JP4868586B2 - Image generation system, program, and information storage medium - Google Patents

Description

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

  In recent years, an image generation system that generates an image of an object such as a character arranged and set in a virtual three-dimensional space (object space) viewed from a virtual camera (a given viewpoint) has been put into practical use.

  Such an image generation system has been used in various systems as being able to experience virtual reality. For example, in an image viewed from a virtual camera in order to produce a sense of speed, the virtual camera There is known a method of changing a region in which a display object (object) is clearly drawn and a region in which the display object (object) is drawn in a blurred manner according to the moving speed of the object.

Specifically, as the moving speed of the virtual camera increases, this image generation system narrows the area where the display object is clearly drawn in the image, and clears the other areas (the boundaries of the color shade of the image). In this case, it is possible to generate an image that produces a sense of speed by simulating the visual field situation when the speed is increased by enlarging the area where the blurring process is performed without performing the process.
Japanese Patent No. 3444236

  However, in the image generation system as described above, although the effect of speed is produced by changing the blur area in the image, the process corresponding to the change in speed is performed for the area subjected to the blur process. Is not performed (the same processing is performed for the region where the blurring process is performed at any speed), and thus the difference in speed may not be accurately expressed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to change a blurring process according to the moving speed of a virtual camera to accurately express a sense of speed, an information storage medium, and an image generation To provide a system.

  (1) The present invention is an image generation system for generating an image visible from a virtual camera in an object space, the object space setting unit for setting an object in the object space, and the virtual camera based on predetermined control information A virtual camera control unit that controls the movement of the image, and a drawing unit that projects an object visible from the virtual camera onto a screen and draws an original image, and executes a predetermined filtering process on the original image, The rendering unit generates a polygon mesh in which vertices are arranged radially from representative points associated with the original image, and textures the original image for each vertex constituting the polygon mesh. Are associated with the first texture coordinates and based on a predetermined condition, A texture coordinate setting process for setting a second texture coordinate based on the shift amount, and a color acquired from the original image based on the second texture coordinate. The present invention relates to an image generation system configured to execute, as the predetermined filter process, a mesh drawing process for setting the color of each pixel of the polygon mesh associated with a first texture coordinate and drawing the polygon mesh. . The present invention also relates to a program that causes a computer to function as each of the above-described units and a computer-readable information storage medium that stores such a program.

  According to the present invention, a special polygon mesh in which an original image is associated as a texture is prepared, and filtering processing is performed by drawing while shifting texture coordinates of each vertex constituting the polygon mesh.

  As a result, according to the present invention, for example, when a gazing point is set for an object moving in an object space such as a racing game and the virtual camera follows the movement of the object, A feeling of speed (difference in speed such as high speed, medium speed, and low speed) can be accurately expressed by filtering.

  (2) In the image generation system, the program, and the information storage medium of the present invention, the drawing unit corresponds to each vertex of the polygon mesh in the polar coordinate system having the representative point as an origin in the predetermined filter processing. 3 texture coordinates are set, an interpolation coefficient setting process for setting an interpolation coefficient based on the third texture coordinates, and the first texture coordinates and the second texture coordinates are used as the interpolation coefficients. And a texture coordinate interpolation process for setting a fourth texture coordinate by linear interpolation based on the color, and in the mesh drawing process, a color acquired from the original image based on the fourth texture coordinate is obtained. , Setting as a color of each pixel of the polygon mesh associated with the first texture coordinates, It may be demarcating.

  In this way, the fourth texture coordinate is obtained using the third texture coordinate specified in the polar coordinate system on the basis of the first texture coordinate and the second texture coordinate, and the fourth texture coordinate is obtained. Since the polygon mesh is drawn with the color of the original image specified by the coordinates as the color of the pixel of the polygon mesh corresponding to the first texture coordinates, various deviations are reflected in the rotation direction around the representative point. Blur processing can be performed with a pattern. For this reason, the pattern of filter processing can be diversified, and a sense of speed according to the situation can be expressed.

  (3) Further, in the image generation system, the program, and the information storage medium of the present invention, the drawing unit performs the third texture coordinate from a random texture having a texel pattern in which colors are randomly arranged in the interpolation coefficient setting process. The color may be acquired based on the color and the interpolation coefficient may be set based on the luminance value of the acquired color.

  In this way, an irregular change can be given to the fourth texture coordinates, thus eliminating the inconvenience that the arrangement pattern of the vertices of the polygon mesh can be seen in the filtered image. Can do.

  (4) Further, in the image generation system, the program, and the information storage medium of the present invention, the drawing unit performs the first operation on the interpolation coefficient set based on the third texture coordinate in the interpolation coefficient setting process. Correction processing is performed based on pixel positions of the original image corresponding to one texture coordinate, and in the texture coordinate interpolation processing, the first texture coordinates and the second texture coordinates are calculated based on the interpolation coefficient after the correction processing. The texture coordinates may be linearly interpolated.

  In this way, by giving a change to the correction coefficient used when setting the fourth texture coordinates, for example, the intensity of the filtering process can be increased so that the vicinity of the target of the virtual camera in the original image can be clearly seen. Can be adjusted.

  (5) In the image generation system, the program, and the information storage medium of the present invention, the drawing unit determines the shift amount of the first texture coordinate based on the moving speed of the virtual camera in the texture coordinate setting process. You may make it set.

  In this way, for example, when the moving speed of the virtual camera is fast, the shift amount in the first texture coordinates is increased, and when the moving speed of the virtual camera is slow, the shift amount in the first texture coordinates. The shift amount of each pixel can be changed in accordance with the moving speed of the virtual camera, for example, by reducing.

  (6) In the image generation system, the program, and the information storage medium according to the present invention, the drawing unit increases the shift amount of the first texture coordinate as the moving speed of the virtual camera increases in the texture coordinate setting process. You may make it set large.

  In this way, it is possible to adjust the blurring effect of the original image by the filter processing so that the distortion of the original image becomes large when the moving speed of the virtual camera is high. For example, in an object space such as a race game When the virtual camera is made to follow the movement of the moving object, it is possible to accurately express the sense of speed when the object moves.

  (7) Further, in the image generation system, the program, and the information storage medium of the present invention, the drawing unit includes the representative point according to at least one of a movement amount and a movement direction of the virtual camera with respect to the screen in the mesh generation process. May be set.

  In this way, if the representative point that serves as a reference for the filter processing is moved so as to follow the movement of the virtual camera relative to the screen, a sense of speed can be obtained not only according to the movement amount of the virtual camera but also according to the moving direction of the virtual camera. It can be expressed accurately and the sense of reality can be further increased.

  (8) In the image generation system, the program, and the information storage medium of the present invention, the drawing unit includes, in the mesh generation process, each vertex of the polygon mesh including the original image from the representative point. They may be arranged at equal intervals on the radiation that reaches the outer periphery.

  In this way, there are areas where the vertices of the polygon mesh are densely arranged and coarsely arranged according to the movement of the virtual camera relative to the screen, so the speed feeling corresponding to the moving direction of the virtual camera is accurately expressed. Can also increase the sense of reality.

  (9) Further, in the image generation system, the program, and the information storage medium of the present invention, the drawing unit has a first texture coordinate corresponding to the vertex as the vertex farther from the representative point in the texture coordinate setting process. A large shift amount may be set.

  In this way, if the distortion is increased as the distance from the representative point increases, it is possible to reflect the visual characteristic that an image appears blurred as the part is closer to the virtual camera in the filter processing.

  (10) In the image generation system, the program, and the information storage medium of the present invention, the drawing unit shifts the first texture coordinate along the radiation from the representative point toward the vertex in the texture coordinate setting process. Thus, the second texture coordinates may be set.

  In this way, since it is possible to apply a filtering process that shifts the pixels of the original image radially to the original image, it is possible to accurately express how the speed increases toward a specific portion in the original image. be able to.

  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 of a player object (an example of a moving object, a player vehicle operated by the player, etc.), and its functions are lever, button, steering, microphone, touch panel type. It can be realized by a display or a housing. 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, a VRAM, or the like.

  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. That is, the information storage medium 180 stores 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 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.

  Note that a program (data) for causing a computer to function as each unit of the present embodiment is obtained from an information storage medium included in the host device (server) via the network and communication unit 196 (or the main memory of the storage unit 170). 172). Use of the information storage medium of 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. 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, GPU, DSP, etc.), ASIC (gate array, etc.), and programs.

  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.

  Based on the object data stored in the object data storage unit 172, the object space setting unit 110 displays objects such as cars, characters, buildings, stadiums, trees, pillars, walls, courses (roads), maps (terrain), and the like. A process for arranging and setting various objects (objects composed of primitives such as a polygon, a free-form surface, or a subdivision surface) in the object space is performed. That is, the position and rotation angle (synonymous with direction and direction) of the object in the world coordinate system are determined, and the determined rotation angle (about the X, Y, and Z axes) is determined at the determined position (X, Y, Z). Arrange objects at (rotation angle).

  The movement / motion processing unit 112 performs a movement / motion calculation (movement / motion simulation) of an object (such as a car, a character, or an airplane). That is, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), or the like, the object is moved in the object space, or the object is moved (motion, animation). ) Is performed. 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 that can be viewed from the virtual camera 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 an object (for example, a car, a character, or a ball) is photographed from behind using a virtual camera, the virtual camera position or rotation angle (virtual camera orientation) 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 (an example of predetermined control information) such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112. Alternatively, control may be performed such that the virtual camera is rotated at a predetermined rotation angle or moved along a predetermined movement path. In this case, the virtual camera is controlled based on virtual camera data (an example of predetermined control information) 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 from the object data storage unit 176, 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, 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 pixel to be configured is determined, and the drawing color of the perspective-converted object is output (drawn) to a drawing buffer 174 (a buffer capable of storing image information in pixel units) that is a 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. 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 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 drawing unit 120 performs geometry processing, texture mapping, hidden surface removal processing, α blending, 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. For example, in perspective projection conversion, an object arranged in the field of view (view volume) of a virtual camera is perspectively projected onto a screen set in front of the virtual camera. Then, object data (positional coordinates of object vertices, texture coordinates, color data (luminance data), normal vector, α value, etc.) after geometry processing (after perspective projection conversion) is stored in the object data storage unit 176. Is done.

  Texture mapping is a process for mapping a texture (texel value) stored in the storage unit 170 to an object. Specifically, the texture (surface properties such as color (RGB) and α value) is read from the storage unit 170 using texture coordinates or the like set (given) to 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, trilinear interpolation, etc. are performed as texel interpolation.

  As the hidden surface removal processing, hidden surface removal processing may be performed by a Z buffer method (depth comparison method, Z test) using a Z buffer 178 (depth buffer) in which a Z value (depth information) of a drawing pixel is stored. it can. That is, when the drawing pixel corresponding to the primitive of the object is drawn, the Z value stored in the Z buffer 178 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. If there is, the drawing process of the drawing pixel is performed and the Z value of the Z buffer 178 is updated to a new Z value.

  As the α blending, a translucent synthesis process (usually α blending, addition α blending, subtraction α blending, or the like) based on the α value (A value) is performed. For example, in the case of normal α blending, the following processes (1) to (3) are performed.

R _Q = (1−α) × R ₁ + α × R ₂ (1)
G _Q = (1−α) × G ₁ + α × G ₂ (2)
B _Q = (1−α) × B ₁ + α × B ₂ (3)
In addition, in the case of addition α blending, the following expressions (4) to (6) are performed. In the case of simple addition, α = 1 and the following formulas (4) to (6) are performed.

R _Q = R ₁ + α × R ₂ (4)
G _Q = G ₁ + α × G ₂ (5)
B _Q = B ₁ + α × B ₂ (6)
In the case of subtractive α blending, the processing of the following equations (7) to (9) is performed. In the case of simple subtraction, α = 1 and the following formulas (7) to (9) are processed.

R _Q = R ₁ −α × R ₂ (7)
G _Q = G ₁ −α × G ₂ (8)
B _Q = B ₁ −α × B ₂ (9)
Here, R ₁ , G ₁ , B ₁ are RGB components of an image (original image) already drawn in the frame buffer 172B or the frame buffer 174D, and R ₂ , G ₂ , B ₂ are the drawing buffer 174. Are RGB components of the image to be drawn. R _Q , G _Q , and B _Q are RGB components of an image obtained by α blending. 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.

  Further, in the present embodiment, the drawing unit 120 includes a filter processing unit 122.

  The filter processing unit 122 generates a substantially circular polygon mesh containing the original image drawn in the drawing buffer 174, and moves the virtual camera (viewpoint) while using the original image as a texture and corresponding to each vertex of the polygon mesh. Based on the speed, the original image can be filtered by drawing the texture coordinates corresponding to the vertices of the polygon mesh while shifting them radially from the representative points of the polygon mesh.

  Specifically, the filter processing 126 executes mesh generation processing, texture coordinate setting processing, interpolation coefficient setting processing, texture coordinate interpolation processing, mesh drawing processing, and the like as filter processing, and outputs the result of the filter processing to the drawing buffer 174. To do.

  In the mesh generation process, a process for generating a substantially circular polygon mesh in which vertices are arranged radially from representative points associated with the original image is performed.

  Specifically, a representative point is set at a position corresponding to the gazing point of the virtual camera on the screen based on the position (viewpoint position) and orientation (gaze direction) of the virtual camera. In this embodiment, the representative point can be set according to the movement amount of the virtual camera with respect to the screen. In this embodiment, a polygon mesh is generated by arranging vertices at equal intervals on the radiation from the representative point to the substantially circular outer periphery containing the original image. It is not always necessary to arrange the vertices at equal intervals. The distance between the vertices may be reduced as the distance from the representative point is increased, or the distance between the vertices may be increased as the distance from the representative point is increased.

  In the texture coordinate setting process, the first texture coordinates having the original image as the texture are associated with each vertex constituting the polygon mesh, and the first texture coordinates are shifted based on the moving speed of the virtual camera. The amount is set, and the second texture coordinates are set based on the set shift amount. In particular, in this embodiment, as the vertex farther from the representative point, the shift amount of the first texture coordinate associated with the vertex is set to be larger, and as the moving speed of the virtual camera is larger, the shift amount of the first texture coordinate is increased. Set a larger value.

  In the interpolation coefficient setting process, a third texture coordinate corresponding to each first texture coordinate at each vertex of the polygon mesh is set in a polar coordinate system with the representative point as the origin, and based on the third texture coordinate, Performs processing to set the interpolation coefficient. In the present embodiment, the color (R, G, B) is acquired based on the third texture coordinates from a random texture having a texel pattern in which the colors (R, G, B) are randomly arranged. An interpolation coefficient is set based on the luminance value of the R component. Of the colors sampled from the random texture, the luminance value of the G component or the luminance value of the B component may be set as an interpolation coefficient, or based on any combination of the luminance values of the R component, G component, and B component. Thus, the interpolation coefficient may be obtained by calculation.

  In the texture coordinate interpolation process, the fourth texture is obtained by linearly interpolating the first texture coordinate and the second texture coordinate associated with each vertex of the polygon mesh based on the interpolation coefficient set in the interpolation coefficient setting process. Performs processing to set coordinates.

  In the mesh drawing process, the polygon mesh is drawn by setting the color obtained from the original image based on the fourth texture coordinates as the color of each pixel of the polygon mesh associated with the first texture coordinates. The image subjected to the filtering process is drawn by. In the mesh drawing process, the color acquired from the original image based on the second texture coordinates is set as the color of each pixel of the polygon mesh associated with the first texture coordinates, and the polygon mesh is drawn. You may do it.

  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 according to this embodiment 2.1 Outline of filter processing according to this embodiment Next, an outline of the filter processing according to this embodiment will be described with reference to FIG.

  In this embodiment, with respect to each vertex constituting the polygon mesh associated with the original image as a texture (primitive vertex constituting the polygon mesh), the polygon coordinates are shifted while shifting the texture coordinates of each vertex according to the moving speed of the virtual camera. A method of drawing a mesh is adopted.

  For example, as shown in FIG. 2A, a polygon mesh PM in which vertices are arranged radially from the representative point A at substantially equal intervals using the original image as a texture is generated, and the position of each pixel constituting the original image is shifted. As shown in FIG. 2B, an image in which a sense of speed is realistically expressed by performing a filter process for drawing the polygon mesh PM while shifting the texture coordinates associated with each vertex of the polygon mesh PM. Can be generated.

  Specifically, a mesh generation process for generating a polygon mesh, a texture coordinate setting process for setting each texture coordinate for the generated polygon mesh, and an interpolation process for the set texture coordinate to set a new coordinate Various types of texture coordinate interpolation processing, interpolation coefficient setting processing for setting an interpolation coefficient used when performing the texture coordinate interpolation processing, and mesh drawing processing for drawing a polygon mesh based on finally set texture coordinates Filter processing is realized by performing the processing.

  By adopting such a method, the position of each pixel constituting the original image is shifted, and a blurring effect according to the moving speed of the virtual camera can be given to the original image. Also, if the moving speed of the virtual camera is fast, increase the pixel shift amount, and if the virtual camera moving speed is slow, decrease the pixel shift amount. The shift amount of each pixel is changed.

  Further, in the present embodiment, the shift of the radiation direction with respect to the representative point of the texture coordinate at each vertex of the polygon mesh is made to correspond to the moving speed of the virtual camera, and around the representative point of the texture coordinate using the polar coordinate system The degree of distortion can be adjusted.

  Therefore, according to the method of the present embodiment, for example, when the movement of the virtual camera follows the movement of the object moving in the object space such as a race game, the object moves as shown in FIG. The feeling of speed (difference in the moving speed of the virtual camera) can be accurately expressed according to the situation at the time.

2.2 Mesh Generation Processing Next, mesh generation processing according to the present embodiment will be described with reference to FIG.

  In the present embodiment, a position corresponding to a gazing point that determines the direction (gaze direction) of the virtual camera on the screen is set as a representative point, and apexes radially from the representative point toward the substantially circular outer periphery containing the original image. A method of generating a polygon mesh in which is arranged is employed.

  For example, as shown in FIG. 3A, when the representative point A (x, y) is associated with the vicinity of the center of the texture (original image), the four points of the texture from the representative point A (x, y) A circle passing through the corner is set as the outer periphery of the PM of the polygon mesh, and is divided into 48 radially from the representative point A toward the outer periphery (in the radiation direction), and the periphery of the representative point A (x, y) is set at predetermined angles. The polygon mesh PM having a substantially circular shape is generated by dividing into 16 parts. In the polygon mesh PM, primitives PR having the intersection points DP of the dividing lines as vertices are joined in a mesh shape.

In the present embodiment, for example, as shown in FIG. 3B, a representative point A (x ₁ , y ₁ ) located to the left of the outer peripheral center point O (x ₀ , y ₀ ) of the polygon mesh PM is displayed. If it is set, the representative point _{a (x 1, y} 1) reference is 48 divided in radial direction in a, and an array of 16 divided by vertices around the representative point _{a (x 1, y} 1) substantially A circular polygon mesh PM is generated. As described above, in the mesh generation processing according to the present embodiment, even when the representative point A is shifted from the center of the original image as the texture, the polygon mesh PM in which the vertices are arranged by performing a predetermined number of equal divisions is obtained. It is designed to generate. In particular, in this embodiment, the position of the representative point A is set according to the moving direction and moving amount of the virtual camera with respect to the screen (corresponding to the parallel movement component of the moving vector of the virtual camera with respect to the screen). Thus, a region where the vertices are densely arranged in the polygon mesh PM (region where the area of the primitive PR is small) and a region where the vertices are roughly arranged (region where the area of the primitive PR is large) can be generated. By doing in this way, with the method of this embodiment, it becomes possible to realize a filter process that can appropriately express a sense of speed along the moving direction of the virtual camera.

  Note that the mesh generation process is not limited to the case of generating a substantially circular polygon mesh that includes the original image using the original image as a texture as described above. If the original image can be included, a polygon mesh such as an elliptical shape can be used. May be generated.

2.3 Texture Coordinate Setting Process Next, the texture coordinate setting process of the present embodiment will be described with reference to FIG.

  In this embodiment, the original image is used as a texture, and each vertex constituting the polygon mesh is associated with the original image using a texture coordinate system in which UV coordinate values are normalized in the range of 0 to 1. A method of setting one texture coordinate is adopted.

Specifically, for example, as shown in FIG. 4 (A), any vertex _S B in the polygon mesh PM, with respect to _{S C,} the origin point of the upper left of the texture (i.e., (U, V) = (0, 0)) and on the basis of the texture coordinate system, _T1 B as first texture coordinate _(Ub 1, Vb ₁₎ is associated with the vertex _{S B, T1} C (Uc as first texture coordinates at the vertices _{S C 1} , Vc ₁ ).

  In this embodiment, the moving speed in the depth direction of the virtual camera (the Z-axis direction of the camera coordinate system) and the distance from the representative point to each vertex are set to 0 to 1 with respect to the first texture coordinates set for each vertex. An operation for obtaining a parameter normalized to the value range is executed to set a shift amount in the radiation direction of the first texture coordinates (direction from the representative point of the polygon mesh PM to the outer periphery). And the method of setting the 2nd texture coordinate corresponding to the 1st texture coordinate based on the set shift amount is adopted.

Specifically, for example, as shown in FIG. 4 (B), first the first texture coordinate associated with the texture coordinates T1 _B and vertex S _C associated with the vertex S _B of the polygon mesh PM A shift amount based on the value (Zv) ² obtained by normalizing the moving speed of the virtual camera with respect to T1 _{C and} squared and the distances L _B and L _C from the representative point A to the vertices S _B and S _C ΔT1 _B (ΔU _B , ΔV _B ), ΔT1 _C (ΔU _C , ΔV _C ) are set (see Formula 1), and second texture coordinates T2 _B and T2 _C are set (Formula 2). reference).

ΔT1 (ΔU, ΔV) = f ((Zv) ² × L) (Equation 1)
_{T2 (U 2, V 2)} = T1 (U 1, V 1) + ΔT1 (ΔU, ΔV) ··· ( Equation 2)
As described above, in the method of the present embodiment, the shift amount ΔT1 (ΔU, ΔV) of the first texture coordinate T1 is obtained in consideration of the moving speed in the depth direction of the virtual camera and the distance from the representative point A to the vertex. Accordingly, the faster the virtual camera moves in the depth direction, the larger the shift amount in the radiation direction of the first texture coordinate associated with the vertex, and the vertex farther from the representative point A becomes the first associated with the vertex. The second texture coordinate can be set so that the shift amount of the texture coordinate in the radiation direction becomes large.

In the method of this embodiment, the moving speed of the virtual camera in the depth direction (the direction from the viewpoint position toward the gazing point) is normalized, and the first value is determined according to the square value (Zv) ² of the normalized value. Although the texture coordinates of 2 fluctuate, the moving speed of the virtual camera in the depth direction can be normalized as follows.

  For example, taking a racing game as an example, when the virtual camera is controlled to follow a moving object such as a vehicle, the moving speed of the virtual camera in the depth direction is from 0 km / h to the speed per hour. When changing in the range of 350 km / h, 0 km / h to 100 km / h is associated with “0” to “1.0” and “1.0” from 100 km / h to 350 km / h. It can be normalized by clamping to the value of.

  Furthermore, the image generation system of the present embodiment sets the position of the second texture coordinate by increasing the shift amount of the first texture coordinate as the viewpoint moving speed increases.

  As described above, according to the method of the present embodiment, the distortion of the original image can be increased as the distance from the representative point increases, and the distortion of the original image increases as the moving speed of the virtual camera in the depth direction increases. Since the blurring effect can be adjusted, the difference in speed associated with the movement of the virtual camera, in particular, the difference in speed such as high speed, medium speed, and low speed can be accurately represented by the degree of distortion of the original image.

2.4 Interpolation Coefficient Setting Process Next, the texture setting process of this embodiment will be described with reference to FIGS. 5 and 6.

  In the present embodiment, in the polar coordinate system having the representative point determined in the mesh generation process as the origin (coordinate center), the third texture coordinate corresponding to the first texture coordinate indicating each vertex of the polygon mesh is set. At the same time, a method of setting an interpolation coefficient for interpolating between the first texture coordinate and the second texture coordinate based on the third texture coordinate is employed.

  In particular, in the present embodiment, a color is obtained from a random texture having a texel pattern in which colors are randomly arranged based on the third texture coordinates, and an interpolation coefficient is set based on the luminance value of the obtained color. It has become.

  That is, in the interpolation coefficient setting process, when the first texture coordinates and the second texture coordinates are synthesized, polar coordinates corresponding to the first texture coordinates are determined, and the interpolation coefficients are set using the polar coordinates. Therefore, when performing the blurring process on the original image, the sampling pattern of the original image in the filter process can be changed in various ways in consideration of the shift in the rotation direction around the representative point. Yes.

Specifically, in the polar coordinate system in which the representative point A is set to the origin (0, 0), the value of the U-axis component is the distance from the representative point A, and the value of the V-axis component is the angle around the representative point A. A third texture coordinate T3 (U ₃ , V ₃ ) is set for each vertex of the polygon mesh PM.

For example, as shown in FIG. 5, the third texture coordinates T3 _B (Ub ₃ , Vb ₃ ), T3 _C (Uc ₃ , Vc ₃ ) specified in the polar coordinate system are used for the vertices S _B and S _C of the polygon mesh PM. ) Is set, a texel in which colors are randomly arranged as shown in FIG. 6 based on the third texture coordinates T3 _B (Ub ₃ , Vb ₃ ) and T3 _C (Uc ₃ , Vc ₃ ). Colors (Rb, Gb, Bb) and (Rc, Gc, Bc) set in texels Pb and Pc corresponding to the third texture coordinates are acquired from a random texture having a pattern. Then, the luminance values Rb and Rc of the R component among the acquired colors are set as interpolation coefficients.

  In the present embodiment, when setting the interpolation coefficient, the luminance value of the R component among the RGB color components acquired based on the random texture is used. The brightness value of the B component may be used, or may be obtained from any combination of the brightness values of the respective color components.

  In the present embodiment, the case where a color is obtained from a random texture based on the third texture coordinates has been described as an example, but it is not always necessary to obtain a color from a random texture, and a texture having an arbitrary texel pattern Alternatively, the color may be acquired based on the third texture coordinates, and the interpolation coefficient may be obtained from the luminance value of the acquired color.

2.5 Texture Coordinate Interpolation Process Next, the texture coordinate interpolation process of this embodiment will be described.

  In the present embodiment, a method of setting the fourth texture coordinates by linearly interpolating the first texture coordinates and the second texture coordinates based on the interpolation coefficient set in the interpolation coefficient setting process is employed.

  Specifically, the interpolation set by the interpolation coefficient setting process as described above with respect to the first texture coordinate T1 and the second texture coordinate T2 associated with each vertex set by the texture coordinate setting process. The calculation shown in (Formula 3) is executed using the coefficient R, and the fourth texture coordinate T4 is set.

T4 (U4, V4) = T1 (U1, V1) x (1-R) + T2 (U2, V2) x R (Equation 3)
In the interpolation coefficient setting process described above, the interpolation coefficient R set using the random texture based on the third texture coordinate T3 is set at the pixel position of the original image corresponding to the first texture coordinate T1. Correction processing may be performed based on this.

  For example, when an object to be clearly seen by an observer is drawn below the center of the original image, the interpolation coefficient R is lower for pixels arranged below the center of the original image. The shift effect may be reduced by correcting and increasing the composition ratio of the first texture coordinates T1. Further, in this case, the pixel arranged above the center of the original image is corrected so that the interpolation coefficient R becomes higher and the composition ratio of the second texture coordinates T2 is increased, so that the shift effect is high. It may be made to become. In this way, by giving a change to the correction coefficient R used when setting the fourth texture coordinate T4, for example, the filtering process is performed so that the vicinity of the target of the virtual camera in the original image can be clearly seen. Since the intensity can be adjusted, even if the position of the representative point A of the polygon mesh PM is away from the object to be visually recognized, the blur effect is weakened in the vicinity of the object to be visually recognized. Hard to give stress.

  As described above, according to the method of the present embodiment, not only the shift according to the moving speed of the virtual camera but also the blurring process with various patterns reflecting the shift in the rotation direction around the representative point. It can be performed. For this reason, the pattern of filter processing can be diversified, and a sense of speed according to the situation can be expressed.

2.6 Mesh Drawing Processing Next, mesh drawing processing according to the present embodiment will be described.

  In the present embodiment, based on the fourth texture coordinate T4 set in the texture coordinate interpolation process, the color acquired from the texture of the original image is changed to the first texture coordinate T1 set in the texture coordinate setting process. Is used as a pixel color of the polygon mesh PM corresponding to the above, and a method of drawing the polygon mesh PM is adopted.

  Therefore, according to the method of the present embodiment, the effect of shifting the pixels constituting the original image in accordance with the moving speed of the virtual camera can be obtained, so the virtual camera can be used for objects moving in the object space such as a racing game. , The speed feeling when the object moves, in particular, the difference in speed such as high speed, medium speed or low speed can be accurately expressed by the blurring process.

3. Processing of the present embodiment Next, filter processing according to the present embodiment will be described with reference to FIG.

  First, when the original image is drawn (step S1), representative points are set based on the control information (position and orientation) of the virtual camera when the original image is constructed, and vertices are arranged radially with reference to the representative points. A polygon mesh is generated (step S2).

  Next, the first texture coordinates are set by associating each vertex constituting the generated polygon mesh with the texture texel based on the original image (step S3).

  Next, the shift amount of the first texture coordinate is set for each vertex of the polygon mesh using the moving speed in the virtual camera and the distance from the representative point to each vertex as parameters, and the second texture coordinate corresponding to each vertex is set. Set (step S4).

  Next, third texture coordinates corresponding to each vertex of the polygon mesh are set in the texture coordinates in the polar coordinate system having the representative point determined in the mesh generation process as the origin (step S5).

  Next, based on the third texture coordinates, the color of the texel is sampled from a random texture having a texel pattern in which colors are randomly arranged, and the luminance value of the R component of the sampled color is set as an interpolation coefficient (step) S6).

  Next, for each vertex of the polygon mesh, the first texture coordinates and the second texture coordinates are linearly interpolated based on the interpolation coefficient set in the process of step S5, and the fourth texture coordinates are set. (Step S7).

  Finally, for each vertex of each polygon mesh, the color is sampled from the texture of the original image based on the fourth texture coordinates, and the polygon mesh is drawn while setting the color of each pixel of the polygon mesh (step S9). .

  The present invention is not limited to the one 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.

  Also, each process of the filter process is not limited to that described in the present embodiment, and techniques equivalent to these are also included in the scope of the present invention.

  For example, in the filter processing according to the present embodiment, the color of each pixel of the polygon mesh is obtained from the texture of the original image based on the second texture coordinates without performing the interpolation coefficient setting processing and the texture coordinate interpolation processing. May be drawn. Also, instead of performing the texture coordinate interpolation process, the color acquired from the original image based on the first texture coordinate and the color acquired from the original image based on the second texture coordinate are converted into the interpolation coefficient setting process. The polygon mesh may be drawn by performing linear interpolation based on the set interpolation coefficient. However, in this case, since processing in units of pixels increases, considering processing load, it is possible to perform filter processing at higher speed by adopting texture coordinate interpolation processing that requires processing in units of vertices.

  Further, the filter processing method of the present embodiment charges a special parameter (increases and updates) when a so-called drifting state (predetermined moving state) in which a corner of a moving object is slid, and the operation unit It can be applied to an image generation system in which a special parameter is consumed and a special parameter is consumed (used) to accelerate a moving body and advance a race advantageously. In such an image generation system, when the consumption amount (use amount) of a charged special parameter is determined according to the type of a specific operation on the operation unit, the polygon mesh is based on the consumption amount of the special parameter. A shift amount of the first texture coordinate associated with each vertex may be set.

  Further, the present invention can be applied to various games. The present invention is applied to various image generation systems such as an arcade 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. Applicable.

The functional block diagram of the image generation system of this embodiment. The figure for demonstrating the outline | summary of the filter process of this embodiment. The figure for demonstrating the mesh production | generation process of this embodiment. The figure for demonstrating the texture coordinate setting process of this embodiment. The figure for demonstrating the interpolation factor setting process of this embodiment. The example of the random texture used for the interpolation coefficient setting process of this embodiment. The flowchart which shows the example of the filter process of this embodiment.

Explanation of symbols

100 processing unit,
110 Object space setting unit, 112 Movement / motion processing unit,
114 virtual camera control unit, 120 drawing unit, 122 filter processing unit,
130 sound generator,
160 operation unit, 170 storage unit, 172 main storage unit, 174 drawing buffer,
176 Object data storage unit, 178 Z buffer,
180 information storage medium, 190 display unit, 192 sound output unit,
194 Portable information storage device, 196 communication unit

Claims (15)

A program for generating an image visible from a virtual camera in an object space,
An object space setting section for setting an object in the object space;
A virtual camera control unit that performs movement control of the virtual camera based on predetermined control information;
Projecting an object visible from the virtual camera onto a screen to draw an original image, and causing a computer to function as a drawing unit that executes a predetermined filtering process on the original image,
The drawing unit
A mesh generation process for generating a polygon mesh in which vertices are radially arranged from representative points associated with the original image;
Corresponding to each vertex constituting the polygon mesh is a first texture coordinate having the original image as a texture, and setting a shift amount of the first texture coordinate based on a predetermined condition, A texture coordinate setting process for setting the second texture coordinates based on the shift amount;
A mesh for drawing the polygon mesh by setting the color acquired from the original image based on the second texture coordinates as the color of each pixel of the polygon mesh associated with the first texture coordinates Drawing process,
Is executed as the predetermined filtering process ,
In the mesh generation process, the drawing unit
A program that sets the representative point according to at least one of a movement amount and a movement direction of the virtual camera with respect to the screen . In claim 1,
In the mesh generation process, the drawing unit
The representative point is set according to at least one of a parallel movement component of the movement amount of the virtual camera with respect to the screen and a parallel movement component of the movement direction of the virtual camera with respect to the screen. In claim 1 or 2,
In the mesh generation process, the drawing unit
A program characterized in that the representative point is set according to a parallel movement component of a movement vector of the virtual camera with respect to a screen. In any one of Claims 1-3,
In the mesh generation process, the drawing unit
A program characterized in that the representative point is set at a position shifted from a center point of the original image in accordance with at least one of a movement amount and a movement direction of the virtual camera with respect to the screen. A program for generating an image visible from a virtual camera in an object space,
An object space setting section for setting an object in the object space;
A virtual camera control unit that performs movement control of the virtual camera based on predetermined control information;
Projecting an object visible from the virtual camera onto a screen to draw an original image, and causing a computer to function as a drawing unit that executes a predetermined filtering process on the original image,
The drawing unit
A mesh generation process for generating a polygon mesh in which vertices are radially arranged from representative points associated with the original image;
Corresponding to each vertex constituting the polygon mesh is a first texture coordinate having the original image as a texture, and setting a shift amount of the first texture coordinate based on a predetermined condition, A texture coordinate setting process for setting the second texture coordinates based on the shift amount;
A mesh for drawing the polygon mesh by setting the color acquired from the original image based on the second texture coordinates as the color of each pixel of the polygon mesh associated with the first texture coordinates Drawing process,
Is executed as the predetermined filtering process,
In the predetermined filtering process, the drawing unit
An interpolation coefficient setting process for setting a third texture coordinate corresponding to each vertex of the polygon mesh in a polar coordinate system having the representative point as an origin, and setting an interpolation coefficient based on the third texture coordinate; ,
Texture coordinate interpolation processing for linearly interpolating the first texture coordinates and the second texture coordinates based on the interpolation coefficient to set fourth texture coordinates;
As well as
In the mesh drawing process, the color acquired from the original image based on the fourth texture coordinates is set as the color of each pixel of the polygon mesh associated with the first texture coordinates, A program characterized by drawing a polygon mesh. In claim 5 ,
In the interpolation coefficient setting process, the drawing unit
A color is acquired from a random texture having a texel pattern in which colors are randomly arranged based on the third texture coordinates, and the interpolation coefficient is set based on a luminance value of the acquired color. program. In claim 5 or 6 ,
The drawing unit
In the interpolation coefficient setting process, a correction process is performed on the interpolation coefficient set based on the third texture coordinate based on the pixel position of the original image corresponding to the first texture coordinate,
In the texture coordinate interpolation processing, the first texture coordinates and the second texture coordinates are linearly interpolated based on the interpolation coefficient after the correction processing. In any of the claims 1-7,
The drawing unit, in the texture coordinate setting process,
A program for setting a shift amount of the first texture coordinate based on a moving speed of the virtual camera. In claim 8 ,
The drawing unit, in the texture coordinate setting process,
A program for setting a shift amount of the first texture coordinate to be larger as the moving speed of the virtual camera is higher. In any of the claims 1-9,
In the mesh generation process, the drawing unit
A program characterized in that the vertices of the polygon mesh are arranged at equal intervals on radiation extending from the representative point to a substantially circular outer periphery containing the original image. In any one of Claims 1-10 ,
The drawing unit, in the texture coordinate setting process,
The program characterized by setting the shift amount of the first texture coordinate corresponding to the vertex as the vertex farther from the representative point. In any one of claims 1 to 11,
The drawing unit, in the texture coordinate setting process,
A program characterized in that the second texture coordinates are set by shifting the first texture coordinates along the radiation from the representative point toward the vertex. An information storage medium readable to a computer, the information storage medium characterized by storing a program according to any one of claims 1 to 12. An image generation system for generating an image visible from a virtual camera in an object space,
An object space setting section for setting an object in the object space;
A virtual camera control unit that performs movement control of the virtual camera based on predetermined control information;
A drawing unit that projects an object visible from the virtual camera onto a screen to draw an original image, and executes a predetermined filter process on the original image;
Including
The drawing unit
A mesh generation process for generating a polygon mesh in which vertices are radially arranged from representative points associated with the original image;
Corresponding to each vertex constituting the polygon mesh is a first texture coordinate having the original image as a texture, and setting a shift amount of the first texture coordinate based on a predetermined condition, A texture coordinate setting process for setting the second texture coordinates based on the shift amount;
A mesh for drawing the polygon mesh by setting the color acquired from the original image based on the second texture coordinates as the color of each pixel of the polygon mesh associated with the first texture coordinates Drawing process,
Is executed as the predetermined filtering process ,
In the mesh generation process, the drawing unit
The image generation system , wherein the representative point is set according to at least one of a movement amount and a movement direction of the virtual camera with respect to the screen . An image generation system for generating an image visible from a virtual camera in an object space,
An object space setting section for setting an object in the object space;
A virtual camera control unit that performs movement control of the virtual camera based on predetermined control information;
A drawing unit that projects an object visible from the virtual camera onto a screen to draw an original image, and executes a predetermined filter process on the original image;
Including
The drawing unit
A mesh generation process for generating a polygon mesh in which vertices are radially arranged from representative points associated with the original image;
Corresponding to each vertex constituting the polygon mesh is a first texture coordinate having the original image as a texture, and setting a shift amount of the first texture coordinate based on a predetermined condition, A texture coordinate setting process for setting the second texture coordinates based on the shift amount;
A mesh for drawing the polygon mesh by setting the color acquired from the original image based on the second texture coordinates as the color of each pixel of the polygon mesh associated with the first texture coordinates Drawing process,
Is executed as the predetermined filtering process,
In the predetermined filtering process, the drawing unit
An interpolation coefficient setting process for setting a third texture coordinate corresponding to each vertex of the polygon mesh in a polar coordinate system having the representative point as an origin, and setting an interpolation coefficient based on the third texture coordinate; ,
Texture coordinate interpolation processing for linearly interpolating the first texture coordinates and the second texture coordinates based on the interpolation coefficient to set fourth texture coordinates;
As well as
In the mesh drawing process, the color acquired from the original image based on the fourth texture coordinates is set as the color of each pixel of the polygon mesh associated with the first texture coordinates, An image generation system characterized by drawing a polygon mesh.