WO2016027912A1

WO2016027912A1 - Ray tracing method, ray tracing apparatus for performing same, and recording medium for storing same

Info

Publication number: WO2016027912A1
Application number: PCT/KR2014/007695
Authority: WO
Inventors: 김진우; 정우남; 이민우
Original assignee: 주식회사 실리콘아츠
Priority date: 2014-08-19
Filing date: 2014-08-19
Publication date: 2016-02-25

Abstract

The present invention relates to a ray tracing method comprising the steps of: generating multiple first sub-scenes by performing a space division of a scene according to a first reference; performing ray tracing with respect to the multiple first sub-scenes; and generating multiple second sub-scenes by re-performing the space division with respect to the scene according to a second reference when computational complexity for the ray tracing exceeds a particular reference. Therefore, the present invention can reduce a total performance time by performing ray tracing at the same time as when generating a tree.

Description

Ray tracing method, ray tracing device for performing the same and a recording medium storing the same

The present invention relates to a ray tracing technology, and more particularly, to a ray tracing method that can shorten the overall execution time by performing a ray tracing at the time of tree generation, a ray tracing apparatus for performing the same and a recording medium for storing the same will be.

Three-dimensional graphics technology is a graphics technology that uses a three-dimensional representation of geometric data stored in computing, and is widely used in various industries today, including the media industry and the game industry. In general, three-dimensional graphics technology requires a separate high performance graphics processor due to the large amount of computation. In particular, a ray tracing technique that can generate realistic three-dimensional graphics according to recent developments of processors has been studied.

Ray tracing technology is a rendering method based on global illumination, and the reflection, refraction, and shadow effects are natural in consideration of the influence of light reflected or refracted by another object on the current object image. 3D image can be generated realistically.

Korean Patent No. 10-1284324 discloses a ray tracing core and a ray tracing method capable of accelerating displacement mapping. Such a technique determines a start level by performing a bit operation set at a start point and an end point on a ray defined as a start point and an end point, and selectively increases the level by checking node crossing for the determined start level. In this way, the search time of the pyramid displacement map can be reduced and a realistic scene can be generated.

Korean Laid-Open Patent Publication No. 10-2014-0013292 discloses a ray tracing calculation system configured to calculate ray tracing for generating a three-dimensional image in which an optical effect is reflected. This technique can reduce the size of the ray tracing unit and increase the utilization of the graphics processing unit, thereby reducing the cost of building the ray tracing calculation system.

One embodiment of the present invention is to provide a ray tracing method that can shorten the overall execution time by performing ray tracing at the time of tree generation.

An embodiment of the present invention is to provide a ray tracing method that can improve the quality of the tree by updating the tree according to the computational complexity of ray tracing.

An embodiment of the present invention is to provide a ray tracing method that can accelerate the performance of ray tracing according to the improvement of the quality of the tree.

Among the embodiments, the ray tracing method may include generating a plurality of first sub-scenes by performing spatial division on a scene according to a first criterion, performing ray tracing on the plurality of first sub-scenes, and If the computational complexity for the ray tracing exceeds a specific criterion, re-segmenting the space for the scene according to a second criterion to generate a plurality of second sub-scenes.

In an embodiment, the generating of the plurality of first sub-scenes may include performing spatial division on the scene based on one of a central division, a median division, and a search division.

The generating of the plurality of first sub-scenes may include generating a first reference tree associated with an internal node of an acceleration structure (AS) through the spatial division.

Generating the plurality of first sub-scenes may include inserting primitive nodes associated with the plurality of first sub-scenes into the first reference tree to generate the acceleration structure.

In one embodiment, performing ray tracing may include performing ray tracing of the scene based on the generated acceleration structure when insertion of the primitive nodes is completed.

In one embodiment, generating the plurality of second sub-scenes may include adjusting a first reference tree in the generated acceleration structure based on the amount of computation and computation time for the ray tracing.

The generating of the plurality of second sub-scenes may include performing a re-segmentation of the space based on the one other than the first criterion among the center division, the median division, and the search division.

The generating of the plurality of second sub-scenes may include generating a second reference tree associated with an internal node of an acceleration structure (AS) through the spatial division.

Generating the plurality of second sub-scenes may include inserting primitive nodes associated with the plurality of second sub-scenes into the second reference tree to generate the acceleration structure.

In an embodiment, the method may include performing ray tracing on the scene based on the generated acceleration structure in the insertion of the primitive nodes.

In an embodiment, the method may include repeating a process of performing ray tracing on the scene based on an acceleration structure associated with the reference tree until the computational complexity of the ray tracing does not exceed a specific criterion.

Among the embodiments, the ray tracing apparatus may perform a segmentation on a scene according to a first criterion to generate a plurality of first sub-scenes and a ray tracing of the plurality of first sub-scenes. And a ray tracing performing unit configured to generate a plurality of second sub-scenes by performing spatial segmentation on the scene according to a second criterion when the computational complexity of the ray tracing exceeds a specific criterion. It features.

In one or more embodiments, a computer-readable recording medium having a program for implementing a ray tracing method recorded thereon may be configured to generate a plurality of first sub-scenes by performing spatial division on a scene according to a first criterion. A function of performing ray tracing on the first sub-scenes of the at least one sub-scene, and performing a segmentation on the scene according to a second criterion if the computational complexity of the ray tracing exceeds a specific criterion to generate a plurality of second sub-scenes. It includes the function to do it.

The ray tracing method according to an embodiment of the present invention may shorten the overall execution time by simultaneously performing ray tracing during tree generation.

The ray tracing method according to an embodiment of the present invention may improve the quality of the tree by updating the tree according to the computational complexity of ray tracing.

Ray tracing method according to an embodiment of the present invention can accelerate the performance of the ray tracing according to the improvement of the quality of the tree.

1 is a block diagram illustrating a ray tracing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a ray tracing process performed by the ray tracing apparatus of FIG. 1.

FIG. 3 is a diagram illustrating a criterion of space division for a scene performed in the ray tracing apparatus of FIG. 1.

FIG. 4 is a diagram illustrating a reference tree generated by the ray tracing apparatus of FIG. 1.

FIG. 5 is a graph illustrating a relationship between quality of a sub-scene according to ray tracing performed in the ray tracing apparatus of FIG. 1.

Description of the present invention is only an embodiment for structural or functional description, the scope of the present invention should not be construed as limited by the embodiments described in the text. That is, since the embodiments may be variously modified and may have various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical idea. In addition, the objects or effects presented in the present invention does not mean that a specific embodiment should include all or only such effects, the scope of the present invention should not be understood as being limited thereby.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

Terms such as "first" and "second" are intended to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, the first component may be named a second component, and similarly, the second component may also be named a first component.

When a component is referred to as being "connected" to another component, it should be understood that there may be other components in between, although it may be directly connected to the other component. On the other hand, when a component is referred to as being "directly connected" to another component, it should be understood that there is no other component in between. On the other hand, other expressions describing the relationship between the components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring to", should be interpreted as well.

Singular expressions should be understood to include plural expressions unless the context clearly indicates otherwise, and terms such as "comprise" or "have" refer to a feature, number, step, operation, component, part, or feature thereof. It is to be understood that the combination is intended to be present and does not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, operations, components, parts or combinations thereof.

In each step, an identification code (e.g., a, b, c, etc.) is used for convenience of description, and the identification code does not describe the order of the steps, and each step clearly indicates a specific order in context. Unless stated otherwise, they may occur out of the order noted. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

The present invention can be embodied as computer readable code on a computer readable recording medium, and the computer readable recording medium includes all kinds of recording devices in which data can be read by a computer system. . Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like, and are also implemented in the form of a carrier wave (for example, transmission over the Internet). It also includes. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. Generally, the terms defined in the dictionary used are to be interpreted to coincide with the meanings in the context of the related art, and should not be interpreted as having ideal or excessively formal meanings unless clearly defined in the present application.

The present invention was carried out from September 1, 2013 to August 31, 2014 at Silicon Arts Co., Ltd. with the support of Seoul Patents Industry Development Institute, Patent Technology Commercialization Technology Development Support Project, Seoul, Korea. Development of Software Kit for Development "(Task No. PA130017).

Referring to FIG. 1, the ray tracing apparatus 100 includes a sub scene generation unit 110, a ray tracing performing unit 120, and a controller 130.

The sub scene generation unit 110 generates a plurality of first sub scenes by performing spatial division on the scene according to the first criterion. The first criterion may be determined as one of a central partition, a median partition, and a search partition. The central partition is to divide at the center of the space, the median partition is to divide around the middle of the plurality of objects constituting the scene, and the search partition is to split based on the search cost of the reference tree. . Hereinafter, center division, median division, and search division will be described in detail with reference to FIG. 3. The plurality of first sub-scenes may each include one entity constituting the scene.

The sub-scene generation unit 110 may determine one of the center division, the median division, and the search division except for the first criterion as the second criterion, and re-segment the space for the scene based on the second criterion. Here, when the computational complexity of ray tracing exceeds a specific criterion, the sub-scene generator 110 may re-segment the space for the scene.

The sub-scene generator 110 may generate a first reference tree associated with an internal node of an acceleration structure (AS) through spatial division of the scene. The acceleration structure includes a k-depth tree (kd-tree) or a bounding volume hierarchy (BVH) commonly used in ray tracing.

In the present invention, it is assumed that the acceleration structure uses BVH. The BVH includes a box node, an inner node, and a leaf node, and the leaf node includes a triangle list for pointing at least one triangle information included in the geometric data. The geometric data includes information about a triangle for ray tracing (hereinafter referred to as triangle information). For example, the triangle information may include texture coordinates and normal vectors for three triangle points. In one embodiment, the first reference tree may be implemented as a binary tree capable of hierarchical parallelism. For example, at least one node may be arranged such that the first reference tree corresponds to each level (eg, box node corresponds to level 0, internal node corresponds to level 1 to N-1, and leaf node corresponds to level N). Can be.

The sub-scene generator 110 may generate an acceleration structure by inserting primitive nodes associated with the plurality of first sub-scenes into the first reference tree. Primitive nodes may be classified to the left or right of the inner node along the first reference tree and passed to the leaf node.

The sub scene generation unit 110 may calculate a computational complexity for ray tracing when ray tracing of the plurality of first sub scenes is performed. The computation complexity may be calculated based on the amount of computation and the computation time. For example, the computation complexity may increase as the computation amount increases and the computation time increases. The sub scene generation unit 110 may adjust the first reference tree in the acceleration structure based on the calculation amount and the calculation time for ray tracing. That is, the sub-scene generation unit 110 re-spatially divides the scene according to a second criterion (the second criterion corresponds to one except the first criterion among the center division, the median division, and the search division). Sub-scenes may be generated, and a second reference tree associated with an internal node of the acceleration structure may be generated through spatial partitioning of the scene.

The sub-scene generator 110 may generate an acceleration structure by inserting primitive nodes associated with the plurality of second sub-scenes into the second reference tree.

The sub-scene generator 110 generates a reference tree associated with the internal node of the acceleration structure based on the plurality of sub-scenes generated by spatial division of the scene until the computational complexity for ray tracing does not exceed a specific criterion. Primitive nodes associated with a plurality of sub-scenes may be inserted into a reference tree to generate an acceleration structure.

The ray tracing performing unit 120 performs ray tracing on the plurality of first sub-scenes. In one embodiment, the ray tracing performing unit 120 may perform ray tracing on the scene based on the acceleration structure associated with the first reference tree when insertion of the primitive nodes is completed.

The ray tracing performing unit 120 performs ray tracing on the plurality of second sub-scenes. In an embodiment, the ray tracing performing unit 120 may perform ray tracing on the scene based on the acceleration structure associated with the second reference tree during the insertion of the primitive nodes.

The ray tracing performing unit 120 may repeat the process of performing ray tracing on the scene based on the acceleration structure associated with the reference tree until the computational complexity of the ray tracing does not exceed a specific criterion.

The controller 130 may control the overall operation of the ray tracing apparatus 100 and may control a control flow or data flow between the sub-scene generator 110 and the ray tracing performer 120.

Referring to FIG. 2, the sub scene generation unit 110 performs spatial division on a scene according to a specific criterion (step S201).

In one embodiment, the particular criterion may be determined as one of a central partition, a median partition, and a search partition.

The sub-scene generator 110 generates a reference tree associated with an internal node of an acceleration structure (AS) through spatial division of a scene, and inserts primitive nodes associated with a plurality of sub-scenes into a reference tree to accelerate the scene. You can create a structure.

The ray tracing performing unit 120 performs ray tracing on the plurality of sub-scenes (step S202).

The ray tracing performing unit 120 performs ray tracing after the insertion of the primitive nodes is completed if ray tracing is the first, and ray tracing during the insertion process of the primitive nodes if the ray tracing is not the first. Can be performed.

When the ray tracing for the plurality of sub-scenes is performed, the sub scene generation unit 110 determines a computational complexity for ray tracing (step S203).

The sub-scene generation unit 110 changes a specific criterion of spatial division for the scene (in which the specific criterion corresponds to a criterion different from the specific criterion of step S201) when the computational complexity for ray tracing exceeds a specific criterion ( Steps S204 and S205).

The sub scene generation unit 110 repeats the above steps until the computational complexity for ray tracing does not exceed a specific criterion.

Referring to FIG. 3, the sub-scene generation unit 110 determines one of the center division (a), the median division (b), and the search division (c) based on the scene determined based on the one determined based on the spatial division of the scene. Space partitioning can be performed.

Split in the Middle (a) is to divide a scene in the center of the space, and the split can be performed faster than other splits, but it can inefficiently generate an acceleration structure. Split at the Median (b) splits a scene around an object in the intermediate order of a plurality of objects constituting the scene, and can perform a sort operation and create a balanced tree. . Cost-Optimized Split (c) divides a scene according to a search cost of a reference tree, and can generate a tree in consideration of its position and size and efficiently generate an acceleration structure.

In one embodiment, the search cost (Cost-Optimized Split) (c) may be determined based on the probability of visiting the internal node of the acceleration structure. For example, the search cost may be determined according to the following equation.

[Equation]

Here, KT and KI correspond to constants, SA (VL) corresponds to the left surface area of the acceleration structure, SA (VR) corresponds to the right surface area of the acceleration structure, and SA (V ) Corresponds to the total surface area of the acceleration structure, and NL and NR correspond to the number of left and right nodes, respectively.

Referring to FIG. 4A, the sub-scene generation unit 110 includes an internal node 410 of an acceleration structure (AS) through spatial division of a scene (here, the internal node includes a box node and a leaf node). And a first reference tree associated with it). The first reference tree may be adjusted to the second reference tree (or Nth reference tree) according to the computational complexity for ray tracing.

Referring to FIG. 4B, the sub-scene generator 110 may generate an acceleration structure by inserting primitive nodes associated with the plurality of first sub-scenes into the first reference tree. Primitive nodes may be stored in the primitive node list, output sequentially (eg, in the form of a queue algorithm), and inserted into the first reference tree.

The sub scene generation unit 110 may insert the initialization node 420 to initialize the first reference tree before inserting the primitive nodes into the first reference tree. When the first reference tree is sequentially initialized, the sub-scene generator 110 may sequentially insert the primitive nodes 430 to deliver the primitive nodes 430 to the last (ie, leaf nodes) of the internal nodes. The sub-scene generator 110 may generate an acceleration structure by passing the primitive node 430 to the last of the internal node.

Referring to FIG. 5, the ray tracing apparatus 100 generates a plurality of first sub-scenes by performing spatial division on a scene according to a first criterion in the sub-scene generating unit 110 and is associated with an internal node of an acceleration structure. When the first reference tree is generated and the acceleration structure is generated, the first graph tree has the same quality as the first graph 510. After the first reference tree is generated, the Nth reference tree is generated (where N is a natural number). It may have the same quality as the three

graphs

520 and 530. This means that each reference tree is implemented independently.

Although described above with reference to the preferred embodiment of the present application, those skilled in the art various modifications and changes to the present application without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims

Generating a plurality of first sub-scenes by performing spatial division on the scene according to the first criterion;

Performing ray tracing on the plurality of first sub-scenes; And

If the computational complexity for ray tracing exceeds a specific criterion, re-segmenting the spatial segmentation for the scene according to a second criterion to generate a plurality of second sub-scenes.
The method of claim 1, wherein the generating of the plurality of first sub-scenes comprises:

And performing spatial segmentation on the scene based on one of center segmentation, median segmentation, and search segmentation.
The method of claim 1, wherein the generating of the plurality of first sub-scenes comprises:

And generating a first reference tree associated with an internal node of an acceleration structure (AS) through the spatial partitioning.
The method of claim 3, wherein the generating of the plurality of first sub-scenes comprises:

Inserting primitive nodes associated with the plurality of first sub-scenes into the first reference tree to generate the acceleration structure.
The method of claim 4, wherein performing ray tracing

And performing ray tracing on the scene based on the generated acceleration structure when insertions of the primitive nodes are completed.
The method of claim 4, wherein the generating of the plurality of second sub-scenes comprises:

And adjusting a first reference tree in the generated acceleration structure based on the amount of computation and the computation time for the ray tracing.
The method of claim 1, wherein the generating of the plurality of second sub-scenes comprises:

And re-segmenting the spatial segmentation for the scene based on one of the center segment, the median segmentation, and the search segment except the first criterion.
The method of claim 7, wherein generating the plurality of second sub-scenes

And generating a second reference tree associated with an internal node of an acceleration structure (AS) through the spatial partitioning.
The method of claim 8, wherein the generating of the plurality of second sub-scenes comprises:

Inserting primitive nodes associated with the plurality of second sub-scenes into the second reference tree to generate the acceleration structure.
The method of claim 9,

And performing ray tracing on the scene based on the generated acceleration structure during insertion of the primitive nodes.
The method of claim 1,

Repeating the process of performing ray tracing on the scene based on the acceleration structure associated with the reference tree until the computational complexity for the ray tracing does not exceed a particular criterion.
A sub-scene generator for generating a plurality of first sub-scenes by performing spatial division on a scene according to a first criterion; And

A ray tracing performing unit configured to perform ray tracing on the plurality of first sub-scenes,

The sub scene generation unit

And if the computational complexity of the ray tracing exceeds a specific criterion, re-segment the spatial segmentation of the scene according to a second criterion to generate a plurality of second sub-scenes.
Generating a plurality of first sub-scenes by performing spatial division on a scene according to a first criterion;

Performing ray tracing on the plurality of first sub-scenes; And

A program for implementing a ray tracing method including a function of generating a plurality of second sub-scenes by performing spatial division on the scene according to a second criterion when the computational complexity of the ray tracing exceeds a specific criterion; Computer-readable recording media.