JP2007272355A - Program, information storage medium and image generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a program for achieving real wrinkle expressions by simple processing. <P>SOLUTION: This image generation system is provided with a motion processing part for performing the motion processing of a model object where at least one control part for wrinkle expressions is set; a control point operation part for searching the position of a control point whose position changes due to motion change; a texture storage part for storing a plurality of wrinkle expression textures for expressing the wrinkles of the surface of the model object; a parameter operation part for searching the composite parameter of the plurality of wrinkle expression textures based on the control point; and an image generation part for generating a wrinkle image by compounding the plurality of wrinkles expression textures based on the composite parameter, and mapping the composite texture on the model object. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 objects such as characters and cars are arranged and set is known. It is very popular for experiencing so-called virtual reality. Taking an image generation system for enjoying a soccer game as an example, the player enjoys the game by manipulating the characters displayed on the screen and dribbling or shooting.

In such an image generation system, the demand for realism of the generated image is increasing year by year. Therefore, it is desirable that the character's clothes and skin wrinkles can be expressed realistically.
JP-A-11-144084

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a program, an information storage medium, and an image generation system that can realize real wrinkle expression with simple processing. is there.

  The present invention is an image generation system for generating an image, and includes a motion processing unit that performs motion processing of a model object in which at least one control point for wrinkle expression is set, and a position of the motion object according to a change in motion of the model object. A control point calculation unit for obtaining the position of the control point at which changes, a texture for expressing wrinkles on the surface of the model object, and a texture storage unit for storing a plurality of wrinkle expressing textures having different texture patterns; Based on the control points, a parameter calculation unit that obtains a composite parameter of a plurality of wrinkle expression textures, a plurality of wrinkle expression textures are synthesized by the obtained synthesis parameters, and the obtained composite texture is mapped to a model object To create a wrinkled image of the model object. Relating to an image generation system comprising an image generator for. The present invention also relates to a program that causes a computer to function as each of the above-described units, or a computer-readable information storage medium that stores the program.

  According to the present invention, the position of the control point set in the model object changes due to the change in the motion of the model object. Then, a synthesis parameter is obtained based on such control points, a plurality of wrinkle expression textures are synthesized based on the synthesis parameter, and the obtained synthesized texture is mapped to the model object. Therefore, according to the present invention, the synthesis parameter changes in conjunction with the motion change of the model object, and the synthesis texture also changes. Accordingly, the wrinkle image also changes in conjunction with the change in the motion of the model object, and real wrinkle expression can be realized with a simple process.

  In the image generation system, the program, and the information storage medium according to the present invention, the control point calculation unit obtains the position of the control point by coordinate transformation using a coordinate transformation matrix used for the motion processing, and the parameter The calculation unit may obtain the synthesis parameter based on the position of the control point obtained by coordinate conversion.

  If the coordinate conversion matrix for motion processing is effectively used in this way, the position of the control point that changes due to a change in motion can be obtained by simple processing.

  In the image generation system, the program, and the information storage medium according to the present invention, the control point calculation unit obtains the position of the control point in the world coordinate system by coordinate conversion using a coordinate conversion matrix, and the parameter calculation unit. May determine the composite parameter based on the position of the control point in the world coordinate system.

  In this way, it is possible to obtain the synthesis parameter based on the positional relationship and the directional relationship with respect to the control points in the world coordinate system.

  In the image generation system, the program, and the information storage medium according to the present invention, the control point calculation unit may perform coordinate transformation using a coordinate transformation matrix when the skeleton of the model object is composed of a plurality of bones and a plurality of joints. To determine a relative position of the control point with respect to a given joint among the plurality of joints, and the parameter calculator is configured to determine the relative position of the control point with respect to the given joint based on the relative position of the control point. A synthesis parameter may be obtained.

  In this way, the wrinkle image can be changed by changing the synthesis parameter in conjunction with the change in the relative position of the control points, and a more real wrinkle image can be generated.

  In the image generation system, the program, and the information storage medium according to the present invention, first and second control points for wrinkle expression are set for the model object, and the parameter calculation unit includes the first and second control points. The synthesis parameter may be obtained based on the positions of the control points.

  In this way, the composite parameter changes and the generated wrinkle image also changes according to the difference in the way of changing the position of the first control point and the way of changing the position of the second control point. Thus, it becomes possible to generate various wrinkle images.

  In the image generation system, the program, and the information storage medium according to the present invention, the parameter calculation unit includes a first distance between the first control point and another control point or a reference point, and the second control point. A second distance between the control point and another control point or a reference point may be obtained, and the composite parameter may be obtained based on the obtained first and second distances.

  In this way, it is possible to generate a wrinkle image by obtaining the synthesis parameter by a simple process of obtaining the first and second distances between the first and second control points and other control points or reference points. It becomes like this.

  In the image generation system, the program, and the information storage medium according to the present invention, the parameter calculation unit may obtain the composite parameter that changes according to a ratio of the first and second distances.

  In this way, a wrinkle image can be generated by changing the synthesis parameter by changing the ratio of the first and second distances.

  In the image generation system, the program, and the information storage medium according to the present invention, when the skeleton of the model object includes a plurality of bones and a plurality of joints, the front side of the given joint among the plurality of joints A control point is set, a rear control point is set behind the given joint, and the control point calculation unit is configured to change the position of the front control point whose position changes due to a change in motion of the model object, and The position of the rear control point is obtained, the parameter calculation unit obtains a first synthesis parameter based on the front control point, obtains a second synthesis parameter based on the rear control point, and the image generation unit Synthesizes a plurality of wrinkle expressing textures according to the obtained first synthesis parameter, and maps the obtained synthesized texture to the front side of the model object. To generate a wrinkle image on the front side of the model object, synthesize a plurality of wrinkle expressing textures with the obtained second synthesis parameter, and map the obtained synthesized texture to the back side of the model object Thus, a wrinkle image on the back side surface of the model object may be generated.

  In this way, it is possible to change the way the wrinkles change on the front side of the model object and the way the wrinkles change on the back side of the model object, and it is possible to generate more diverse and real wrinkle images become.

  The image generation system, the program, and the information storage medium according to the present invention include a texture coordinate setting unit that sets a texture coordinate for fetching a texel value of the wrinkle expression texture (the computer functions as the texture coordinate setting unit). The texture storage unit stores the wrinkle expression texture as a volume texture from which texel values are fetched at the first, second, and third texture coordinates, and the texture coordinate setting unit is based on the synthesis parameter. The third texture coordinates of the volume texture are set, and the image generation unit performs a process of mapping the wrinkle expression texture as a volume texture to the model object based on the first, second, and third texture coordinates. You may make it perform.

  In this way, the composite texture mapping process is performed by effectively utilizing the volume texture function, so that the processing load can be reduced and the processing speed can be increased.

  The present invention is also an image generation system for generating an image, which is a texture for expressing wrinkles on the surface of a model object, and stores a plurality of wrinkle expression textures having different texture patterns; A texture coordinate setting unit for setting a texture coordinate for fetching the texel value of the wrinkle expression texture, a parameter calculation unit for obtaining a composite parameter of a plurality of wrinkle expression textures, and an image generation unit for generating a wrinkle image of the model object The texture storage unit stores the wrinkle expression texture as a volume texture from which texel values are fetched at the first, second, and third texture coordinates, and the texture coordinate setting unit stores the texture parameter as the synthesis parameter. Based on the third of the volume texture Set Kusucha coordinates, the image generation unit, the first, second, on the basis of the third texture coordinate is related to the image generation system performs the process of mapping the model object wrinkles representation texture as a volume texture. The present invention also relates to a program that causes a computer to function as each of the above-described units, or a computer-readable information storage medium that stores the program.

  According to the present invention, a plurality of wrinkle expression textures are synthesized based on the synthesis parameter, and the obtained synthesized texture is mapped to the model object. In addition, the composite texture mapping process is performed by effectively utilizing the volume texture function. Accordingly, it is possible to generate a real wrinkle image while reducing the processing load and simplifying the processing.

  Hereinafter, this embodiment will be described. In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration 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, and the function can be realized by a lever, button, steering, accelerator, brake, touch panel display, or the like. 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.

  An information storage medium 180 (a computer-readable medium) stores programs, data, and the like, and its function can be realized by an optical disk (CD, DVD), a hard disk, a memory (ROM, etc.), and the like. The processing unit 100 performs various processes of the present embodiment based on a program (data) stored in the information storage medium 180. That is, in the information storage medium 180, a program for causing a computer (an apparatus including an operation unit, a processing unit, a storage unit, and an output unit) to function as each unit of the present embodiment (a program for causing the computer to execute processing of each unit). Is memorized.

  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 portable information storage device 194 stores player personal data, game save data, and the like. Examples of the portable information storage device 194 include a memory card and a portable game device. The communication unit 196 performs various controls for communicating with the outside (for example, a host device or other image generation system), and functions thereof are hardware such as various processors or communication ASICs, programs, and the like. It can be realized by.

  A program (data) for causing a computer to function as each unit of the present embodiment is distributed from the information storage medium of the host device (server) to the information storage medium 180 (or storage unit 170) via the network and communication unit 196. May be. Use of an information storage medium by such a host device (server) can also be 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. The processing unit 100 performs various processes using the storage unit 170 (main storage unit 172) 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.

  The processing unit 100 includes a game calculation unit 108, an object space setting unit 110, a movement processing unit 112, a motion processing unit 113, a virtual camera control unit 114, a control point calculation unit 116, a parameter calculation unit 118, a texture coordinate setting unit 119, an image. A generation unit 120 and a sound generation unit 130 are included. Note that some of these may be omitted.

  The game calculation unit 108 performs game calculation processing. Here, the game calculation includes 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 moving object or a map, a process for displaying an object, and calculating a game result. Or a process for ending the game when a game end condition is satisfied.

  The object space setting unit 110 includes various objects (polygons, free-form surfaces or subdivision surfaces) representing display objects such as model objects (cars, people, robots, etc.), courses (roads), maps (terrain), buildings, trees, and walls. The object is configured to place and set in the object space. In other words, the position and rotation angle of the object in the world coordinate system (synonymous with direction and direction) are determined, and the rotation angle (rotation angle around the X, Y, and Z axes) is determined at that position (X, Y, Z). Arrange objects. Specifically, model data such as a moving object (character) is stored in the model data storage unit 176 of the storage unit 170. Then, the object space setting unit 110 performs an object setting (arrangement) process in the object space using the model data.

  The movement processing unit 112 performs a calculation for moving a model object (movement of a character, a robot, a car, a tank, or the like). That is, processing for moving the model object in the object space is performed based on operation data, a program (movement algorithm), various data, and the like input by the player through the operation unit 160. Specifically, a simulation process for sequentially obtaining movement information (position, rotation angle, speed, or acceleration) of the model object every frame (1/60 second) is performed. Note that a frame is a unit of time for performing a movement process, a motion process, and an image generation process.

  The motion processing unit 113 performs motion processing (motion reproduction, motion generation) that causes the model object (character) to perform motion (animation). This motion processing can be realized by reproducing the motion of the model object based on the motion data stored in the motion data storage unit 179.

  Specifically, the motion data storage unit 179 stores the position or rotation angle of each bone (part object, joint, and motion bone constituting the model object) constituting the skeleton of the model object (3 of the child bone relative to the parent bone). Motion data including the rotation angle around the axis) is stored. The motion processing unit 113 reads this motion data from the motion data storage unit 179 and moves each bone (part object) constituting the skeleton of the model object based on the read motion data (deforms the skeleton shape). ), Play the motion of the model object.

  The motion data stored in the motion data storage unit 179 can be created by attaching a sensor to a person in the real world and performing motion capture. However, the motion data is generated by physical simulation (simulation using physical calculation. Or may be generated in real time by motion blending. In addition, in order to reproduce a realistic motion with a small amount of motion data, motion reproduction may be performed using inverse kinematics or the like.

  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, processing for controlling the position (X, Y, Z) or rotation angle (rotation angle about the X, Y, Z axis) of the virtual camera (processing for controlling the viewpoint position, the line-of-sight direction or the angle of view) I do.

  For example, when a model object (moving body) such as a car or a character is photographed from behind using a virtual camera, the position or rotation angle (virtual angle of the virtual camera is set so that the virtual camera follows changes in the position or rotation of the model object. Control camera orientation). In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the model object obtained by the movement 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.

  The control point calculation unit 116 performs control point calculation processing for wrinkle expression. That is, in this embodiment, at least one control point is set for the model object. This control point may be the skeleton joint itself of the model object, or may be a point that is set at a given distance from the joint and follows the movement of the joint. In the present embodiment, the motion of the model object changes for each frame by the motion processing of the motion processing unit 113. Then, the control point calculation unit 116 performs a calculation for obtaining the position of the control point whose position changes in conjunction with the change in the motion of the model object.

  For example, the control point calculation unit 116 obtains the position of the control point by coordinate conversion using a coordinate conversion matrix (motion matrix) used for motion processing. For example, the control point is converted from the local coordinate system to the world coordinate system by coordinate conversion using a coordinate conversion matrix, and the position of the control point in the world coordinate system is obtained. Alternatively, when the skeleton of the model object is composed of a plurality of bones and a plurality of joints, the position (relative position) of the control point with respect to the joint is obtained by coordinate conversion using a coordinate conversion matrix. Further, when the front control point is set on the front side of the joint and the rear control point is set on the rear side of the joint, the control point calculation unit 116 changes the position of the front side control point according to the motion of the model object. Find the position of the point and the position of the back control point.

  The parameter calculation unit 118 calculates various parameters used for image processing and game processing. For example, in this embodiment, the texture storage unit 178 stores the wrinkle expression texture. Specifically, a plurality of wrinkle expressing textures having different texture patterns are stored for expressing wrinkles on the surface of the model object. Then, the parameter calculation unit 118 obtains composite parameters for a plurality of wrinkle expression textures based on the control points.

  For example, the parameter calculation unit 118 obtains a composite parameter based on the position of the control point obtained by coordinate conversion using the coordinate conversion matrix. Specifically, when the position of the control point in the world coordinate system is obtained by coordinate transformation using the coordinate transformation matrix, the synthesis parameter is obtained based on the position of the control point in the world coordinate system. Alternatively, the synthesis parameter is obtained based on the relative position of the control point with respect to the joint. When the first and second control points for wrinkle expression are set for the model object, the synthesis parameter is obtained based on the first and second control points. Specifically, a first distance (first distance parameter) between the first control point and another control point (joint) or a reference point (a representative point of the model object), a second control point, and the like A second distance (second distance parameter) from the control point or the reference point is obtained, and a synthesis parameter is obtained based on the obtained first and second distances. For example, a synthesis parameter is obtained based on the first and second distances themselves, or a synthesis parameter is obtained based on a function value having the first and second distance parameters as arguments. Further, for example, a synthesis parameter that changes in accordance with the ratio between the first and second distances can be obtained. Alternatively, when the control point calculation unit 116 obtains the position of the front control point and the position of the rear control point, the parameter calculation unit 118 obtains the first composite parameter based on the front control point, and performs the rear control. A second synthesis parameter is determined based on the points. Note that the synthesis parameter may be obtained based on the angle formed by the first and second straight lines connecting the control points.

  A texture coordinate setting unit (texture coordinate calculation unit) 119 performs texture coordinate setting processing (calculation processing). That is, texture coordinate setting processing for fetching the texel value of the wrinkle expression texture is performed. For example, the texture storage unit 178 stores the wrinkle expression texture as a volume texture from which texel values are fetched at the first, second, and third texture coordinates (U, V, and W coordinates). In other words, the wrinkle expression texture is stored in the volume texture setting mode. In this case, the texture coordinate setting unit 119 sets the third texture coordinate (W coordinate) of the volume texture based on the synthesis parameter obtained by the parameter calculation unit 118. For the first and second texture coordinates, U and V coordinates set at the vertices of the model object can be used.

  The image generation unit 120 performs drawing processing based on the results of various processes (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, model data including vertex data (vertex position coordinates, texture coordinates, color data, normal vector, α value, etc.) of each vertex of the model (object) is first input. Based on the vertex data included in the input model data, vertex processing (shading by a vertex shader) is performed. 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, according to the vertex processing program (vertex shader program, first shader program), vertex movement processing, coordinate conversion (world coordinate conversion, camera coordinate conversion), clipping processing, perspective processing, and other geometric processing are performed. On the basis of the processing result, the vertex data given to the vertex group constituting the object is changed (updated or adjusted). Then, rasterization (scan conversion) is performed based on the vertex data after the vertex processing, and the surface of the polygon (primitive) 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. The final drawing color of the constituent pixels is determined, and the drawing color of the perspective-transformed model is output (drawn) to the drawing buffer 174 (a buffer capable of storing image information in units of pixels; VRAM, rendering 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. As a result, an image that can be seen from the virtual camera (given viewpoint) in the object space is generated.

  The vertex processing and pixel processing are realized by hardware that enables polygon (primitive) drawing processing 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 image generation unit 120 performs geometry processing, hidden surface removal processing, α blending, texture mapping processing, and the like when drawing an object.

  In the geometry processing, processing such as coordinate conversion, clipping processing, perspective projection conversion, or light source calculation is performed on the object. Then, model data (positional coordinates of object vertices, texture coordinates, color data, normal vectors, α values, etc.) after geometry processing (after perspective projection conversion) is stored in the storage unit 170.

  As the hidden surface removal process, there is a hidden surface removal process by a Z buffer method (depth comparison method, Z test) using a Z buffer (depth buffer) in which a Z value (depth information) of a drawing pixel is stored. That is, when drawing pixels corresponding to the primitive of the object are drawn, the Z value stored in the Z buffer (Z plane of the drawing buffer) is referred to. Then, the Z value of the referenced Z buffer is compared with the Z value at the drawing pixel of the primitive, and the Z value at the drawing pixel is a Z value (for example, a small Z value) on the near side when viewed from the virtual camera. In some cases, the drawing process of the drawing pixel is performed and the Z value of the Z buffer is updated to a new Z value.

  α blending (α synthesis) is processing performed based on an α value (A value), and includes normal α blending, addition α blending, subtraction α blending, and the like. 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 translucency (equivalent to transparency and opacity) information, mask information, or bump information.

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

  In the present embodiment, the image generation unit 120 synthesizes a plurality of wrinkle expression textures with the synthesis parameter obtained by the parameter calculation unit 118, and maps the obtained synthesis texture to a model object (clothes, skin). A wrinkle image (wrinkle expression image) of the model object is generated. For example, when the parameter calculation unit 118 obtains the first synthesis parameter for the front control point and the second synthesis parameter for the rear control point, a plurality of wrinkle expression textures are generated by the obtained first synthesis parameter. By synthesizing and mapping the synthesized texture to the front side of the model object, a wrinkle image on the front side of the model object is generated. Further, a plurality of wrinkle expression textures are synthesized with the obtained second synthesis parameter, and the obtained synthesized texture is mapped to the rear side surface of the model object, thereby generating a wrinkle image on the rear side surface of the model object. The front side wrinkle expression texture and the rear side wrinkle expression texture may be different patterns of texture. In addition, when the texture coordinate setting unit 119 sets the first, second, and third texture coordinates for the volume texture, the image generation unit 120 is based on the first, second, and third texture coordinates. The wrinkle expression texture is mapped to the model object as a volume texture (synthetic texture).

  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. 2. Method of this Embodiment 2.1 Motion Processing In this embodiment, as shown in FIG. 2, a model object MOB (character) includes a plurality of part objects (waist 12, chest 14, neck 16, head 18, upper right arm 20, The right forearm 22, right hand 24, left upper arm 26, left forearm 28, left hand 30, right crotch 32, right shin 34, right foot 36, left crotch 38, left shin 40, and left foot 42). The positions and rotation angles (directions) of these part objects (parts) are the positions of the bones B0 to B19 (positions of the joints J0 to J15) and the rotation angles (the positions of the child bones relative to the parent bones) constituting the skeleton model. Relative rotation angle). Note that these bones and joints are virtual and are not actually displayed objects.

  In the present embodiment, bones (motion bones, joints, part objects) constituting the skeleton of the model object MOB have a parent-child (hierarchical) structure. For example, the parents of the bones B7 and B11 of the hands 24 and 30 are the bones B6 and B10 of the forearms 22 and 28, and the parents of the B6 and B10 are the bones B5 and B9 of the upper arms 20 and 26. The parents of B5 and B9 become the bone B1 of the chest 14, and the parent of B1 becomes the bone B0 of the waist 12. The parents of the bones B15 and B19 of the legs 36 and 42 are the bones B14 and B18 of the shins 34 and 40, the parents of the B14 and B18 are the bones B13 and B17 of the crotch 32 and 38, and the parents of the B13 and B17 are the waist 12 Bones B12 and B16.

  The motion data storage unit 179 stores the positions and rotation angles of these bones (part objects, joints) as motion data. Note that only the rotation angle of the bone may be included in the motion data, and the bone position (joint position) may be included in the model data of the model object.

  For example, it is assumed that the walking motion is composed of reference motions (motions in each frame) M0, M1, M2,. Then, the position or rotation angle of each bone in each of these reference motions M0, M1, M2,... MN is stored in advance as motion data. Then, for example, the position data and the rotation angle of each part object of the reference motion M0 are read out, and then the position and rotation angle of each part object of the reference motion M1 are read out. Thus, motion processing (motion playback) is realized.

  The motion data stored in the motion data storage unit 179 is generally obtained by motion capture or created by a designer. The motion data is represented by the position of the parent bone, the relative position of the child bone with respect to the rotation angle, and the relative rotation angle (rotation angle around three axes). Specifically, as shown in FIG. 3, rotation angles α, β, and γ around the X axis, the Y axis, and the Z axis of the child bone BMC with respect to the parent bone BMP are stored as motion data.

  Further, in FIG. 2, RP is a representative point of the model object MOB, and this RP is set at a position just below the waist (J0) (position of zero height), for example. In addition to the bones B1 to B19 in FIG. 2, auxiliary bones that assist the deformation of the model object by the motion bones may be provided.

2.2 Generation of wrinkle image by synthesis of wrinkle expression texture In the present embodiment, as shown in FIG. A plurality of wrinkle expression textures TEX1 and TEX2 are prepared. These wrinkle expressing textures TEX1 and TEX2 have different texture patterns. In the present embodiment, the wrinkle expression textures TEX1 and TEX2 are synthesized by the synthesis parameter obtained by the parameter calculation unit 118, and the resultant synthesized texture TEX12 is mapped to the model object, thereby generating a wrinkle image of the model object. For example, if the synthesis parameter is A, the synthesized texture can be expressed as TEX12 = A × TEX1 + (1−A) × TEX2. Note that the synthetic texture generation method is not limited to the method represented by such an expression. For example, various modifications such as independently controlling the synthesis rate (blend rate) of TEX1 and the synthesis rate (blend rate) of TEX2 are possible.

  In the present embodiment, at least one control point for wrinkle expression is set in the model object. For example, in FIG. 4, the control point C1 is set near the right shoulder (joint J4) of the model object, and the control point C2 (joint J7) is set near the left shoulder. A control point C3 is set near the left waist, and a control point C4 is set near the right waist.

  In the present embodiment, the synthesis parameter A of the wrinkle expression textures TEX1 and TEX2 is obtained based on the control points C1 to C4. For example, the positions of the control points C1 to C4 (for example, positions in the world coordinate system) are obtained by coordinate transformation using a coordinate transformation matrix used for motion processing, and the synthesis parameter A is obtained based on the obtained positions.

  The coordinate transformation matrix of each bone can be obtained from a rotation matrix and a translation vector matrix of each bone (each part object) constituting the skeleton. Here, the rotation matrix (matrix) is a matrix whose components are represented using, for example, the rotation angles α, β, γ (roll angles) around the X, Y, and Z axes described in FIG. . The translation vector matrix is a matrix for representing the position of each bone, for example. By using a coordinate conversion matrix obtained from the rotation matrix and the translation vector matrix, the vertex local coordinates of the part object following each bone can be converted into world coordinates.

  In FIG. 4, control points C1 and C2 (first and second control points) for wrinkle expression are set, and a composite parameter A is obtained based on the positions of these control points C1 and C2. That is, the distance L1 (first distance) between the control point C1 (first control point) and another control point C3 (or reference point), the control point C2 (second control point), and another control point C4. A distance L2 (second distance) from (or a reference point) is obtained. Then, the synthesis parameter A is obtained based on the obtained distances L1 and L2. For example, when F (L1, L2) is a function having L1 and L2 as arguments, the synthesis parameter can be expressed as A = F (L1, L2). With this A = F (L1, L2), the synthetic texture TEX12 can be obtained by an equation such as TEX12 = A × TEX1 + (1−A) × TEX2.

  For example, in FIGS. 5A and 5B, the positions of the control points C1, C2, and the like change due to the change in the motion of the model object.

  In FIG. 5A, the distance L1 between the control points C1 and C3 is shorter than the distance L2 between the control points C2 and C4. In this case, for example, the synthesis parameter A is increased so that the synthesis rate (blend rate) of the wrinkle expression texture TEX1 is larger than the synthesis rate of the wrinkle expression texture TEX2. By doing so, a wrinkle image in which the wrinkle of the wrinkle expression texture TEX1 is expressed more strongly than the wrinkle expression texture TEX2 is generated.

  In FIG. 5B, the distance L2 between the control points C2 and C4 is shorter than the distance L1 between the control points C1 and C3. In this case, for example, the synthesis parameter A is reduced so that the synthesis rate of the wrinkle expression texture TEX2 is larger than the synthesis rate of the wrinkle expression texture TEX1. By doing so, a wrinkle image in which the wrinkle of the wrinkle expression texture TEX2 is expressed more strongly than the wrinkle expression texture TEX1 is generated.

  In the present embodiment, the positions of the control points C1, C2, etc. change in conjunction with the motion change of the model object, and the distances L1, L2 between the control points also change. For example, when the right shoulder of the model object (character) running on the field goes forward and the left shoulder goes backward, the distance L1 becomes shorter and the distance L2 becomes longer as shown in FIG. Then, the synthesis parameter A is increased (the synthesis rate of TEX1 is increased), and a wrinkle image in which the wrinkle of the wrinkle expression texture TEX1 is strongly expressed is generated. Thereafter, the motion of the model object running on the field changes, and when the left shoulder of the model object goes forward and the right shoulder goes backward, the distance L2 becomes shorter and the distance L1 becomes longer as shown in FIG. Become. Then, the synthesis parameter A becomes smaller (the synthesis rate of TEX2 becomes smaller), and a wrinkle image in which the wrinkle expression texture TEX2 is strongly expressed is generated.

  In this way, when the motion changes such that the right shoulder and the left shoulder of the model object alternately come forward, the synthesis parameter A changes accordingly, and the influence of the wrinkle expression textures TEX1 and TEX2 also becomes stronger alternately. Animated expression of wrinkles is performed. Accordingly, it is possible to generate an image that looks as if the wrinkles of the clothes of the model object are changed in conjunction with the motion change of the model object. Therefore, real wrinkle expression can be realized by simple processing.

  An example of the wrinkle expression texture TEX1 is shown in FIG. 6, and an example of the wrinkle expression texture TEX2 is shown in FIG. The wrinkle expression texture TEX1 in FIG. 6 is a texture representing a wrinkle image when the distance L1 is short as shown in FIG. 5A, for example. The wrinkle expression texture TEX2 in FIG. 7 is a texture representing a wrinkle image when the distance L2 is short as shown in FIG. 5B, for example. In this way, the images of the textures TEX1 and TEX2 having different texture patterns appear alternately on the surface of the clothes of the model object, thereby realizing wrinkle animation expression. Note that the number of wrinkle expression textures prepared in the present embodiment is not limited to two, and may be three or more. These three or more wrinkle expression textures may be combined and mapped.

  FIG. 8 shows an example of a game image generated by the present embodiment, and FIG. 9 shows an enlarged view of the wrinkle portion. 8 and 9, the wrinkles on the surface of the shirt of the model object representing the soccer player are represented. For example, when the right shoulder of the model object goes forward and the left shoulder goes backward as shown in FIG. 8, the distance L1 becomes shorter and the distance L2 becomes longer as shown in FIG. Then, the synthesis parameter A is increased, and a wrinkle image in which the wrinkle of the wrinkle expression texture TEX1 in FIG. 6 is strongly expressed is generated. Thereafter, when the left shoulder of the model object goes forward and the right shoulder goes back, the distance L1 becomes shorter and the distance L2 becomes longer as shown in FIG. 5B, and the wrinkle of the wrinkle expression texture TEX2 shown in FIG. A wrinkle image that is more strongly expressed is generated. Therefore, it is possible to express a state in which the wrinkle pattern changes in conjunction with the running motion of the model object.

  Various calculation methods are possible for the synthesis parameter A. For example, in FIG. 10, the synthesis parameter A is represented by a function F (L1, L2) having distances L1, L2 as arguments. Specifically, the synthesis parameter A is a parameter that changes according to the ratio of the distances L1 and L2. That is, the synthesis parameter A can be expressed by a function G having an argument of H1 (L1) / {H1 (L1) + H2 (L2)}. Here, the function H1 is a function having L1 as an argument, and the function H2 is a function having L2 as an argument. For example, the synthesis parameter can be expressed as A = L1 / (L1 + L2).

  Specifically, when the distance L1 = L2, the synthesis parameter is A = 0.5. Therefore, in this case, a synthetic texture TEX12 is generated by synthesizing the wrinkle expression texture TEX1 in FIG. 6 and the wrinkle expression texture TEX2 in FIG. 7 at a ratio of 1: 1, and is mapped to the front side of the model object.

  Also, let L1max and L1min be the maximum and minimum values of the distance L1, and let L2max and L2min be the maximum and minimum values of the distance L2. Then, when L1 = L1min and L2 = L2max, the synthesis parameter is A = 1.0. Accordingly, the wrinkle expression texture TEX1 in FIG. 6 is mapped to the model object as the synthetic texture TEX12. When L1 = L1max and L2 = L2min, the synthesis parameter is A = 0. Accordingly, the wrinkle expression texture TEX2 in FIG. 7 is mapped to the model object as the synthetic texture TEX12. Note that the method for calculating the synthesis parameter A is not limited to that shown in FIG. 10, and various modifications can be made.

  In FIG. 4, four control points C1 to C4 are set for the model object. However, as shown in FIG. 11A, only two control points C1 and C2 are set, or only one control point is set. May be set. In FIG. 11A, the distance between the control point C1 and the reference point BP is L1, and the distance between the control point C2 and the reference point BP is L2. The reference point BP is a reference point for setting the distance L1 for the control point C1 and the distance L2 for the control point C2. As the reference point BP, the point of the joint J1 (or J0) in FIG. 2 or a point separated from the joint J1 by a given distance (for example, the navel of the character) can be used.

  Further, a control point C3 for wrinkle expression is set at the position of the reference point BP, the distance between the control points C1 and C3 is L1, and the distance between the control points C2 and C3 is L2, and is synthesized by the distances L1 and L2. The parameter A may be obtained.

  Further, not the distances L1 and L2, but a straight line SL1 connecting the control point C1 and the reference point BP (or other control point) and a straight line SL2 connecting the control point C2 and the reference point BP (or other control point). The composite parameter A may be obtained based on the angle θ.

  When the skeleton of the model object is composed of multiple bones and multiple joints, the relative position of the control point for a given joint among the multiple joints is obtained by coordinate conversion using the coordinate conversion matrix. Based on this relative position, the synthesis parameter A may be obtained.

  For example, in FIG. 11B, the joint J3 is the joint of the part object of the head 18 in FIG. 2, and changes the angle (α, β, γ in FIG. 3) formed by the child bone B3 with respect to the parent bone B2. By doing so, the movement (tilt) of the head 18 is controlled. The bones B20 and B21 in FIG. 11C are bones for controlling the movement of the eyebrows 51 and 52. That is, by controlling the angles (α, β, γ in FIG. 3) formed by the child bones B20, B21 with respect to the parent bone B2, the movement of the eyebrows 51, 52 is controlled.

  In FIG. 11B, control points CB1 and CB2 are set at the positions of the eyebrows 51 and 52 (for example, the joint positions of the eyebrows). Then, for example, the relative position of the control point CB1 with respect to the joint J3 is obtained by coordinate transformation using a coordinate transformation matrix obtained by the angle (motion data) formed by the bone B20 with respect to the bone B2. That is, the position of the control point CB1 in the local coordinate system with the joint J3 as the origin is obtained. Further, the relative position of the control point CB2 with respect to the joint J3 is obtained by coordinate transformation using a coordinate transformation matrix obtained by the angle (motion data) formed by the bone B20 with respect to the bone B2. That is, the position of the control point CB2 in the local coordinate system with the joint J3 as the origin is obtained.

  Then, based on the relative positions of the obtained control points CB1 and CB2, a wrinkle expression texture synthesis parameter A is obtained. For example, the composite parameter A is obtained based on at least one of the X coordinate, Y coordinate, or Z coordinate of the control points CB1, CB2 in the local coordinate system with the joint J3 as the origin.

  FIG. 12 shows an example of an image generated by the method shown in FIG. According to the method of FIG. 11B, when the position of the eyebrows moves due to the change in facial expression of the model object (character) in FIG. 12, the wrinkle image around the eyebrows also changes accordingly. That is, wrinkles of the skin similar to the wrinkles of the shirts of FIGS. 8 and 9 appear around the eyebrows, and the image of the wrinkles changes in conjunction with changes in the position of the eyebrows (changes in the bones B20 and B21). become. Thereby, the facial expression can be expressed more realistically, and the virtual reality of the player can be improved.

2.3 Front and rear control points In this embodiment, control points are set on the front side (front side) and rear side (back side) of the model object, and the first and second composite parameters are set by these control points. You may control independently.

  For example, in FIGS. 13A and 13B, the front control point CF1 is set on the front side of the joint J3 (the right shoulder joint) among the plurality of joints constituting the skeleton of the model object, and on the rear side of the joint J3. A rear control point CB1 is set. That is, the control point CF1 is set (arranged) at a position offset forward with respect to the joint J3, and the control point CB1 is set (arranged) at a position offset backward.

  13C and 13D, the front control point CF2 is set on the front side of the joint J7 (left shoulder joint), and the rear control point CB2 is set on the rear side of the joint J7. That is, the control point CF2 is set (arranged) at a position offset to the front side with respect to the joint J7, and the control point CB2 is set (arranged) at a position offset to the rear side.

  Then, the control point calculation unit 116 obtains the positions of the front control points CF1 and CF2 and the positions of the rear control points CB1 and CB2 whose positions change due to the change in the motion of the model object.

  Further, the parameter calculation unit 118 obtains a first composite parameter AF based on the front control points CF1, CF2, etc. as shown in FIG. Further, as shown in FIG. 14B, the second synthesis parameter AB is obtained based on the rear control points CB1, CB2, and the like.

  Then, the image generation unit 120 synthesizes the wrinkle expression textures TEX1 and TEX2 with the obtained synthesis parameter AF, and maps the obtained composite texture TEXF12 on the front side of the model object, so that the wrinkle image on the front side of the model object is obtained. Is generated. Further, the wrinkle expression textures TEX1 and TEX2 are synthesized with the obtained synthesis parameter AB, and the resultant synthesized texture TEXB12 is mapped to the rear side surface of the model object, thereby generating a wrinkle image on the rear side surface of the model object.

  For example, in FIG. 14A, the distance LF1 between the front control points CF1 and CF3 and the distance LF2 between the front control points CF2 and CF4 are obtained. Then, a synthesis parameter AF = F (LF1, LF2) having these distances LF1, LF2 as a function is obtained. The synthesis parameter AF is a parameter that changes according to the ratio of the distances LF1 and LF2, for example. As in the method of FIG. 11A, the distance between the front control point CF1 and the reference point BP may be LF1, and the distance between the front control point CF2 and the reference point BP may be LF2.

  In FIG. 14B, a distance LB1 between the rear control points CB1 and CB3 and a distance LB2 between the rear control points CB2 and CB4 are obtained. Then, a synthesis parameter AB = F (LB1, LB2) having these distances LB1, LB2 as a function is obtained. The synthesis parameter AB is a parameter that changes according to the ratio of the distances LB1 and LB2, for example. As in the method of FIG. 11A, the distance between the rear control point CB1 and the reference point BP may be LB1, and the distance between the rear control point CB2 and the reference point BP may be LB2.

  The synthetic texture TEXF12 obtained based on the synthetic parameter AF in FIG. 14A is mapped to the front side of the model object, and the synthetic texture TEXB12 obtained based on the synthetic parameter AB in FIG. If the mapping is performed on the rear side of the model object, the generated wrinkle images are different between the front side and the rear side of the model object, and a more realistic image can be generated.

  For example, when the right shoulder of the model object comes forward as shown in FIG. 8, on the front side of the model object, the distance LF1 between the front control point CF1 of the right shoulder and the front control point CF3 of the left waist becomes short, and the left shoulder The distance LF2 between the front control point CF2 and the right waist front control point CF4 becomes longer. Therefore, a wrinkle image in which the wrinkle expression texture TEX1 is strongly expressed is generated on the front side of the model object. On the other hand, on the back side of the model object, the distance LB1 between the back control point CB1 on the right shoulder and the back control point CB3 on the left waist becomes long, and the back control point CB2 on the left shoulder and the back control point CB4 on the right waist The distance LB2 between them becomes shorter. Accordingly, a wrinkle image in which the wrinkle expression texture TEX2 is strongly expressed is generated on the rear side of the model object.

  As a result, the generated wrinkle images are different between the front side surface and the rear side surface of the model object. Therefore, a more realistic image can be generated, and the virtual reality of the player can be further improved.

2.4 Volume Texture An image generation system (game device) may support a texture mapping function called volume texture (three-dimensional texture). Here, the volume texture is a three-dimensional collection of texels that can be used for drawing two-dimensional primitives such as polygons and lines. Three vertex texture coordinates (U, V, W) are required for each vertex of the primitive processed by the volume texture (three-dimensional texture). When the primitive is drawn by mapping this volume texture, the texel value (color value) of the volume texture is set to the pixel of each primitive according to the same rule as in the case of the conventional two-dimensional texture. This volume texture is prepared to express special effects such as fog and explosion. This volume texture can also be thought of as a texture that forms a volume of width × height × depth by stacking two-dimensional surfaces of width × height. The volume texture can have a mip level, and the size of each mip level is cut to half the size of the previous mip level.

  In order to refer to the texel value of the volume texture, three texture coordinates U, V, and W (first, second, and third texture coordinates) are required as shown in FIG. That is, the texture coordinate setting unit 119 sets the texture coordinates U, V, and W for fetching the texel value of the wrinkle expression texture.

  Specifically, a custom vertex type having three texture coordinates U, V, and W is designated for each vertex, a vertex buffer is created, and vertex data is set. Then, before drawing a primitive such as a polygon, the current texture is set as a volume texture and the primitive is drawn. The texture coordinates U and V correspond to texture coordinates for fetching (sampling) texel values of a normal two-dimensional texture.

  In the present embodiment, the third texture coordinate W of the volume texture is set based on the synthesis parameter A of the wrinkle expression textures TEX1 and TEX2. For example, the synthesis parameter A itself is set to the texture coordinate W, or a parameter obtained from the synthesis parameter A is set to the texture coordinate W. Based on the texture coordinates U, V, and W, a process of mapping the wrinkle expression texture as a volume texture to the model object is performed. In this way, as shown in FIG. 15, the synthesized texture TEX12 obtained by synthesizing the textures TEX1 and TEX2 is mapped to the model object.

  For example, in FIG. 15, the synthesized texture TEX12 is generated so that the synthesis rate (blend rate) of the texture TEX1 increases as the texture coordinate W increases, and the synthesis rate of the texture TEX2 increases as the texture coordinate W decreases. That is, the texel values of the textures TEX1 and TEX specified by the texture coordinates U and V are synthesized (texel interpolation) at a synthesis rate (blend rate) determined by the texture coordinates W and drawn on the primitive pixel. .

  If the synthetic texture TEX12 is obtained by using such a volume texture function, the program processing for generating the synthetic texture TEX12 can be omitted, and the volume texture function possessed by the hardware of the image generation system can be effectively utilized. Thus, the synthetic texture TEX12 can be mapped. That is, a wrinkle image can be generated by mapping the synthetic texture TEX12 to the model object by one texture mapping designating the texture coordinates U, V, W and the wrinkle expression textures TEX1, TEX2. Therefore, the processing load can be reduced and the processing speed can be increased.

  In the method of mapping the synthetic texture TEX12 for wrinkle expression to the model object using the volume texture as shown in FIG. 15, the synthetic parameter may be obtained based on the control point, but the synthetic parameter is obtained based on other elements. May be requested. For example, based on motion data (angle formed by bone, coordinate transformation matrix), a synthesis parameter is directly obtained, texture coordinates W are set based on the obtained synthesis parameter, and the obtained synthesized texture is mapped to a model object. May be.

2.5 Detailed Processing Example Next, a detailed processing example of this embodiment will be described with reference to the flowchart of FIG.

  First, it is determined whether or not it is a frame (1/60 second) update timing (step S1). If it is the frame update timing, the model object is moved (step S2). That is, the position and direction of the model object (representative point) are updated based on the speed and acceleration of the model object.

  Next, a coordinate transformation matrix (motion matrix) for motion processing of the model object is obtained based on the motion data (step S3). That is, a coordinate transformation matrix (matrix) is obtained based on motion data including the rotation angle of the child bone relative to the parent bone. Based on the coordinate conversion matrix of each joint, each control point is coordinate-converted to the world coordinate system (step S4). For example, the control points C1, C2, C3, and C4 in FIG. 4 are coordinate-transformed into the world coordinate system, and the position in the world coordinate system is obtained. Alternatively, the coordinates of the control points CF1, CB1, CF2, and CB2 in FIGS. 13A, 13B, 13C, and 13D are transformed using, for example, a coordinate transformation matrix for joints J4 and J7, and the position in the world coordinate system is obtained. Ask.

  Next, distances L1 and L2 between the control points are obtained (step S5). Then, based on the obtained distances L1 and L2, the texture coordinate W of the volume texture described in FIG. 15 is obtained (step S6). For example, W is obtained as a value corresponding to the ratio of the distances L1 and L2, such as W = L1 / (L1 + L2).

  Next, the U and V coordinates of each vertex of the model object are set to the first and second texture coordinates of the volume texture, and W is set to the third texture coordinate of the volume texture (step S7). Based on the texture coordinates (U, V, W), the wrinkle expression texture of FIGS. 6 and 7 is mapped to the model object as a volume texture, and the primitive of the model object is drawn (step S8).

3. Hardware Configuration FIG. 17 shows an example of a hardware configuration capable of realizing 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 required 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 cueing, mip mapping, fog processing, bilinear filtering, trilinear filtering, anti-aliasing, shading processing, and the like. When a programmable shader such as a vertex shader or a pixel shader is installed, the vertex data is created / changed (updated) and the drawing color of a pixel (or fragment) is determined according to the shader program. When an image for one frame is written in the frame buffer 922, the image is displayed on the display 912.

  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 is a work area for various processors. The DMA controller 970 controls DMA transfer between the processor and the memory. The DVD drive 980 (may be a CD drive) accesses a DVD 982 (may be a CD) 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. Also good. Alternatively, it may be realized by both hardware and a program.

  When the processing of each part of this embodiment is realized by both hardware and a program, a program for causing the hardware (computer) to function as each part 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.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings.

  Also, the control point setting method, control point calculation method, parameter calculation method, texture synthesis method, and texture mapping method are not limited to those described in the present embodiment, and methods equivalent to these are also included in the present invention. Included in the range.

  The present invention can be applied to various games. Further, the present invention is applied to various image generation systems such as a business game system, a home game system, a large attraction system in which a large number of players participate, a simulator, a multimedia terminal, a system board for generating game images, and a mobile phone. it can.

The example of a functional block diagram of the image generation system of this embodiment. Example of model object and skeleton structure. Explanatory drawing of parent-child relationship of bone. Explanatory drawing of the method of this embodiment. 5A and 5B are explanatory diagrams of the method of the present embodiment. Example of wrinkle expression texture. Example of wrinkle expression texture. The example of the image produced | generated by this embodiment. An example of an enlarged image of wrinkles. Explanatory drawing of the calculation method of a synthesis parameter. FIGS. 11A and 11B are explanatory diagrams of a modification of the method of the present embodiment. The example of the image produced | generated by this embodiment. FIGS. 13A, 13 </ b> B, 13 </ b> C, and 13 </ b> D are explanatory diagrams of a method for setting a front control point and a rear control point. FIGS. 14A and 14B are explanatory diagrams of a method for setting a front control point and a rear control point. Explanatory drawing of the method using a volume texture. The flowchart explaining the detailed process of this embodiment. Hardware configuration example.

Explanation of symbols

100 processing unit, 108 game calculation unit, 110 object space setting unit,
112 movement processing unit, 113 motion processing unit, 114 virtual camera control unit,
116 control point calculation unit, 118 parameter calculation unit, 119 texture coordinate setting unit,
120 image generation unit, 160 operation unit, 170 storage unit,
172 Main storage unit, 174 drawing buffer, 176 model data storage unit,
178 Texture storage unit, 179 Motion data storage unit,
180 information storage medium, 190 display unit, 192 sound output unit,
194 Portable information storage device, 196 communication unit

Claims (13)

A program for generating an image,
A motion processing unit that performs motion processing of a model object in which at least one control point for wrinkle expression is set;
A control point calculation unit for obtaining a position of the control point whose position changes due to a change in motion of the model object;
A texture storage unit for storing a plurality of wrinkle expressing textures having different texture patterns, which are textures for expressing the wrinkles on the surface of the model object;
Based on the control point, a parameter calculation unit for obtaining a composite parameter of a plurality of wrinkle expression textures;
As an image generation unit that generates a wrinkle image of a model object by synthesizing a plurality of wrinkle expression textures by the obtained synthesis parameter and mapping the obtained synthetic texture to the model object,
A program characterized by causing a computer to function. In claim 1,
The control point calculator is
By the coordinate transformation using the coordinate transformation matrix used for the motion processing, the position of the control point is obtained,
The parameter calculator is
A program for obtaining the synthesis parameter based on the position of the control point obtained by coordinate transformation. In claim 2,
The control point calculator is
By coordinate transformation using a coordinate transformation matrix, the position of the control point in the world coordinate system is obtained,
The parameter calculator is
A program for obtaining the synthesis parameter based on a position of the control point in the world coordinate system. In claim 2,
The control point calculator is
When the skeleton of the model object is composed of a plurality of bones and a plurality of joints, the relative position of the control point with respect to a given joint among the plurality of joints is obtained by coordinate transformation using a coordinate transformation matrix. Seeking
The parameter calculator is
A program for obtaining the synthesis parameter based on a relative position of the control point with respect to the given joint. In any one of Claims 1 thru | or 4,
First and second control points for wrinkle expression are set for the model object,
The parameter calculator is
A program for obtaining the synthesis parameter based on the positions of the first and second control points. In claim 5,
The parameter calculator is
A first distance between the first control point and another control point or reference point and a second distance between the second control point and another control point or reference point are obtained, and the obtained first distance is obtained. 1. A program for obtaining the synthesis parameter based on a first distance and a second distance. In claim 6,
The parameter calculator is
A program for obtaining the synthesis parameter that changes in accordance with a ratio of the first and second distances. In any one of Claims 1 thru | or 7,
When the skeleton of the model object is composed of a plurality of bones and a plurality of joints, an anterior control point is set on the front side of a given joint among the plurality of joints, and a rear side is placed on the back side of the given joint. Side control point is set,
The control point calculator is
Find the position of the front control point and the position of the rear control point whose position changes due to the change in the motion of the model object,
The parameter calculator is
Determining a first composite parameter based on the front control point, determining a second composite parameter based on the back control point;
The image generation unit
A plurality of wrinkle expressing textures are synthesized according to the obtained first synthesis parameter, and the obtained synthesized texture is mapped to the front side of the model object to generate a wrinkle image on the front side of the model object. In addition, a plurality of wrinkle expressing textures are synthesized by the second synthesis parameter, and the resultant synthesized texture is mapped to the back side of the model object, thereby generating a wrinkle image on the back side of the model object. program. In any one of Claims 1 thru | or 8.
As a texture coordinate setting unit for setting a texture coordinate for fetching the texel value of the wrinkle expression texture,
Make the computer work,
The texture storage unit
Storing the wrinkle representation texture as a volume texture from which texel values are fetched at the first, second, and third texture coordinates;
The texture coordinate setting unit
Based on the synthesis parameter, set the third texture coordinate of the volume texture;
The image generation unit
A program for performing a process of mapping a wrinkle expression texture as a volume texture to a model object based on the first, second, and third texture coordinates. A program for generating an image,
A texture storage unit for storing a plurality of wrinkle expressing textures, each of which is a texture for expressing wrinkles on the surface of the model object, the texture pattern of which is different;
A texture coordinate setting unit for setting a texture coordinate for fetching a texel value of the wrinkle expression texture;
A parameter calculation unit for obtaining a composite parameter of a plurality of wrinkle expression textures;
As an image generator that generates wrinkled images of model objects,
Make the computer work,
The texture storage unit
Storing the wrinkle representation texture as a volume texture from which texel values are fetched at the first, second and third texture coordinates;
The texture coordinate setting unit
Based on the synthesis parameter, set the third texture coordinate of the volume texture;
The image generation unit
A program for performing a process of mapping a wrinkle expression texture as a volume texture to a model object based on the first, second, and third texture coordinates.   A computer-readable information storage medium, wherein the program according to any one of claims 1 to 10 is stored. An image generation system for generating an image,
A motion processing unit that performs motion processing of a model object in which at least one control point for wrinkle expression is set;
A control point calculation unit for obtaining a position of the control point whose position changes due to a change in motion of the model object;
A texture storage unit for storing a plurality of wrinkle expressing textures having different texture patterns, which are textures for expressing the wrinkles on the surface of the model object;
Based on the control point, a parameter calculation unit for obtaining a composite parameter of a plurality of wrinkle expression textures;
An image generation unit that generates a wrinkle image of the model object by synthesizing a plurality of wrinkle expression textures according to the obtained synthesis parameter and mapping the obtained synthetic texture to the model object;
An image generation system comprising: An image generation system for generating an image,
A texture storage unit for storing a plurality of wrinkle expressing textures, each of which is a texture for expressing wrinkles on the surface of the model object, the texture pattern of which is different;
A texture coordinate setting unit for setting a texture coordinate for fetching a texel value of the wrinkle expression texture;
A parameter calculation unit for obtaining a composite parameter of a plurality of wrinkle expression textures;
An image generation unit that generates a wrinkle image of the model object,
The texture storage unit
Storing the wrinkle representation texture as a volume texture from which texel values are fetched at the first, second and third texture coordinates;
The texture coordinate setting unit
Based on the synthesis parameter, set the third texture coordinate of the volume texture;
The image generation unit
An image generation system that performs a process of mapping a wrinkle expression texture as a volume texture to a model object based on the first, second, and third texture coordinates.