20090262132A1 (en) * | 2006-09-19 | 2009-10-22 | Caustic Graphics, Inc. | Architectures for parallelized intersection testing and shading for ray-tracing rendering |
US20090289939A1 (en) * | 2006-09-19 | 2009-11-26 | Caustic Graphics, Inc. | Systems and methods for concurrent ray tracing |
US20090322752A1 (en) * | 2006-09-19 | 2009-12-31 | Caustic Graphics, Inc. | Ray tracing system architectures and methods |
US20100228781A1 (en) * | 2009-02-24 | 2010-09-09 | International Business Machines Corporation | Resetting of Dynamically Grown Accelerated Data Structure |
US20100231589A1 (en) * | 2008-09-09 | 2010-09-16 | Caustic Graphics, Inc. | Ray tracing using ray-specific clipping |
US20110080403A1 (en) * | 2009-10-01 | 2011-04-07 | Manfred Ernst | Memory efficient ray tracing with hierarchical mesh quantization |
US20110304624A1 (en) * | 2010-06-14 | 2011-12-15 | Industry-Academic Cooperation Foundation Yonsei University | Method and apparatus for ray tracing in a 3-dimensional image system |
US20110316855A1 (en) * | 2010-06-24 | 2011-12-29 | International Business Machines Corporation | Parallelized Streaming Accelerated Data Structure Generation |
US20120050289A1 (en) * | 2010-08-26 | 2012-03-01 | Industry-Academic Cooperation Foundation, Yonsei Universtiy | Image processing apparatus and method |
US8212816B1 (en) * | 2007-12-17 | 2012-07-03 | Nvidia Corporation | System, method, and computer program product for parallel ray tracing traversal and intersection utilizing a single instruction multiple data (SIMD) processing architecture |
US8253730B1 (en) * | 2008-08-29 | 2012-08-28 | Adobe Systems Incorporated | System and method for construction of data structures for ray tracing using bounding hierarchies |
US8289324B1 (en) * | 2007-12-17 | 2012-10-16 | Nvidia Corporation | System, method, and computer program product for spatial hierarchy traversal |
US20120293515A1 (en) * | 2011-05-18 | 2012-11-22 | Clarberg Franz P | Rendering Tessellated Geometry With Motion and Defocus Blur |
US8502819B1 (en) * | 2007-12-17 | 2013-08-06 | Nvidia Corporation | System and method for performing ray tracing node traversal in image rendering |
US8629867B2 (en) | 2010-06-04 | 2014-01-14 | International Business Machines Corporation | Performing vector multiplication |
US8692834B2 (en) | 2011-06-16 | 2014-04-08 | Caustic Graphics, Inc. | Graphics processor with non-blocking concurrent architecture |
US8928675B1 (en) | 2014-02-13 | 2015-01-06 | Raycast Systems, Inc. | Computer hardware architecture and data structures for encoders to support incoherent ray traversal |
US20150109301A1 (en) * | 2013-10-22 | 2015-04-23 | Samsung Electronics Co., Ltd. | Apparatus and method of using acceleration structure in ray tracing |
US9030476B2 (en) | 2006-09-19 | 2015-05-12 | Imagination Technologies, Limited | Dynamic graphics rendering scheduling |
US20150138202A1 (en) * | 2013-11-20 | 2015-05-21 | Samsung Electronics Co., Ltd. | Method and apparatus for traversing binary tree in ray tracing system |
US9367949B2 (en) | 2012-09-17 | 2016-06-14 | Samsung Electronics Co., Ltd. | Apparatus and method for scheduling of ray tracing |
US9478062B2 (en) | 2006-09-19 | 2016-10-25 | Imagination Technologies Limited | Memory allocation in distributed memories for multiprocessing |
US20170061673A1 (en) * | 2015-08-31 | 2017-03-02 | Samsung Electronics Co., Ltd. | Method of generating and traversing acceleration structure |
US20170091898A1 (en) * | 2015-09-24 | 2017-03-30 | Samsung Electronics Co., Ltd. | Apparatus for and method of traversing tree |
US9665970B2 (en) | 2006-09-19 | 2017-05-30 | Imagination Technologies Limited | Variable-sized concurrent grouping for multiprocessing |
US9697640B2 (en) | 2014-04-21 | 2017-07-04 | Qualcomm Incorporated | Start node determination for tree traversal in ray tracing applications |
US9818221B2 (en) | 2016-02-25 | 2017-11-14 | Qualcomm Incorporated | Start node determination for tree traversal for shadow rays in graphics processing |
US9996966B2 (en) | 2013-11-04 | 2018-06-12 | Samsung Electronics Co., Ltd. | Ray tracing method and apparatus |
US10019830B2 (en) | 2014-04-02 | 2018-07-10 | Samsung Electronics Co., Ltd. | Method and apparatus for rendering same regions of multi frames |
US10061618B2 (en) | 2011-06-16 | 2018-08-28 | Imagination Technologies Limited | Scheduling heterogenous computation on multithreaded processors |
US10319139B2 (en) * | 2017-04-01 | 2019-06-11 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US11238640B2 (en) * | 2020-06-26 | 2022-02-01 | Advanced Micro Devices, Inc. | Early culling for ray tracing |
US12118398B2 (en) | 2018-07-20 | 2024-10-15 | Imagination Technologies Limited | Scheduling heterogeneous computation on multithreaded processors |
Families Citing this family (49)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7681020B2 (en) * | 2007-04-18 | 2010-03-16 | International Business Machines Corporation | Context switching and synchronization |
JP4487211B2 (en) * | 2007-06-01 | 2010-06-23 | カシオ計算機株式会社 | Connection control apparatus and network connection control program |
WO2009036100A2 (en) | 2007-09-10 | 2009-03-19 | Vanda Pharmaceuticals, Inc. | Prediction of qt prolongation based on snp genotype |
US7932905B2 (en) * | 2007-10-15 | 2011-04-26 | Caustic Graphics, Inc. | Method, apparatus, and computer readable medium for light energy accounting in ray tracing |
US8072460B2 (en) | 2007-10-17 | 2011-12-06 | Nvidia Corporation | System, method, and computer program product for generating a ray tracing data structure utilizing a parallel processor architecture |
US8190864B1 (en) * | 2007-10-25 | 2012-05-29 | Oracle America, Inc. | APIC implementation for a highly-threaded x86 processor |
US20090165004A1 (en) * | 2007-12-21 | 2009-06-25 | Jaideep Moses | Resource-aware application scheduling |
KR101536197B1 (en) | 2008-02-27 | 2015-07-13 | 삼성전자주식회사 | 3-dimensional image processor and processing method |
US8359487B2 (en) * | 2008-03-19 | 2013-01-22 | Sony Corporation | System and method for effectively performing a clock adjustment procedure |
US8082381B2 (en) * | 2008-09-02 | 2011-12-20 | Nvidia Corporation | Connecting a plurality of peripherals |
US8103803B2 (en) * | 2008-11-21 | 2012-01-24 | Nvidia Corporation | Communication between a processor and a controller |
US8610732B2 (en) * | 2008-12-11 | 2013-12-17 | Nvidia Corporation | System and method for video memory usage for general system application |
US8677074B2 (en) * | 2008-12-15 | 2014-03-18 | Nvidia Corporation | Shared memory access techniques |
US8495643B2 (en) * | 2009-06-30 | 2013-07-23 | International Business Machines Corporation | Message selection based on time stamp and priority in a multithreaded processor |
EP2454721B1 (en) * | 2009-07-14 | 2019-12-11 | Koninklijke Philips N.V. | Image reconstruction including shift-variant blur compensation |
US8443375B2 (en) * | 2009-12-14 | 2013-05-14 | Verisign, Inc. | Lockless queues |
US8619078B2 (en) * | 2010-05-21 | 2013-12-31 | International Business Machines Corporation | Parallelized ray tracing |
KR101705581B1 (en) | 2010-09-30 | 2017-02-22 | 삼성전자주식회사 | Data processing apparatus and method |
US8819700B2 (en) * | 2010-12-22 | 2014-08-26 | Lsi Corporation | System and method for synchronous inter-thread communication |
US9021237B2 (en) * | 2011-12-20 | 2015-04-28 | International Business Machines Corporation | Low latency variable transfer network communicating variable written to source processing core variable register allocated to destination thread to destination processing core variable register allocated to source thread |
US9304772B2 (en) | 2012-03-29 | 2016-04-05 | Advanced Micro Devices, Inc. | Ordering thread wavefronts instruction operations based on wavefront priority, operation counter, and ordering scheme |
US8972693B2 (en) * | 2012-03-29 | 2015-03-03 | Advanced Micro Devices, Inc. | Hardware managed allocation and deallocation evaluation circuit |
JP6070150B2 (en) * | 2012-12-14 | 2017-02-01 | 富士通株式会社 | Information processing apparatus, information processing apparatus control method, and information processing apparatus control program |
US9256573B2 (en) * | 2013-02-14 | 2016-02-09 | International Business Machines Corporation | Dynamic thread status retrieval using inter-thread communication |
US10558571B2 (en) * | 2014-03-20 | 2020-02-11 | Sybase, Inc. | Second level database file cache for row instantiation |
KR102219289B1 (en) * | 2014-05-27 | 2021-02-23 | 삼성전자 주식회사 | Apparatus and method for traversing acceleration structure in a ray tracing system |
US9645935B2 (en) | 2015-01-13 | 2017-05-09 | International Business Machines Corporation | Intelligent bandwidth shifting mechanism |
GB2540971B (en) * | 2015-07-31 | 2018-03-14 | Advanced Risc Mach Ltd | Graphics processing systems |
US10079916B2 (en) | 2015-08-13 | 2018-09-18 | Advanced Micro Devices, Inc. | Register files for I/O packet compression |
EP3411835B1 (en) * | 2016-02-05 | 2023-07-05 | DeepMind Technologies Limited | Augmenting neural networks with hierarchical external memory |
US9858704B2 (en) * | 2016-04-04 | 2018-01-02 | Intel Corporation | Reduced precision ray traversal with plane reuse |
US10552070B2 (en) | 2017-11-14 | 2020-02-04 | International Business Machines Corporation | Separation of memory-based configuration state registers based on groups |
US10761983B2 (en) | 2017-11-14 | 2020-09-01 | International Business Machines Corporation | Memory based configuration state registers |
US10558366B2 (en) | 2017-11-14 | 2020-02-11 | International Business Machines Corporation | Automatic pinning of units of memory |
US10642757B2 (en) | 2017-11-14 | 2020-05-05 | International Business Machines Corporation | Single call to perform pin and unpin operations |
US10761751B2 (en) | 2017-11-14 | 2020-09-01 | International Business Machines Corporation | Configuration state registers grouped based on functional affinity |
US10635602B2 (en) | 2017-11-14 | 2020-04-28 | International Business Machines Corporation | Address translation prior to receiving a storage reference using the address to be translated |
US10698686B2 (en) | 2017-11-14 | 2020-06-30 | International Business Machines Corporation | Configurable architectural placement control |
US10664181B2 (en) | 2017-11-14 | 2020-05-26 | International Business Machines Corporation | Protecting in-memory configuration state registers |
US10901738B2 (en) | 2017-11-14 | 2021-01-26 | International Business Machines Corporation | Bulk store and load operations of configuration state registers |
US10592164B2 (en) | 2017-11-14 | 2020-03-17 | International Business Machines Corporation | Portions of configuration state registers in-memory |
US10496437B2 (en) | 2017-11-14 | 2019-12-03 | International Business Machines Corporation | Context switch by changing memory pointers |
US10580196B1 (en) * | 2018-08-10 | 2020-03-03 | Nvidia Corporation | Method for continued bounding volume hierarchy traversal on intersection without shader intervention |
US11831565B2 (en) | 2018-10-03 | 2023-11-28 | Advanced Micro Devices, Inc. | Method for maintaining cache consistency during reordering |
CN109614220B (en) | 2018-10-26 | 2020-06-30 | 阿里巴巴集团控股有限公司 | Multi-core system processor and data updating method |
US10719974B1 (en) | 2018-12-28 | 2020-07-21 | Intel Corporation | Apparatus and method for efficiently storing ray traversal data |
US10699370B1 (en) | 2018-12-28 | 2020-06-30 | Intel Corporation | Apparatus and method for a compressed stack representation for hierarchical acceleration structures of arbitrary widths |
US12033238B2 (en) | 2020-09-24 | 2024-07-09 | Advanced Micro Devices, Inc. | Register compaction with early release |
CN114003363B (en) * | 2021-11-01 | 2022-07-22 | 支付宝(杭州)信息技术有限公司 | Method and device for sending interrupt signal between threads |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5579455A (en) * | 1993-07-30 | 1996-11-26 | Apple Computer, Inc. | Rendering of 3D scenes on a display using hierarchical z-buffer visibility |
US5933146A (en) * | 1994-12-01 | 1999-08-03 | Advanced Rendering Technology Limited | Method of and apparatus for constructing an image of a notional scene by a process of ray tracing |
US20020004710A1 (en) * | 2000-04-20 | 2002-01-10 | Ibm | Shape analysis system, difference detection system for three-dimensional model, similar shape search system, shape analysis method, difference detection method for three-dimensional model, siomilar shape search method, and storage medium and program transmission apparatus therefor |
US20020090141A1 (en) * | 1999-09-18 | 2002-07-11 | Kenyon Jeremy A. | Data compression through adaptive data size reduction |
US6429864B1 (en) * | 1999-11-10 | 2002-08-06 | Create.It Services Ag | Method for traversing a binary space partition or octree and image processor for implementing the method |
US6597359B1 (en) * | 2000-05-17 | 2003-07-22 | Raychip, Inc. | Hierarchical space subdivision hardware for ray tracing |
US20040125103A1 (en) * | 2000-02-25 | 2004-07-01 | Kaufman Arie E. | Apparatus and method for volume processing and rendering |
US6868420B2 (en) * | 2002-07-31 | 2005-03-15 | Mitsubishi Electric Research Laboratories, Inc. | Method for traversing quadtrees, octrees, and N-dimensional bi-trees |
US7012604B1 (en) * | 2002-09-12 | 2006-03-14 | Advanced Micro Devices, Inc. | System architecture for high speed ray tracing |
US20060066607A1 (en) * | 2002-08-26 | 2006-03-30 | Jorg Schmittler | Method and device for creating a two-dimensional representation of a three-dimensional structure |
US20060098009A1 (en) * | 2004-10-28 | 2006-05-11 | Miguel Zuniga | Method and apparatus for ray and range queries using wide object isolation techniques |
US20060139349A1 (en) * | 2004-12-28 | 2006-06-29 | Reshetov Alexander V | Applications of interval arithmetic for reduction of number of computations in ray tracing problems |
US20060149951A1 (en) * | 2004-12-15 | 2006-07-06 | International Business Machines Corporation | Method and apparatus for updating global branch history information |
US20070024615A1 (en) * | 2000-06-19 | 2007-02-01 | Alexander Keller | Real-time precision ray tracing |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69826539D1 (en) * | 1997-01-30 | 2004-11-04 | Sgs Thomson Microelectronics | Cache memory system |
US6205519B1 (en) * | 1998-05-27 | 2001-03-20 | Hewlett Packard Company | Cache management for a multi-threaded processor |
RU2215326C2 (en) * | 2001-06-29 | 2003-10-27 | Самсунг Электроникс Ко., Лтд. | Image-based hierarchic presentation of motionless and animated three-dimensional object, method and device for using this presentation to visualize the object |
US6654441B2 (en) * | 2001-08-02 | 2003-11-25 | Hitachi, Ltd. | Data processing method and data processing apparatus |
US6772179B2 (en) * | 2001-12-28 | 2004-08-03 | Lucent Technologies Inc. | System and method for improving index performance through prefetching |
US7536692B2 (en) * | 2003-11-06 | 2009-05-19 | Intel Corporation | Thread-based engine cache partitioning |
CN101213527A (en) * | 2005-06-29 | 2008-07-02 | 英特尔公司 | Method, device and system for caching |
-
2006
- 2006-07-28 US US11/460,797 patent/US20080024489A1/en not_active Abandoned
- 2006-12-07 US US11/567,882 patent/US7752413B2/en active Active
- 2006-12-07 US US11/567,874 patent/US7818503B2/en active Active
-
2007
- 2007-07-10 JP JP2009521198A patent/JP5043939B2/en not_active Expired - Fee Related
- 2007-07-10 EP EP07787323A patent/EP2070050A2/en not_active Withdrawn
- 2007-07-10 CN CN200780027168XA patent/CN101490715B/en not_active Expired - Fee Related
- 2007-07-10 WO PCT/EP2007/057048 patent/WO2008012199A2/en active Application Filing
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5579455A (en) * | 1993-07-30 | 1996-11-26 | Apple Computer, Inc. | Rendering of 3D scenes on a display using hierarchical z-buffer visibility |
US5933146A (en) * | 1994-12-01 | 1999-08-03 | Advanced Rendering Technology Limited | Method of and apparatus for constructing an image of a notional scene by a process of ray tracing |
US20020090141A1 (en) * | 1999-09-18 | 2002-07-11 | Kenyon Jeremy A. | Data compression through adaptive data size reduction |
US6429864B1 (en) * | 1999-11-10 | 2002-08-06 | Create.It Services Ag | Method for traversing a binary space partition or octree and image processor for implementing the method |
US20040125103A1 (en) * | 2000-02-25 | 2004-07-01 | Kaufman Arie E. | Apparatus and method for volume processing and rendering |
US20020004710A1 (en) * | 2000-04-20 | 2002-01-10 | Ibm | Shape analysis system, difference detection system for three-dimensional model, similar shape search system, shape analysis method, difference detection method for three-dimensional model, siomilar shape search method, and storage medium and program transmission apparatus therefor |
US6597359B1 (en) * | 2000-05-17 | 2003-07-22 | Raychip, Inc. | Hierarchical space subdivision hardware for ray tracing |
US20070024615A1 (en) * | 2000-06-19 | 2007-02-01 | Alexander Keller | Real-time precision ray tracing |
US6868420B2 (en) * | 2002-07-31 | 2005-03-15 | Mitsubishi Electric Research Laboratories, Inc. | Method for traversing quadtrees, octrees, and N-dimensional bi-trees |
US20060066607A1 (en) * | 2002-08-26 | 2006-03-30 | Jorg Schmittler | Method and device for creating a two-dimensional representation of a three-dimensional structure |
US7289118B2 (en) * | 2002-08-26 | 2007-10-30 | Universität des Saarlandes | Method and device for creating a two-dimensional representation of a three-dimensional structure |
US7012604B1 (en) * | 2002-09-12 | 2006-03-14 | Advanced Micro Devices, Inc. | System architecture for high speed ray tracing |
US20060098009A1 (en) * | 2004-10-28 | 2006-05-11 | Miguel Zuniga | Method and apparatus for ray and range queries using wide object isolation techniques |
US20060149951A1 (en) * | 2004-12-15 | 2006-07-06 | International Business Machines Corporation | Method and apparatus for updating global branch history information |
US20060139349A1 (en) * | 2004-12-28 | 2006-06-29 | Reshetov Alexander V | Applications of interval arithmetic for reduction of number of computations in ray tracing problems |
Cited By (77)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110050698A1 (en) * | 2006-09-19 | 2011-03-03 | Caustic Graphics, Inc. | Architectures for parallelized intersection testing and shading for ray-tracing rendering |
US9478062B2 (en) | 2006-09-19 | 2016-10-25 | Imagination Technologies Limited | Memory allocation in distributed memories for multiprocessing |
US9940687B2 (en) * | 2006-09-19 | 2018-04-10 | Imagination Technologies Limited | Dynamic graphics rendering scheduling |
US7830379B2 (en) | 2006-09-19 | 2010-11-09 | Caustic Graphics, Inc. | Architectures for parallelized intersection testing and shading for ray-tracing rendering |
US20090262132A1 (en) * | 2006-09-19 | 2009-10-22 | Caustic Graphics, Inc. | Architectures for parallelized intersection testing and shading for ray-tracing rendering |
US20090289939A1 (en) * | 2006-09-19 | 2009-11-26 | Caustic Graphics, Inc. | Systems and methods for concurrent ray tracing |
US20090322752A1 (en) * | 2006-09-19 | 2009-12-31 | Caustic Graphics, Inc. | Ray tracing system architectures and methods |
US8854369B2 (en) | 2006-09-19 | 2014-10-07 | Imagination Technologies, Limited | Systems and methods for concurrent ray tracing |
US8203559B2 (en) | 2006-09-19 | 2012-06-19 | Caustic Graphics, Inc. | Architectures for parallelized intersection testing and shading for ray-tracing rendering |
US9030476B2 (en) | 2006-09-19 | 2015-05-12 | Imagination Technologies, Limited | Dynamic graphics rendering scheduling |
US9665970B2 (en) | 2006-09-19 | 2017-05-30 | Imagination Technologies Limited | Variable-sized concurrent grouping for multiprocessing |
US20150242990A1 (en) * | 2006-09-19 | 2015-08-27 | Imagination Technologies Limited | Dynamic Graphics Rendering Scheduling |
US8203555B2 (en) | 2006-09-19 | 2012-06-19 | Caustic Graphics, Inc. | Systems and methods for concurrent ray tracing |
US8619079B2 (en) | 2006-09-19 | 2013-12-31 | Caustic Graphics, Inc. | Ray tracing system architectures and methods |
US7969434B2 (en) | 2006-09-19 | 2011-06-28 | Caustic Graphics, Inc. | Method, apparatus, and computer readable medium for accelerating intersection testing in ray-tracing rendering |
US8018457B2 (en) | 2006-09-19 | 2011-09-13 | Caustic Graphics, Inc. | Ray tracing system architectures and methods |
US7808500B2 (en) * | 2006-11-21 | 2010-10-05 | International Business Machines Corporation | Method for improving spatial index efficiency by jittering splitting planes |
US20080117206A1 (en) * | 2006-11-21 | 2008-05-22 | Robert Allen Shearer | Method for Improving Spatial Index Efficiency by Jittering Splitting Planes |
US7852336B2 (en) * | 2006-11-28 | 2010-12-14 | International Business Machines Corporation | Dynamic determination of optimal spatial index mapping to processor thread resources |
US20080122845A1 (en) * | 2006-11-28 | 2008-05-29 | Jeffrey Douglas Brown | Dynamic Determination of Optimal Spatial Index Mapping to Processor Thread Resources |
US20090096788A1 (en) * | 2007-10-12 | 2009-04-16 | Caustic Graphics, Inc. | Method and apparatus for increasing efficiency of transmission and/or storage of rays for parallelized ray intersection testing |
US8063902B2 (en) | 2007-10-12 | 2011-11-22 | Caustic Graphics, Inc. | Method and apparatus for increasing efficiency of transmission and/or storage of rays for parallelized ray intersection testing |
US20090128562A1 (en) * | 2007-11-19 | 2009-05-21 | Caustic Graphics, Inc. | Systems and methods for rendering with ray tracing |
US8237711B2 (en) | 2007-11-19 | 2012-08-07 | Caustic Graphics, Inc. | Tracing of shader-generated ray groups using coupled intersection testing |
US20130050213A1 (en) * | 2007-11-19 | 2013-02-28 | Caustic Graphics, Inc. | Systems and methods for rendering with ray tracing |
US8736610B2 (en) * | 2007-11-19 | 2014-05-27 | Imagination Technologies, Limited | Systems and methods for rendering with ray tracing |
US8502819B1 (en) * | 2007-12-17 | 2013-08-06 | Nvidia Corporation | System and method for performing ray tracing node traversal in image rendering |
US8212816B1 (en) * | 2007-12-17 | 2012-07-03 | Nvidia Corporation | System, method, and computer program product for parallel ray tracing traversal and intersection utilizing a single instruction multiple data (SIMD) processing architecture |
US8289324B1 (en) * | 2007-12-17 | 2012-10-16 | Nvidia Corporation | System, method, and computer program product for spatial hierarchy traversal |
US8253730B1 (en) * | 2008-08-29 | 2012-08-28 | Adobe Systems Incorporated | System and method for construction of data structures for ray tracing using bounding hierarchies |
US20100231589A1 (en) * | 2008-09-09 | 2010-09-16 | Caustic Graphics, Inc. | Ray tracing using ray-specific clipping |
US8421801B2 (en) | 2008-09-09 | 2013-04-16 | Caustic Graphics, Inc. | Ray tracing using ray-specific clipping |
US9911212B2 (en) * | 2009-02-24 | 2018-03-06 | International Business Machines Corporation | Resetting of dynamically grown accelerated data structure |
US20100228781A1 (en) * | 2009-02-24 | 2010-09-09 | International Business Machines Corporation | Resetting of Dynamically Grown Accelerated Data Structure |
US8669977B2 (en) * | 2009-10-01 | 2014-03-11 | Intel Corporation | Hierarchical mesh quantization that facilitates efficient ray tracing |
US20110080403A1 (en) * | 2009-10-01 | 2011-04-07 | Manfred Ernst | Memory efficient ray tracing with hierarchical mesh quantization |
US8629867B2 (en) | 2010-06-04 | 2014-01-14 | International Business Machines Corporation | Performing vector multiplication |
US20110304624A1 (en) * | 2010-06-14 | 2011-12-15 | Industry-Academic Cooperation Foundation Yonsei University | Method and apparatus for ray tracing in a 3-dimensional image system |
US9189882B2 (en) * | 2010-06-14 | 2015-11-17 | Samsung Electronics Co., Ltd. | Method and apparatus for ray tracing in a 3-dimensional image system |
US20110316855A1 (en) * | 2010-06-24 | 2011-12-29 | International Business Machines Corporation | Parallelized Streaming Accelerated Data Structure Generation |
US8692825B2 (en) * | 2010-06-24 | 2014-04-08 | International Business Machines Corporation | Parallelized streaming accelerated data structure generation |
US20120050289A1 (en) * | 2010-08-26 | 2012-03-01 | Industry-Academic Cooperation Foundation, Yonsei Universtiy | Image processing apparatus and method |
US9355491B2 (en) * | 2010-08-26 | 2016-05-31 | Samsung Electronics Co., Ltd. | Ray tracing apparatus and method |
KR20120019720A (en) * | 2010-08-26 | 2012-03-07 | 삼성전자주식회사 | Image processing apparatus and method |
KR101697238B1 (en) * | 2010-08-26 | 2017-01-17 | 삼성전자주식회사 | Image processing apparatus and method |
US8791945B2 (en) * | 2011-05-18 | 2014-07-29 | Intel Corporation | Rendering tessellated geometry with motion and defocus blur |
US9965892B2 (en) | 2011-05-18 | 2018-05-08 | Intel Corporation | Rendering tessellated geometry with motion and defocus blur |
US20120293515A1 (en) * | 2011-05-18 | 2012-11-22 | Clarberg Franz P | Rendering Tessellated Geometry With Motion and Defocus Blur |
US10061618B2 (en) | 2011-06-16 | 2018-08-28 | Imagination Technologies Limited | Scheduling heterogenous computation on multithreaded processors |
US8692834B2 (en) | 2011-06-16 | 2014-04-08 | Caustic Graphics, Inc. | Graphics processor with non-blocking concurrent architecture |
US9367949B2 (en) | 2012-09-17 | 2016-06-14 | Samsung Electronics Co., Ltd. | Apparatus and method for scheduling of ray tracing |
US9728000B2 (en) * | 2013-10-22 | 2017-08-08 | Samsung Electronics Co., Ltd. | Apparatus and method of using acceleration structure in ray tracing |
US20150109301A1 (en) * | 2013-10-22 | 2015-04-23 | Samsung Electronics Co., Ltd. | Apparatus and method of using acceleration structure in ray tracing |
US9996966B2 (en) | 2013-11-04 | 2018-06-12 | Samsung Electronics Co., Ltd. | Ray tracing method and apparatus |
US9495792B2 (en) * | 2013-11-20 | 2016-11-15 | Samsung Electronics Co., Ltd. | Method and apparatus for traversing binary tree in ray tracing system |
US20150138202A1 (en) * | 2013-11-20 | 2015-05-21 | Samsung Electronics Co., Ltd. | Method and apparatus for traversing binary tree in ray tracing system |
US9619923B2 (en) | 2014-01-14 | 2017-04-11 | Raycast Systems, Inc. | Computer hardware architecture and data structures for encoders to support incoherent ray traversal |
US9035946B1 (en) | 2014-02-13 | 2015-05-19 | Raycast Systems, Inc. | Computer hardware architecture and data structures for triangle binning to support incoherent ray traversal |
US9087394B1 (en) | 2014-02-13 | 2015-07-21 | Raycast Systems, Inc. | Computer hardware architecture and data structures for packet binning to support incoherent ray traversal |
US8947447B1 (en) | 2014-02-13 | 2015-02-03 | Raycast Systems, Inc. | Computer hardware architecture and data structures for ray binning to support incoherent ray traversal |
US9761040B2 (en) | 2014-02-13 | 2017-09-12 | Raycast Systems, Inc. | Computer hardware architecture and data structures for ray binning to support incoherent ray traversal |
US8928675B1 (en) | 2014-02-13 | 2015-01-06 | Raycast Systems, Inc. | Computer hardware architecture and data structures for encoders to support incoherent ray traversal |
US9058691B1 (en) * | 2014-02-13 | 2015-06-16 | Raycast Systems, Inc. | Computer hardware architecture and data structures for a ray traversal unit to support incoherent ray traversal |
US8952963B1 (en) | 2014-02-13 | 2015-02-10 | Raycast Systems, Inc. | Computer hardware architecture and data structures for a grid traversal unit to support incoherent ray traversal |
US10019830B2 (en) | 2014-04-02 | 2018-07-10 | Samsung Electronics Co., Ltd. | Method and apparatus for rendering same regions of multi frames |
US9697640B2 (en) | 2014-04-21 | 2017-07-04 | Qualcomm Incorporated | Start node determination for tree traversal in ray tracing applications |
US20170061673A1 (en) * | 2015-08-31 | 2017-03-02 | Samsung Electronics Co., Ltd. | Method of generating and traversing acceleration structure |
US10019832B2 (en) * | 2015-08-31 | 2018-07-10 | Samsung Electronics Co., Ltd. | Method of generating and traversing acceleration structure |
US20170091898A1 (en) * | 2015-09-24 | 2017-03-30 | Samsung Electronics Co., Ltd. | Apparatus for and method of traversing tree |
US9818221B2 (en) | 2016-02-25 | 2017-11-14 | Qualcomm Incorporated | Start node determination for tree traversal for shadow rays in graphics processing |
US10319139B2 (en) * | 2017-04-01 | 2019-06-11 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US10776986B2 (en) * | 2017-04-01 | 2020-09-15 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US11074741B2 (en) | 2017-04-01 | 2021-07-27 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US11580686B2 (en) | 2017-04-01 | 2023-02-14 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US11935178B2 (en) | 2017-04-01 | 2024-03-19 | Intel Corporation | Apparatus and method for data-parallel ray tracing using volume proxies |
US12118398B2 (en) | 2018-07-20 | 2024-10-15 | Imagination Technologies Limited | Scheduling heterogeneous computation on multithreaded processors |
US11238640B2 (en) * | 2020-06-26 | 2022-02-01 | Advanced Micro Devices, Inc. | Early culling for ray tracing |
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US7818503B2 (en) | 2010-10-19 |
US7752413B2 (en) | 2010-07-06 |
WO2008012199A2 (en) | 2008-01-31 |
JP2009545044A (en) | 2009-12-17 |
US20080028154A1 (en) | 2008-01-31 |
EP2070050A2 (en) | 2009-06-17 |
JP5043939B2 (en) | 2012-10-10 |
CN101490715A (en) | 2009-07-22 |
US20080028403A1 (en) | 2008-01-31 |
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