JP2011209865A - Program, information storage medium, and image creation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a program, an information storage medium and an image creation system for reproducing blurring due to the depth of field with a relatively light plotting load with respect to a particle.SOLUTION: A given particle is created at a given position in an object space, and the distance information of the direction of a line of sight of a virtual camera between the virtual camera and the particle is calculated, and the amount of blurring corresponding to the position of the particle is calculated, and whether the position of the particle is present within a given blurring object range is determined based on the distance information, and when the position of the particle is present within the blurring object range, the blurring image of the particle corresponding to the amount of blurring is created.

Description

  The present invention relates to a program, an information storage medium, and an image generation system.

  Conventionally, an image generation system (game system) that generates an image that can be viewed from a virtual camera (a given viewpoint) in an object space (virtual three-dimensional space) in which an object such as a character is set is known. It is popular as a place to experience so-called virtual reality.

  In such an image generation system (game system), there is a case where an image in which blurring due to the depth of field of the camera is reproduced is generated aiming at a visually high effect. One commonly used technique for expressing depth of field is post-effect processing for the entire screen. This method uses depth information that is simultaneously written in a depth buffer (Z buffer) when a 3D model is drawn in a color buffer, determines a blur amount for pixels that are out of the depth of field, and blurs the image on the entire screen. Is generated.

Japanese Patent Laid-Open No. 2003-51024

  By the way, when drawing petals, snow, rain, smoke, flames, etc., in order to realize a realistic image with a relatively light processing load, these may be expressed by translucent particles. When an image including these particles is generated, in many cases, depth information is not written in the depth buffer (Z buffer) for each pixel of the particle so that the drawing process is not complicated. Therefore, when reproducing the blur due to the depth of field with respect to an image including particles, if the conventional method is applied as it is, the particles are blurred by referring to the depth information of the object behind it. For example, in the image shown in FIG. 12, since the center building is at the depth of field of the virtual camera, the petals P (particles) in front of the building are not blurred in the upper left part overlapping the building. The lower right part that overlaps with is blurred with the background, making the image uncomfortable.

  It may not be impossible to write depth information for particles and reproduce the blur due to depth of field using conventional methods, but for example, it depends on depth of field only for particles, not for full screen. Even when it is desired to reproduce the blur, there is a problem that the drawing load increases because it is necessary to refer to a depth buffer having the same size as the entire screen.

  The present invention has been made in view of the above problems, and according to some aspects of the present invention, it is possible to reproduce the blur due to the depth of field with a relatively light drawing load on the particles. Possible programs, information storage media, and image generation systems can be provided.

(1) The present invention
A program for generating an image visible from a virtual camera in an object space,
A particle generator for generating a given particle at a given position in the object space;
A distance information calculation unit that calculates distance information of the virtual camera and the particles in the viewing direction of the virtual camera;
A blur amount calculation unit for calculating a blur amount according to the position of the particle;
Based on the distance information, it is determined whether the position of the particle is within a given blurring target range, and if it is within the blurring target range, a blur image of the particle corresponding to the blur amount is generated. A computer is caused to function as a blurred image generation unit.

  The present invention also relates to an information storage medium that can be read by a computer and stores a program that causes the computer to function as each of the above-described units. The present invention also relates to an image generation system including the above-described units.

  In the present invention, the distance information in the viewing direction of the virtual camera and the particle between the virtual camera and the particle is calculated, and the blurred image of the particle is generated based on the distance information. Therefore, the depth information is stored in the depth buffer (Z buffer) for the particle. There is no need to write. Therefore, according to the present invention, it is possible to reproduce the blur due to the depth of field with a relatively light drawing load for the particles.

(2) In the program, information storage medium, and image generation system according to the present invention,
The computer further functions as a particle size changing unit that enlarges or reduces the particles according to the blur amount (including a particle size changing unit),
The blurred image generation unit
You may make it produce | generate the said blurring image according to the said blurring amount with respect to the said particle after enlarging or reducing.

  According to the present invention, by appropriately adjusting the particle size according to the amount of blurring, it is possible to perform drawing processing on particles as small as possible including the drawing region of the blurred image. . Thereby, the drawing load of the blurred image can be reduced.

(3) In the program, the information storage medium, and the image generation system according to the present invention,
The blur amount calculation unit
As the blur amount, a blur amount corresponding to the distance between the virtual camera and the particles in the visual line direction of the virtual camera may be calculated.

(4) In the program, the information storage medium, and the image generation system according to the present invention,
The blur amount calculation unit
As the blur amount, a blur amount corresponding to a linear distance between the virtual camera and the particles may be calculated.

(5) In the program, the information storage medium, and the image generation system according to the present invention,
The computer includes a main processor and a drawing processor;
The computer is further caused to function as a blurring process assignment control unit that controls which of the processing of the distance information calculation unit, the blurred image generation unit, and the particle size changing unit is assigned to the main processor or the drawing processor (blurring process). An allocation control unit may be further included).

(6) In the program, the information storage medium, and the image generation system according to the present invention,
The blur processing assignment control unit
Based on the current allocation status of each process and the current processing load of each of the main processor and the rendering processor, it is controlled whether the process is allocated to the main processor or the rendering processor. It may be.

  According to the present invention, the allocation of the distance information calculation process, the particle size change process, and the blurred image generation process can be dynamically changed according to the processing load of the main processor and the processing load of the drawing processor. Blur processing can be performed.

(7) In the program, the information storage medium, and the image generation system according to the present invention,
The blur processing assignment control unit
Depending on the number or total area of the particles to be drawn, it may be controlled which of the processing is assigned to the main processor or the drawing processor.

  According to the present invention, since the processing load of the main processor and the drawing processor can be changed according to the number of particles and the total area, blurring can be performed efficiently.

The figure which shows an example of the functional block diagram of the image generation system (game system) of this embodiment. The figure which shows an example of the image produced | generated by the method of this embodiment. The figure for demonstrating a particle. The figure for demonstrating an example of the blurring object range and the blurring amount. The figure for demonstrating another example of the blurring object range and the blurring amount. The figure for demonstrating the image generation of the particle by this embodiment. The flowchart figure of an example of the blurring process of this embodiment. The figure which shows an example of the allocation pattern of a blurring process. The flowchart figure of an example of the control which changes the allocation pattern of a blurring process dynamically. The flowchart figure of another example of the control which changes the allocation pattern of a blurring process dynamically. The figure which shows the example of the hardware constitutions which can implement | achieve this embodiment. The figure which shows an example of the image produced | generated by the conventional method.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. Configuration FIG. 1 shows an example of a functional block diagram of an image generation system (game system) of the present embodiment. Note that the image generation system of the present embodiment may have a configuration in which some of the components (each unit) in FIG. 1 are omitted.

  The operation unit 160 is for a player to input operation data of an object (player character, moving object), and its function can be realized by a lever, a button, a steering, a microphone, a touch panel type display, or a casing.

  Note that the operation unit 160 may be one that can input input data (operation data) from a player by an input device that includes an acceleration sensor, an imaging unit, or a gyro sensor that detects angular velocity. For example, the input device may be one that the player holds and moves, or that the player wears and moves. The input device also includes a controller simulating an actual tool such as a sword-type controller or gun-type controller held by the player, or a glove-type controller worn by the player (attached to the hand of the player). It is. The input device includes a game device integrated with the input device, a portable game device, a mobile phone, and the like.

  For example, an acceleration sensor provided in an input device detects acceleration in three axes (X axis, Y axis, and Z axis). That is, the acceleration sensor can detect acceleration in the vertical direction, the horizontal direction, and the front-rear direction. The acceleration sensor detects acceleration every 5 msec. Further, the acceleration sensor may detect a uniaxial, biaxial, or six-axis acceleration. The acceleration detected from the acceleration sensor is transmitted to the game device (main device) by the communication unit of the input device.

  The imaging unit provided in the input device includes an infrared filter, a lens, an imaging device (image sensor), and an image processing circuit. The infrared filter is disposed in front of the input device and allows only infrared light to pass through from light incident from a light source disposed in association with the display unit 190. The lens condenses the infrared light transmitted through the infrared filter and emits it to the image sensor. The image pickup device is a solid-state image pickup device such as a CMOS sensor or a CCD, for example, and picks up infrared light collected by the lens to generate a picked-up image. A captured image generated by the image sensor is processed by an image processing circuit. For example, the captured image obtained from the image sensor is processed to detect a high-luminance portion, and the position information (specific position) of the light source in the captured image is detected. If there are a plurality of light sources, position information on the captured image is detected. Further, the detected position information on the captured image is transmitted to the main device by the communication unit.

  The storage unit 170 serves as a work area for the processing unit 100, the communication unit 196, and the like, and its function can be realized by a RAM (VRAM) or the like. The storage unit 170 includes a main storage unit 172 that is used as a work area, a drawing buffer 174 that stores final display images, an object data storage unit 176 that stores model data of objects, and each object. A texture storage unit 178 that stores the associated texture and a Z buffer 179 that stores the Z value during the object generation process are included. Note that some of these may be omitted.

  The information storage medium 180 (computer-readable medium) stores programs, data, and the like, and functions as an optical disk (CD, DVD), magneto-optical disk (MO), magnetic disk, hard disk, and magnetic tape. Alternatively, it can be realized by a memory (ROM). The processing unit 100 performs various processes of the present embodiment based on a program (data) stored in the information storage medium 180. The information storage medium 180 can store a program for causing a computer to function as each unit of the present embodiment (a program for causing a computer to execute processing of each unit).

  The display unit 190 outputs an image generated according to the present embodiment, and its function can be realized by a CRT, LCD, touch panel display, HMD (head mounted display), or the like. The sound output unit 192 outputs the sound generated by the present embodiment, and its function can be realized by a speaker, headphones, or the like.

  The communication unit 196 performs various controls for communicating with the outside (for example, another image generation system), and the function is realized by various processors or hardware such as a communication ASIC, a program, or the like. it can.

  Note that a program or data for causing a computer to function as each unit of the present embodiment stored in the information storage medium or storage unit of the server is received via the network, and the received program or data is received by the information storage medium 180. Or may be stored in the storage unit 170. The case where the program or data is received and the image generation system is made to function is also included in the scope of the present invention.

  The processing unit 100 (processor) performs processing such as game processing, image generation processing, or sound generation processing based on operation data and programs from the operation unit 160. Here, as the game process, a process for starting a game when a game start condition is satisfied, a process for advancing the game, a process for placing an object such as a character or a map, a process for displaying an object, and a game result are calculated. There is a process or a process of ending a game when a game end condition is satisfied.

  The processing unit 100 performs various processes using the main storage unit 172 in the storage unit 170 as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs.

  In particular, in this embodiment, part of the functions of the processing unit 100 is realized by a main processor (CPU) and a drawing processor (GPU).

  The processing unit 100 includes an object space setting unit 110, a movement / motion processing unit 112, a virtual camera control unit 114, a drawing unit 120, and a sound generation unit 130. Note that some of these may be omitted.

  In particular, in the present embodiment, the processing unit 100 includes a blurring process assignment control unit 116. The blurring process assignment control unit 116 controls whether each process of the distance information calculation unit 124, the blurry image generation unit 129, and the particle size changing unit 128 is assigned to the main processor or the drawing processor. For example, the blurring process allocation control unit 116 includes the current allocation status of each process of the distance information calculation unit 124, the blur image generation unit 129, and the particle size changing unit 128, and the current processing loads of the main processor and the drawing processor. Based on the above, it may be controlled which of the processing is assigned to the main processor or the drawing processor. In addition, for example, the blurring process assignment control unit 116 performs each process of the distance information calculation unit 124, the blurred image generation unit 129, and the particle size changing unit 128 as a main processor according to the number or total area of particles to be rendered. You may make it control which drawing processor allocates.

  The object space setting unit 110 includes various objects (lines, line polygons, polygons, polygons) representing display objects such as snow, rain, characters, buildings, stadiums, cars, trees, pillars, walls, and maps (terrain). , An object composed of primitives such as a free-form surface or a subdivision surface) is set in the object space. For example, the position and rotation angle (synonymous with the direction and direction of the object in the world coordinate system, for example, rotation when rotating clockwise when viewed from the positive direction of each axis of the X, Y, and Z axes in the world coordinate system. The angle is determined, and the object is arranged at the position (X, Y, Z) at the rotation angle (rotation angle about the X, Y, Z axis).

  The movement / motion processing unit 112 performs movement / motion calculation (movement / motion simulation) of an object (a character, a moving body, etc.). In other words, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), a physical law, or the like, the object is moved in the object space or the object is moved ( (Motion, animation). Specifically, object movement information (position, rotation angle, speed, or acceleration) and motion information (position or rotation angle of each part that constitutes the object) are sequentially transmitted every frame (1/60 seconds). Perform the required simulation process. A frame is a unit of time for performing object movement / motion processing (simulation processing) and image generation processing.

  The virtual camera control unit 114 performs a virtual camera (viewpoint) control process for generating an image viewed from a given (arbitrary) viewpoint in the object space. Specifically, the position (X, Y, Z) or rotation angle of the virtual camera in the world coordinate system (for example, the rotation angle when rotating in the clockwise direction when viewed from the positive direction of each axis of the X, Y, and Z axes). Process to control. In short, processing for controlling the viewpoint position, the line-of-sight direction, and the angle of view is performed. For example, the virtual camera control unit 114 may control the virtual camera to follow the movement of the moving object. That is, when an object (for example, a character or a moving object) is photographed from behind using a virtual camera, the position or rotation angle of the virtual camera (the direction of the virtual camera) is set so that the virtual camera follows changes in the position or rotation of the object. ) To control. In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112. Alternatively, the virtual camera may be controlled to rotate at a predetermined rotation angle or to move along a predetermined movement path. In this case, the virtual camera is controlled based on the virtual camera data for specifying the position (movement path) or rotation angle of the virtual camera. When there are a plurality of virtual cameras (viewpoints), the above control process is performed for each virtual camera.

  The drawing unit 120 performs drawing processing based on the results of various processing (game processing) performed by the processing unit 100, thereby generating an image and outputting the image to the display unit 190. When generating a so-called three-dimensional game image, first, object data (model data) including vertex data (vertex position coordinates, texture coordinates, color data, normal vector, α value, etc.) of each vertex of the object (model) ) Is input, and vertex processing (shading by a vertex shader) is performed based on the vertex data included in the input object data. When performing the vertex processing, vertex generation processing (tessellation, curved surface division, polygon division) for re-dividing the polygon may be performed as necessary.

  In the vertex processing, in accordance with the vertex processing program (vertex shader program, first shader program), vertex movement processing, coordinate transformation, for example, world coordinate transformation, visual field transformation (camera coordinate transformation), clipping processing, projective transformation (viewpoint conversion) Geometry processing such as perspective conversion, projection conversion), viewport conversion (screen coordinate conversion), and light source calculation is performed, and based on the processing results, the vertex data given to the vertex group that composes the object is changed. (Update, adjust). Object data after the geometry processing (position coordinates of object vertices, texture coordinates, color data (luminance data), normal vector, α value, etc.) is stored in the object data storage unit 176.

  Then, rasterization (scan conversion) is performed based on the vertex data after the vertex processing, and the surface of the primitive (polygon) is associated with the pixel. Subsequent to rasterization, pixel processing (shading or fragment processing by a pixel shader) for drawing pixels (fragments forming a display screen) constituting an image is performed. In pixel processing, according to a pixel processing program (pixel shader program, second shader program), various processes such as texture reading (texture mapping), color data setting / change, translucent composition, anti-aliasing, etc. are performed, and an image is processed. Determining the final drawing color of the constituent pixels and drawing the drawing color of the perspective-transformed object into a drawing buffer 174 (buffer that can store image information in units of pixels such as a frame buffer and an intermediate buffer (work buffer). VRAM, rendering Output (draw) to the target. That is, in pixel processing, per-pixel processing for setting or changing image information (color, normal, luminance, α value, etc.) in units of pixels is performed. Thereby, an image that can be seen from the virtual camera (given viewpoint) in the object space is generated. Note that when there are a plurality of virtual cameras (viewpoints), an image can be generated so that an image seen from each virtual camera can be displayed as a divided image on one screen.

  Note that the vertex processing and pixel processing are realized by hardware that enables the rendering processing of primitives (polygons) to be programmed by a shader program written in a shading language, so-called programmable shaders (vertex shaders and pixel shaders). Programmable shaders can be programmed with vertex-level processing and pixel-level processing, so that the degree of freedom of drawing processing is high, and expressive power is greatly improved compared to conventional hardware-based fixed drawing processing. Can do.

  The drawing unit 120 performs texture mapping, hidden surface removal processing, α blending, and the like when drawing the object.

  Texture mapping is a process for mapping a texture (texel value) stored in the texture storage unit 178 of the storage unit 170 to an object. Specifically, the texture (surface properties such as color (RGB) and α value) is read from the texture storage unit 178 of the storage unit 170 using the texture coordinates set (given) at the vertex of the object. Then, a texture that is a two-dimensional image is mapped to an object. In this case, processing for associating pixels with texels, bilinear interpolation or the like is performed as texel interpolation.

  As the hidden surface removal processing, hidden surface removal processing by a Z buffer method (depth comparison method, Z test) using a Z buffer 179 (depth buffer) in which a Z value (depth information) of a drawing pixel is stored may be performed. it can. That is, when drawing pixels corresponding to the primitive of the object are drawn, the Z value stored in the Z buffer 179 is referred to. Then, the Z value of the referenced Z buffer 179 is compared with the Z value at the drawing pixel of the primitive, and the Z value at the drawing pixel is the front side when viewed from the virtual camera (for example, a small Z value). If it is, the drawing process of the drawing pixel is performed and the Z value of the Z buffer 179 is updated to a new Z value.

  α blending (α synthesis) is a translucent synthesis process (usually α blending, addition α blending, subtraction α blending, or the like) based on an α value (A value).

  The α value is information that can be stored in association with each pixel (texel, dot), for example, plus alpha information other than color information. The α value can be used as mask information, translucency (equivalent to transparency and opacity), bump information, and the like.

  In particular, in the present embodiment, the drawing unit 120 includes a particle generation unit 122, a distance information calculation unit 124, a blur amount calculation unit 126, a particle size change unit 128, and a blur image generation unit 129.

  The particle generator 122 generates a given particle at a given position in the object space.

  The distance information calculation unit 124 calculates distance information of the virtual camera and particles in the line-of-sight direction of the virtual camera.

  The blur amount calculation unit 126 calculates the blur amount according to the position of the particle. For example, the blur amount calculation unit 126 may calculate the blur amount according to the distance between the virtual camera and the particles in the line-of-sight direction of the virtual camera as the blur amount according to the position of the particle. Further, for example, the blur amount calculation unit 126 may calculate the blur amount according to the linear distance between the virtual camera and the particle as the blur amount according to the position of the particle.

  The particle size changing unit 128 enlarges or reduces the particles according to the blur amount calculated by the blur amount calculating unit 126.

  The blurred image generation unit 129 determines whether or not the position of the particle is within a given blurring target range based on the distance information calculated by the distance information calculation unit 124. A blur image of particles corresponding to the blur amount calculated by the amount calculator 126 is generated. For example, the blurred image generation unit 129 may generate a blurred image corresponding to the blur amount calculated by the blur amount calculation unit 126 for the particles after the particle size changing unit 128 has enlarged or reduced.

  The sound generation unit 130 performs sound processing based on the results of various processes performed by the processing unit 100, generates game sounds such as BGM, sound effects, or sounds, and outputs the game sounds to the sound output unit 192.

  Note that the image generation system of the present embodiment may be a system dedicated to the single player mode in which only one player can play, or may be a system having a multiplayer mode in which a plurality of players can play. Further, when a plurality of players play, game images and game sounds to be provided to the plurality of players may be generated using one terminal, or connected via a network (transmission line, communication line) or the like. Alternatively, it may be generated by distributed processing using a plurality of terminals (game machine, mobile phone).

2. Techniques of this embodiment (1) Outline In this embodiment, processing is performed in real time to generate an image in which petals, snow, rain, smoke, flames, and other particles are blurred according to a pseudo depth of field. Is. For example, as shown in FIG. 2, one petal is realized with one particle, and a simulation process is performed in which the origin of each particle is moved based on a physical law of motion such as gravity or wind force. An image is generated by mapping (petal pattern texture). At that time, a focused petal image is generated for particles (eg, Pd, Pe) that are not in the blurring target range according to the depth of field. On the other hand, a blurred image of petals is generated for particles (for example, Pa, Pb, Pc, Pf) in the blurring target range. In particular, a blurred petal image is also generated for the particle Pc that is in front of the character C that is partially in focus. Hereinafter, the method of this embodiment will be described.

(2) Particle Blur Processing In the present embodiment, as shown in FIG. 3, in the world coordinate system, each particle P0, P1, P2, P3 facing the line of sight of the virtual camera CM at a position based on simulation processing. P4, P5,... Are generated. Coordinate conversion processing from the world coordinate system to the camera coordinate system (coordinate system in which the viewpoint is the origin and the direction of the line of sight is the negative direction of the z axis) for each of the four vertices of this particle That is, when the visual field conversion process is performed, the z coordinates in the camera coordinate system of the four vertices of each particle all have the same value. Then, for each particle, the absolute value of the z coordinate values of the four vertices is used as relative distance information with respect to the virtual camera CM to determine whether or not the position of each particle is within the blurring target range.

  FIG. 4 shows an example of the blur target range according to the depth of field. FIG. 4 is a diagram viewed from the positive direction of the y-axis of the camera coordinate system. A range (space) in which the distance in the negative direction of the z-axis with respect to the xy plane of the camera coordinates is dmin to dmax is the depth of field 200. Further, a range (space) where the distance in the negative direction of the z-axis with respect to the xy plane of the camera coordinates is smaller than dmin (space) and a range (space) larger than dmax become the front blur range 210 and the back blur range 220, respectively. When the particle Pn is in the coordinates (xn, yn, zn) of the camera coordinate system, the length dn (equal to the absolute value of zn) of the perpendicular line drawn from the center of the particle Pn to the xy plane is virtual with the particle Pn. This is the distance in the z direction of the camera CM. That is, a particle Pn having a distance dn of dmin or more and dmax or less exists in the depth of field 200, a particle Pn having a distance dn smaller than dmin exists in the near blur range 210, and a particle Pn having a distance dn larger than dmin. Exists in the back blur range 220. In the example of FIG. 4, the particles P <b> 2 and P <b> 3 exist in the depth of field 200, the particles P <b> 0 and P <b> 1 exist in the near blur area 210, and the particles P <b> 2 and P <b> 3 exist in the back blur area 220.

  In the present embodiment, the front blur range 210 and the back blur range 220 are blur target ranges. When the particle Pn is present in the front blur range 210 or the back blur range 220, a blurred image of the particle is generated, and when the particle Pn is not present in the front blur range 210 or the back blur range 220 (in other words, the depth of field). In the case of 200, a normal image (unblurred image) of particles is generated.

  In the present embodiment, when generating a blurred image, the blur amount is changed according to the distance dn of the particles Pn. Specifically, the blurring amount is increased as the particle Pn moves away from the depth of field 200. That is, when the particle Pn exists in the near blurring range 210, the blurring amount increases as the distance dn decreases, and when the particle Pn exists in the back blurring range 220, the blurring amount increases as the distance dn increases. In the example of FIG. 4, the particles P0 and P1 exist in the near blurring range 210 and d0 <d1, so the blurring amount for the particle P0 is set larger than the blurring amount for the particle P1. Further, since particles P4 and P5 exist in the back blur range 220 and d4 = d5, the blur amount for the particle P4 and the blur amount for the particle P5 are the same.

  Alternatively, as shown in FIG. 5, when the particle Pn exists in the blurring target range, the linear distance rn between the particle Pn and the origin of the camera coordinate system (rn is the radius of the spherical surface including the particle Pn centered on the origin. The blurring amount may be changed according to (equal). Specifically, when the particle Pn exists in the near blurring range 210, the blurring amount increases as the linear distance rn decreases, and when the particle Pn exists in the back blurring range 220, the blurring amount increases as the linear distance rn increases. Enlarge. In the example of FIG. 4, the particles P0 and P1 exist in the front blurring range 210, and r1> r0, so the blurring amount for the particle P1 is set larger than the blurring amount for the particle P0. Further, since particles P4 and P5 exist in the back blurring range 220 and r4> r5, the blurring amount for the particle P4 is set larger than the blurring amount for the particle P5.

  Next, particle image generation according to the present embodiment will be described with reference to FIGS. 6 (A) and 6 (B).

  When the particle Pn does not exist in the blurring target range (front blurring range 210 and back blurring range 220) (in other words, in the depth of field 200), first, as shown in FIG. A particle 300 is generated by converting the vertices to the screen coordinate system. Then, the texture 400 is mapped onto the particle 300 and drawn without blurring, and a normal image 500 of the particle is generated.

  On the other hand, when the particle Pn exists in the blurring target range (front blurring range 210 or back blurring range 220), as shown in FIG. 6B, first, the particle Pn is set according to the blurring amount calculated from the distance information. A particle 310 is generated by enlarging or reducing. For example, the particle 310 is enlarged or reduced by changing the position of each vertex while keeping the center (centroid) of the particle 310 coincident with the center (centroid) of the particle Pn. Then, a particle 320 is generated by converting each vertex of the particle 310 into the screen coordinate system. The particle 400 is rendered with the texture 400 blurred according to the blur amount, and a particle blur image 510 is generated. For example, the blurred image 510 can be generated by mapping the particle 320 with the number of times and the color (thinness) according to the blur amount while shifting the texture 400.

  When the size of the particle Pn is small, if the texture 400 is drawn as it is converted into the screen coordinate system as it is, there is a possibility that a blurred image in which a part of the particle is not drawn without being drawn inside depending on the amount of blur is generated. is there. Therefore, in the present embodiment, the particle Pn is enlarged in advance according to the blur amount and then converted to the particle 320 in the screen coordinate system, so that the blur image is surely drawn inside the particle 320.

  Conversely, when the size of the particle Pn is large, the texture 400 may be drawn by converting it directly into a particle in the screen coordinate system, but the drawing load can be further reduced as the particle is smaller. Therefore, in the present embodiment, the drawing load of the blurred image is reduced by reducing the particles in advance according to the blur amount and then converting the particles into the particles 320 of the screen coordinate system.

  Since the drawing load can be reduced as the particle 320 becomes smaller, it is desirable to enlarge or reduce the particle Pn so that the particle 320 is slightly larger than the drawing area of the blurred image.

3. Process of this embodiment (1) Blur process Next, the blur process of this embodiment will be described with reference to the flowchart of FIG.

  First, in the world coordinate system, a particle Pn is generated at a given position and is placed facing the virtual camera CM (step S10).

  Next, the coordinates of the particles Pn arranged in the world coordinate system in step S10 are converted into the camera coordinate system (step S20).

  Next, in the camera coordinate system, distance information in the line-of-sight direction (the negative direction of the z-axis) between the particle Pn and the origin (virtual camera position) is calculated (step S30).

  Next, it is determined from the distance information calculated in step S30 whether the particle Pn is in the blurring target range (step S40).

  When the particle Pn is in the blurring target range (in the case of Y in step S50), the blur amount is calculated according to the distance information calculated in step S30, and the particle Pn is enlarged or reduced according to the blur amount. Is generated (step S60).

  Next, the particles 310 generated in step S60 are converted into particles 320 in the screen coordinate system (step S70).

  Next, rasterization is performed on the particles 320 generated in step S70 to generate pixel data (step S80).

  Next, with respect to the pixel data generated in step S80, the texture 400 is mapped a plurality of times with the number of times and the color corresponding to the amount of blur while shifting the drawing position, thereby generating a particle blur image 510 (step S90).

  On the other hand, if the particle Pn is not in the blurring target range (N in step S50), the particle Pn is converted to a particle 300 in the screen coordinate system (step S72).

  Next, rasterization is performed on the particle 300 generated in step S72 to generate pixel data (step S82).

  Next, the texture 400 is mapped to the pixel data generated in step S82, and a normal particle image 500 is generated (step S92).

  Then, after the processing of step S90 or S92 is completed, if there are other particles Pn to be drawn (in the case of Y in step S100), the processing after step S20 is similarly performed, and if there are no other particles Pn to be drawn. (In the case of N in step S100) The blurring process is terminated.

  As described above, in the present embodiment, distance information in the visual line direction (the negative direction of the z axis) of the virtual camera CM between the virtual camera CM and the particle Pn is calculated, and a blurred image of the particle is generated based on the distance information. Therefore, it is not necessary to write depth information to the Z buffer 179 for the particles. Therefore, according to the present embodiment, it is possible to reproduce the blur due to the depth of field with a relatively light drawing load with respect to the particles.

  In addition, according to the present embodiment, by appropriately adjusting the size of the particle Pn according to the amount of blurring, the rendering process is performed on particles as small as possible including the rendering area of the blurred image. Is possible. Thereby, the drawing load of the blurred image can be reduced.

(2) Blur Processing Allocation Control In this embodiment, distance information calculation (distance information calculation processing) in step S30 in FIG. 7, particle enlargement or reduction (particle size change processing) in step S60, and blurred image in step S90 Control (blurred image generation processing) is assigned to one of the main processor (CPU), the vertex shader of the drawing processor (GPU), and the pixel shader of the drawing processor (GPU). In this embodiment, one of the three allocation patterns shown in FIG. 8 is selected.

  In pattern 1, distance information calculation processing and particle size change processing are assigned to the main processor (CPU), and a blurred image generation processing is assigned to the pixel shader of the drawing processor (GPU). If this pattern 1 is selected, the burden on the main processor (CPU) increases and the burden on the drawing processor (GPU) decreases. Therefore, for example, if the processing load of the drawing processor (GPU) is relatively heavy, the pattern 1 may be selected.

  Pattern 2 assigns distance information calculation processing, particle size change processing, and blurred image generation processing to the main processor (CPU), the vertex shader of the drawing processor (GPU), and the pixel shader of the drawing processor (GPU), respectively. If this pattern 2 is selected, the balance between the load on the main processor (CPU) and the load on the drawing processor (GPU) is good. Therefore, for example, if the processing load of the main processor (CPU) and the processing load of the drawing processor (GPU) are not so heavy, the pattern 2 may be selected.

  In pattern 3, the distance information calculation process and the particle size change process are assigned to the vertex shader of the drawing processor (GPU), and the blurred image generation process is assigned to the pixel shader of the drawing processor (GPU). If this pattern 3 is selected, the burden on the main processor (CPU) is reduced, and the burden on the drawing processor (GPU) is increased. Therefore, for example, if the processing load of the main processor (CPU) is relatively heavy, the pattern 3 may be selected.

  The selection of the allocation pattern may be controlled so as to be dynamically changed immediately before the blurring process or in the middle of the blurring process.

  As an example, FIG. 9 shows patterns 1, 2, and 3 based on the currently selected allocation pattern and the current processing load of each of the main processor (CPU) and the drawing processor (GPU). The flowchart of the control to change automatically is shown.

  First, for example, pattern 2 is selected, and distance information calculation processing, particle size change processing, and blurred image generation processing are performed respectively for a main processor (CPU), a drawing processor (GPU) vertex shader, and a drawing processor (GPU) pixel shader. (Step S200).

  If the drawing process is not completed (N in step S210), the processing load on the main processor (CPU) and the processing load on the drawing processor (GPU) are determined at a given timing. When the processing load of the main processor (CPU) is equal to or less than the threshold and the processing load of the drawing processor (GPU) is larger than the threshold (Y in step S220 and N in step S230), the particle size The allocation of the change process is changed to the main processor (CPU) (step S240). That is, the pattern 2 is changed to the pattern 1. Thereby, the processing load of the drawing processor (GPU) can be reduced.

  Further, when the processing load on the main processor (CPU) is larger than the threshold and the processing load on the drawing processor (GPU) is equal to or less than the threshold (N in step S220 and Y in step S232), distance information calculation is performed. The processing assignment is changed to the vertex shader of the drawing processor (GPU) (step S242). That is, the pattern 2 is changed to the pattern 3. Thereby, the processing load of the main processor (CPU) can be reduced.

  Further, when the processing load of the main processor (CPU) and the processing load of the drawing processor (GPU) are both equal to or less than the threshold value (Y in step S220 and Y in step S230), or the processing load of the main processor (CPU) When the processing load on the drawing processor (GPU) is larger than the threshold value (N in step S220 and N in step S232), the pattern 2 remains unchanged. In the former case, since pattern 2 is considered to be an efficient allocation, it is not changed to pattern 1 or pattern 3, and in the latter case, the processing load of either the main processor (CPU) or the drawing processor (GPU) is a threshold value. Waiting for the following to change to pattern 1 or pattern 3.

  If the drawing process is not completed after changing from pattern 2 to pattern 1 in step S240 (N in step S250), the processing load of the main processor (CPU) and the processing of the drawing processor (GPU) at a given timing Determine the load. When the processing load on the main processor (CPU) is larger than the threshold and the processing load on the drawing processor (GPU) is equal to or less than the threshold (N in step S260 and Y in step S270), the particle size is changed. The processing assignment is changed to the vertex shader of the drawing processor (GPU) (step S280). That is, the pattern 1 is changed to the pattern 2. Thereby, the processing load of the main processor (CPU) can be reduced.

  Also, when the processing load of the main processor (CPU) is equal to or less than the threshold value (in the case of Y in step S260), or when both the processing load of the main processor (CPU) and the processing load of the drawing processor (GPU) are larger than the threshold value (N in step S260 and N in step S270), pattern 1 remains unchanged. In the former case, pattern 1 is considered to be an efficient allocation, so it is not changed to pattern 2. In the latter case, the pattern processor is changed to pattern 2 after the processing load of the drawing processor (GPU) falls below the threshold. .

  On the other hand, if the drawing process is not completed after changing from pattern 2 to pattern 3 in step S242 (N in step S252), the processing load of the main processor (CPU) and the drawing processor (GPU) at a given timing. The processing load is determined. When the processing load of the drawing processor (GPU) is larger than the threshold and the processing load of the main processor (CPU) is equal to or less than the threshold (N in step S262 and Y in step S272), distance information calculation is performed. The process assignment is changed to the main processor (CPU) (step S282). That is, the pattern 3 is changed to the pattern 2. Thereby, the processing load of the drawing processor (GPU) can be reduced.

  Further, when the processing load of the drawing processor (GPU) is equal to or less than the threshold (in the case of Y in step S262), or when the processing loads of the processing load of the drawing processor (GPU) and the main processor (CPU) are both greater than the threshold (N in step S262 and N in step S272), pattern 3 remains unchanged. In the former case, since pattern 3 is considered to be an efficient allocation, it is not changed to pattern 2, and in the latter case, the pattern is changed to pattern 2 after the processing load of the main processor (CPU) falls below the threshold value. .

  After changing from pattern 1 to pattern 2 in step S280, or after changing from pattern 3 to pattern 2 in step S282, if the drawing process is not completed (N in step S210), the same process as described above A change process from pattern 2 to pattern 1 or pattern 3 is performed according to the processing load of the main processor (CPU) and the processing load of the drawing processor (GPU).

  By repeating the above-described processing until the drawing processing is completed, distance information calculation processing, particle size change processing, and blurred image generation are performed according to the processing load of the main processor (CPU) and the processing load of the drawing processor (GPU). Processing assignment can be changed dynamically.

  As another example, FIG. 10 shows a flowchart of control for dynamically changing the patterns 1, 2, and 3 according to the number of particles to be drawn (or the total area of the particles).

  First, the number of particles to be drawn (or the total area of particles) is determined at a given timing (step S300).

  If the number of particles is less than N1 (or the total area of particles is less than S1) (Y in step S310), pattern 1 is selected, and distance information calculation processing and particle size change processing are performed on the main processor (CPU). The blurred image generation process is assigned to each pixel shader of the drawing processor (GPU) (step S320).

  If the number of particles is greater than or equal to N1 and less than N2 (or the total area of particles is greater than or equal to S1 and less than S2) (N in step S310 and Y in step S330), pattern 2 is selected and distance information calculation processing is performed. The particle size changing process and the blurred image generating process are assigned to the main processor (CPU), the vertex shader of the drawing processor (GPU), and the pixel shader of the drawing processor (GPU), respectively (step S340).

  If the number of particles is greater than or equal to N2 (or the total area of the particles is greater than or equal to S2) (N in step S330), the pattern 3 is selected, and the distance information calculation process and the particle size change process are performed as a drawing processor (GPU). Is assigned to the pixel shader of the rendering processor (GPU) (step S350).

  In this way, even if the number of particles increases (or even if the total area of the particles becomes large), the main processor (CPU) is not subjected to an excessive processing load, and the blurring process is prevented from slowing down. it can. As described above, the blurring process can be efficiently performed by changing the processing load of the main processor (CPU) and the drawing processor (GPU) according to the number of particles and the total area.

4). Hardware Configuration Next, a hardware configuration capable of realizing the present embodiment will be described with reference to FIG. FIG. 11 is an example of a hardware configuration that can realize this embodiment.

  The main processor 900 operates based on a program stored in a DVD 982 (information storage medium, which may be a CD), a program downloaded via the communication interface 990, a program stored in the ROM 950, or the like. Perform processing, sound processing, etc.

  The coprocessor 902 assists the processing of the main processor 900, and executes matrix operation (vector operation) at high speed. For example, when a matrix calculation process is necessary for a physical simulation for moving or moving an object, a program operating on the main processor 900 instructs (requests) the process to the coprocessor 902.

  The geometry processor 904 performs geometry processing such as coordinate conversion, perspective conversion, light source calculation, and curved surface generation based on an instruction from a program operating on the main processor 900, and executes matrix calculation at high speed. The data decompression processor 906 performs decoding processing of compressed image data and sound data, and accelerates the decoding processing of the main processor 900. Thereby, a moving image compressed by the MPEG method or the like can be displayed on the opening screen or the game screen.

  The drawing processor 910 executes drawing (rendering) processing of an object composed of primitive surfaces such as polygons and curved surfaces. When drawing an object, the main processor 900 uses the DMA controller 970 to pass the drawing data to the drawing processor 910 and, if necessary, transfers the texture to the texture storage unit 924. Then, the drawing processor 910 draws the object in the frame buffer 922 while performing hidden surface removal using a Z buffer or the like based on the drawing data and texture.

  The drawing processor 910 also performs α blending (translucent processing), depth queuing, mip mapping, fog processing, bilinear filtering, trilinear filtering, anti-aliasing, shading processing, and the like. When an image for one frame is written in the frame buffer 922, the image is displayed on the display 912.

  Each function of each of the processors may be realized by a separate processor as hardware, or may be realized by one processor. In addition, even when a CPU and a GPU are provided as processors, it is possible to arbitrarily set which function is realized by which processor.

  The sound processor 930 includes a multi-channel ADPCM sound source and the like, generates game sounds such as BGM, sound effects, and sounds, and outputs them through the speaker 932. Data from the game controller 942 and the memory card 944 is input via the serial interface 940.

  The ROM 950 stores system programs and the like. In the case of an arcade game system, the ROM 950 functions as an information storage medium, and various programs are stored in the ROM 950. A hard disk may be used instead of the ROM 950.

  The RAM 960 serves as a work area for various processors. The DMA controller 970 controls DMA transfer between the processor and the memory. The DVD drive 980 accesses a DVD 982 in which programs, image data, sound data, and the like are stored. The communication interface 990 performs data transfer with the outside via a network (communication line, high-speed serial bus).

  The processing of each unit (each unit) in this embodiment may be realized entirely by hardware, or may be realized by a program stored in an information storage medium or a program distributed via a communication interface. May be. Alternatively, it may be realized by both hardware and a program.

  When the processing of each unit of this embodiment is realized by both hardware and a program, a program for causing the hardware (computer) to function as each unit of this embodiment is stored in the information storage medium. . More specifically, the program instructs the processors 902, 904, 906, 910, and 930, which are hardware, and passes data if necessary. Each processor 902, 904, 906, 910, 930 realizes the processing of each unit of the present invention based on the instruction and the passed data.

  The present invention is not limited to that described in the above embodiment, and various modifications can be made. For example, terms cited as broad or synonymous terms in the description in the specification or drawings can be replaced with broad or synonymous terms in other descriptions in the specification or drawings.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

P, Pa, Pb, Pc, Pd, Pe, Pf particles, C character, P0 to P5, Pn particles, CM virtual camera, 100 processing unit, 110 object space setting unit, 112 movement / motion processing unit, 114 virtual camera control 116, blur processing allocation control unit, 120 drawing unit, 122 particle generation unit, 124 distance information calculation unit, 126 blur amount calculation unit, 128 particle size change unit, 129 blurred image generation unit, 130 sound generation unit, 160 operation unit , 170 storage unit, 172 main storage unit, 174 drawing buffer, 176 object data storage unit, 178 texture storage unit, 179 Z buffer, 180 information storage medium, 190 display unit, 192 sound output unit, 196 communication unit, 200 subject Depth of field, 210 front blur Range, 220 Back Blur Range, 300, 310 Particles, 400 Texture, 500 Normal Image, 510 Blur Image

Claims (9)

A program for generating an image visible from a virtual camera in an object space,
A particle generator for generating a given particle at a given position in the object space;
A distance information calculation unit that calculates distance information of the virtual camera and the particles in the viewing direction of the virtual camera;
A blur amount calculation unit for calculating a blur amount according to the position of the particle;
Based on the distance information, it is determined whether or not the position of the particle is within a given blurring target range, and if it is within the blurring target range, a blur image of the particle corresponding to the blur amount is generated. A program that causes a computer to function as a blurred image generation unit. In claim 1,
Further causing the computer to function as a particle size changing unit that enlarges or reduces the particles according to the blur amount,
The blurred image generation unit
A program for generating the blurred image corresponding to the blur amount for the particles after being enlarged or reduced. In claim 1 or 2,
The blur amount calculation unit
A program for calculating a blur amount corresponding to a distance between the virtual camera and the particles in a visual line direction of the virtual camera as the blur amount. In claim 1 or 2,
The blur amount calculation unit
A program for calculating a blur amount corresponding to a linear distance between the virtual camera and the particles as the blur amount. In any of claims 2 to 4,
The computer includes a main processor and a drawing processor;
The computer is further caused to function as a blurring process assignment control unit that controls which of the processing of the distance information calculation unit, the blurred image generation unit, and the particle size changing unit is assigned to the main processor or the drawing processor. Program. In claim 5,
The blur processing assignment control unit
Controlling whether to assign each process to the main processor or the drawing processor based on the current allocation status of each process and the current processing load of each of the main processor and the drawing processor A program characterized by In claim 5,
The blur processing assignment control unit
A program that controls whether to assign each of the processes to the main processor or the drawing processor according to the number or total area of the particles to be drawn.   An information storage medium readable by a computer, wherein the program according to any one of claims 1 to 7 is stored. An image generation system for generating an image visible from a virtual camera in an object space,
A particle generator for generating a given particle at a given position in the object space;
A distance information calculation unit that calculates distance information of the virtual camera and the particles in the viewing direction of the virtual camera;
A blur amount calculation unit for calculating a blur amount according to the position of the particle;
Based on the distance information, it is determined whether or not the position of the particle is within a given blurring target range, and if it is within the blurring target range, a blur image of the particle corresponding to the blur amount is generated. An image generation system comprising: a blurred image generation unit.