JP4408681B2 - Program, information storage medium, and image generation system - Google Patents

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 seen from a given viewpoint (virtual camera) in an object space (virtual three-dimensional space) in which model objects such as characters are arranged and set is known. It is popular as a place to experience so-called virtual reality.

In this image generation system, texture mapping is used to express background dirt and the like. Specifically, the background dirt is expressed by drawing a polygon to which the dirt pattern texture is mapped. However, with this method, when the dirt range increases, the number of polygons to be drawn increases accordingly, and the processing load increases. Therefore, it was difficult to express a wide range of dirt.
JP-A-2001-76174

  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 capable of realizing paint expression on a model object with a small processing load. There is.

  The present invention relates to an image generation system that generates an image that can be viewed from a given viewpoint in an object space, a display area in which a drawing image is cleared by frame update, and a paint area in which the drawing image is not cleared by frame update; And a drawing unit that draws an image in the area of the storage unit, and the drawing unit paints a paint image in the paint area that remains without clearing the paint texture in the previous frame. This is related to an image generation system that generates a paint texture in the current frame and draws a display model object in the display area while performing texture mapping of the generated paint texture. The present invention also relates to a program that causes a computer to function as each of the above-described units. The present invention also relates to a computer-readable information storage medium that stores (records) a program that causes a computer to function as each unit.

  According to the present invention, the paint texture is generated by drawing the paint image in the paint area where the drawing image is not cleared by the frame update. A display image (game image, frame image) is generated by drawing the display model object in the display area while performing texture mapping of the generated paint texture. In this way, it is only necessary to draw the paint image in the current frame in the paint area, so that the processing load can be reduced. The paint texture in the current frame is generated by drawing a paint image in the area for painting that remains without clearing the paint texture generated in the previous frame. Accordingly, it is possible to realize an image expression in which the range of dirt, bullet holes, etc. gradually expands with a small processing load.

  The generated paint texture may be mapped directly to the display model object together with other textures by the multi-texture mapping method, or the paint texture may be mapped to a separately prepared paint model object. .

  In the image generation system, the program, and the information storage medium according to the present invention, the storage unit further includes a texture region in which a texture to be mapped to the display model object is stored, and the drawing unit includes the texture region. A texture is mapped to a display model object, the paint texture is mapped to a paint model object in which the shape of the display model object is simplified, and a texture in the texture area is mapped, and the paint texture The paint model object to which is mapped may be drawn in the display area.

  In this way, even in an image generation system that does not support the multi-texture mapping function in the narrow sense, it is possible to realize a paint expression that attaches dirt, bullet holes, etc. to the model object. Also, by simplifying the shape of the paint model object, it is possible to save the memory capacity used.

  In the image generation system, the program, and the information storage medium according to the present invention, the paint area of the storage unit corresponds to the first to Nth surfaces of the paint model object or the display model object. N regions, and the drawing unit generates paint textures generated in the first to Nth regions of the paint region as the first to Nth paint model objects or display model objects. You may make it map to a surface.

  In this way, even when the paint or display model object has the first to Nth surfaces, the paint expression for painting the paint image on each of these surfaces can be realized by a simple process.

  In the image generation system, the program, and the information storage medium according to the present invention, the paint area of the storage unit is a first bottom area corresponding to the first bottom face of the paint model object or the display model object. A second bottom surface area corresponding to a second bottom surface at a position higher than the first bottom surface of the paint model object or the display model object, and the drawing unit includes the paint region The paint texture generated in the first and second bottom surface areas may be mapped to the first and second bottom surfaces of the paint model object or the display model object.

  In this way, it is possible to effectively prevent a situation where a paint image that should not be painted on the second bottom surface is painted on the second bottom surface.

  In the image generation system, program, and information storage medium according to the present invention, a hit check model object or display model object in which the shape of the display model object is simplified, and a hit check unit that performs hit check processing with a primitive, A drawing position determining unit that determines the drawing position of the paint image based on the hit position of the primitive obtained by hit check processing (the computer functions as a hit check unit and a drawing position determining unit), The paint image may be drawn at the determined drawing position.

  In this way, when a primitive hits a hit check or display model object, a display model object image in which a paint image is painted at a position corresponding to the hit position can be generated. Expression can be realized.

  Further, the present invention is an image generation system for generating an image that can be viewed from a given viewpoint in an object space, wherein the storage unit includes a display area and a paint area, and the paint image is drawn in the paint area. A drawing unit that draws a display model object in the display area while generating a paint texture and performing texture mapping of the generated paint texture, and a hit check model that simplifies the shape of the display model object A hit check unit for performing a hit check process with an object or a display model object and a primitive, and a drawing position determining unit for determining a paint image drawing position based on the hit position of the primitive obtained by the hit check process Concerning image generation system including. The present invention also relates to a program that causes a computer to function as each of the above-described units. The present invention also relates to a computer-readable information storage medium that stores (records) a program that causes a computer to function as each unit.

  According to the present invention, the drawing position is determined based on the hit position obtained by the hit check process, and the paint image is drawn at the determined drawing position. Therefore, when a primitive hits a hit check or display model object, a display model object image in which a paint image is painted at a position corresponding to the hit position can be generated, and a realistic image expression can be realized. .

  In the image generation system, the program, and the information storage medium according to the present invention, the drawing unit performs texture mapping for mapping the generated paint texture by enlarging or reducing, and the drawing position determining unit performs hit check processing. The drawing position of the paint image or the drawing position and size of the paint image may be determined based on the obtained hit position of the primitive and the scaling ratio of the paint texture.

  In this way, a consistent paint expression can be realized even when the size of the paint area is fixed for simplification of address management.

  In the image generation system, program, and information storage medium according to the present invention, the scale factor of the paint texture is a model object in which the shape of the display model object is simplified and the paint texture is mapped to the paint model object Or you may make it identify based on the size data of the model object for a display.

  In the image generation system, program, and information storage medium according to the present invention, the size data may be data obtained from the maximum value and the minimum value of each vertex coordinate of the paint model object or the display model object.

  In the image generation system, the program, and the information storage medium according to the present invention, the drawing position determination unit may perform a paint image based on the movement position of the primitive that moves along the plane of the hit check model object or the display model object. The drawing position may be determined, and the drawing unit may draw the paint image at the determined drawing position corresponding to the movement position of the primitive.

  In this way, it is possible to generate an image that looks as if the paint image is moving along the surface of the display model object, thereby improving the effect.

  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, a button, a steering, a microphone, a touch panel display, a housing, 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 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 this embodiment is distributed from the information storage medium of the host device (server) to the information storage medium 180 (storage unit 170) via the network and communication unit 196. May be. 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 storage unit 170 as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs.

  The processing unit 100 includes an object space setting unit 110, a movement / motion processing unit 112, a particle processing unit 113, a viewpoint control unit 114, a hit check unit 116, a drawing position determination unit 118, a drawing unit 120, and a sound generation unit 130. Some of these may be omitted.

  The object space setting unit 110 is a model object representing objects such as characters, cars, trees, columns, walls, buildings, maps (terrain) (objects composed of primitive surfaces such as polygons, free-form surfaces, or subdivision surfaces). ) Is set in the object space. In other words, the position and rotation angle (synonymous with orientation and direction) of the model object in the world coordinate system are determined, and the rotation angle (rotation angle about the X, Y, and Z axes) is determined at that position (X, Y, Z). Place the model object with.

  The movement / motion processing unit 112 performs a movement / motion calculation (movement / motion simulation) of a model object (car, airplane, character, etc.). That is, the model object (moving object) is moved in the object space or the model object is moved based on operation data, a program (movement / motion algorithm), or various data (motion data) input by the player through the operation unit 160. Perform processing to move (motion, animation). Specifically, a simulation for sequentially obtaining movement information (position, rotation angle, speed, or acceleration) and motion information (position or rotation angle of each part object) of each model object every frame (1/60 seconds). Process. The frame is a unit of time for performing model object movement / motion processing (simulation processing) and image generation processing.

  The particle processing unit 113 generates, moves, or extinguishes particles (primitives in a broad sense) for expressing an irregularly shaped display object (for example, flame, smoke, water, explosion) whose shape is deformed. Process. Specifically, a process of randomly changing the generation amount, generation position, movement state (speed, acceleration, etc.) or lifetime of particles (for example, flame particles and smoke particles) generated from a given generation position is performed.

  The viewpoint control unit 114 performs a virtual camera (viewpoint) control process for generating an image that can be seen from a given (arbitrary) viewpoint in the object space. Specifically, a process for controlling the position (X, Y, Z) or the rotation angle (rotation angle about the X, Y, Z axes) of the virtual camera (process for controlling the viewpoint position and the line-of-sight direction) is performed.

  For example, when a model object is photographed from behind using a virtual camera, the position or rotation angle (the direction of the virtual camera) of the virtual camera is controlled so that the virtual camera follows changes in the position or rotation of the model object. 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 / motion processing unit 112. Alternatively, the virtual camera may be rotated at a predetermined rotation angle while being moved along a predetermined movement route. In this case, the virtual camera is controlled based on virtual camera data for specifying the position (movement path) and rotation angle of the virtual camera.

  The hit check unit 116 performs hit check processing between the model object and the primitive (particle, polygon, free-form surface, etc.). This hit check process is realized, for example, by obtaining the intersection of the surface of the model object and the movement trajectory of the primitive. The model object to be hit-checked with the primitive may be a hit check model object or a display model object.

  Here, the display model object is a model object (an object composed of a plurality of part objects) that is actually displayed on the screen. For example, a game such as a background, a character, a car, a motorcycle, a ship, a spaceship, or a robot. This is a model object that represents a display object that appears in. The hit check model object (hit volume, hit box) is prepared separately from the display model object for hit check, and is a model object in which the shape of the display model object is simplified. For example, the hit check model object has a smaller number of primitive faces (number of polygons) than the display model object. Further, in the model object for display, a portion that is precisely expressed by a large number of primitive surfaces is also simplified and expressed by a small number of primitive surfaces in the model object for hit check.

  The size of the hit check model object and the arrangement position in the object space are substantially the same as the size and arrangement position of the display model object. However, in order to prevent flickering of the display screen or the like, the hit check model object is desirably arranged at a position shifted, for example, in the upward direction (Y direction) from the display model object.

  The drawing position determination unit 118 performs processing for determining the drawing position of a paint image representing dirt, bullet holes, and the like. Specifically, the drawing position of the paint image is determined based on the hit position between the model object (hit check and display model object) and the primitive (particle) obtained by the hit check processing by the hit check unit 116. To do. More specifically, the drawing position of the paint image (paint texture) is determined based on the hit position of the primitive, the scaling ratio of the paint texture described later, the normal vector of the surface of the model object hit by the primitive, and the like. .

  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. In the case of generating a so-called three-dimensional game image, first, geometric processing such as coordinate transformation (world coordinate transformation, camera coordinate transformation), clipping processing, or perspective transformation is performed, and drawing data ( The position coordinates, texture coordinates, color data, normal vector, α value, etc.) of the vertexes of the primitive surface are created. Based on the drawing data (primitive surface data), the model object (one or a plurality of primitive surfaces) after perspective transformation (after the geometry processing) is drawn in the display area 172. Thereby, an image that is visible from a given viewpoint (virtual camera) in the object space is generated.

  Specifically, both the display area 172 and the paint area 174 of the storage unit 170 configured by a VRAM or the like are areas in which image information can be stored in units of pixels. A display area 172 corresponding to a so-called frame buffer is an area where a frame image (game image, display image) to be displayed in each frame is generated, and frame update (for example, every 1/60 seconds, which is one frame). This is an area where the image is cleared (refreshed). This clearing of the image is realized, for example, by writing a black image on the entire screen. On the other hand, the paint area 174 used for generating the paint texture is an area where the image is not cleared by the frame update. A part of the paint area 174 may be cleared by frame update.

  Then, the drawing unit 120 draws the paint image (dirt image) in the paint region 174 that remains without clearing the paint texture (paint image) generated up to the previous frame. Generate a paint texture. The display model object is drawn in the display area 172 while performing texture mapping of the generated paint texture. In this way, a frame image (game image, display image) in the current frame is generated.

  The drawing unit 120 includes a texture mapping unit 122 and an α synthesis unit 124. The texture mapping unit 122 performs processing for mapping the paint texture generated in the paint area 174 and the texture (texel value) stored in the texture area 176 to the model object. Specifically, the texture (surface properties such as color and α value) is read from the paint area 174 and the texture area 176 using the texture coordinates set (given) at the vertices of the model object (primitive surface). Then, a texture that is a two-dimensional image or pattern is mapped to a model object. In this case, processing for associating pixels and texels, bilinear interpolation (texel interpolation), and the like are performed. Thus, the texture mapping unit 122 performs mapping of the paint texture generated in real time by drawing the paint image in the paint region 174.

  There are various texture mapping methods for the texture mapping unit 122. For example, in the first method, the texture (background texture, background texture) in the texture area 176 is mapped to the display model object, and the generated paint texture (overlay texture, dirt texture, bullet hole texture) is used as the paint model object. Map. Then, the display model object to which the texture in the texture area is mapped and the paint model object to which the paint texture is mapped are drawn in the display area 172. On the other hand, in the second method, the texture stored in the texture area 176 and the generated paint texture are mapped to the display model object by so-called multi-texture mapping. Then, the display model object subjected to the multi-texture mapping is drawn in the display area 172.

  The α synthesis unit 124 performs α synthesis processing (α blending, α addition, α subtraction, or the like) based on the α value (A value). For example, when the α composition is α blending, the following composition processing is 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)
On the other hand, when α composition is addition α blending, the following composition processing is 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)
Here, R ₁ , G ₁ , B ₁ are RGB components of the image already drawn in the display area 172 and the paint area 174, and R ₂ , G ₂ , B ₂ are the display area 172 and This is the RGB component of the image to be drawn in the paint area 174. 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.

  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. Next, the method of this embodiment will be described with reference to the drawings.

2.1 Generation of Paint Texture In the present embodiment, the following technique is used to express dirt or the like attached to the background (floor, wall) of the game image. For example, in FIG. 2, a display area (display VRAM area) is an area that is cleared (refreshed) by frame update, and is an area in which a display model object DOB (model object representing a background such as a room) is drawn. On the other hand, the paint area (paint VRAM area) is an area that is not cleared by frame update, and is an area in which a paint texture is generated in real time.

  In this embodiment, the paint texture in the current frame is generated by drawing the paint image in the paint area where the paint texture in the previous frame remains. Then, while performing texture mapping of the generated paint texture, the display model object DOB is drawn in the display area, thereby generating an image in which dirt (paint texture) is attached to the background (display model object).

  More specifically, as shown in FIG. 2, the paint area corresponds to the surfaces SF1 to SF5 (first to Nth surfaces in a broad sense) of the display model object DOB (or a paint model object POB described later). Regions PR1 to PR5 (first to Nth regions in a broad sense). For example, when the display model object represents the background of a room, the surfaces SF1, SF2, SF3, SF4, and SF5 are the floor (bottom surface in a broad sense), the north side wall, the east side wall, the south side wall, and the west side, respectively. It is a wall (side in the broad sense).

  In this embodiment, a paint image is drawn in each of the regions PR1 to PR5 of the paint region. In this case, the drawing position of the paint image is determined based on the hit position of the primitive (particle representing dirt) obtained by hit check processing, as will be described later. For example, when it is determined that the dirt effect primitive hits (collides) with the floor of the room, a paint image (dirt image) is drawn in the region PR1 corresponding to the floor surface SF1. Similarly, when it is determined that the dirt effect primitive hits the north side wall of the room, a paint image is drawn in the region PR2 corresponding to the surface SF2 of the north side wall. Drawing of a paint image is realized by drawing a primitive surface (polygon) to which a texture such as dirt is mapped in a paint area.

  The paint texture generated in each of the regions PR1 to PR5 of the paint region is mapped to each surface SF1 to SF5 of the display model object DOB (paint model object POB). Thereby, the expression which stains the background of a room etc. is realizable.

  In particular, in the present embodiment, the paint area is not cleared (refreshed) by the frame update. Therefore, the paint image drawn in the previous frame (one or more frames before) remains in each of the paint regions PR1 to PR5, and the current paint image is α-combined (α blending, addition). (α blending) etc. Therefore, each time a primitive (particle) hits a surface, the surface is contaminated and the contamination range is expanded. In this embodiment, the dirt state is maintained unless intentionally deleted, and the processing load hardly increases even if the dirt range is increased. In addition, it is possible to continuously expand the dirt range as if painting with a brush. In addition, a full-color pattern can be pasted on the background as if it were a stamp, and an effect that a liquid such as blood adheres and the room becomes dirty can be expressed with a small processing load.

  For example, as a technique for expressing dirt, a technique for directly drawing a dirt polygon onto which a dirt texture (bullet hole texture) is mapped in a display area is conceivable. However, with this method, the number of dirt polygons increases as the dirt range widens, and the drawing load increases. On the other hand, in the present embodiment, since the image in the paint area remains without being cleared by the frame update, there is an advantage that the drawing load hardly increases even if the dirt range is widened.

  In FIG. 2, the number of regions PR1 to PR5 set as the paint region is five, but the present embodiment is not limited to this. For example, an area for a ceiling surface may be further provided. Alternatively, as shown in FIG. 3, a region PR1 (first bottom region) corresponding to the floor 1 (first bottom surface in a broad sense) and a floor 2 (second region in a broad sense) located higher than the floor 1 A region PR6 (second bottom surface region) corresponding to the bottom surface may be provided.

  For example, if the room has a mezzanine floor, the following problem arises unless the region PR6 corresponding to the floor 2 (surface SF6) is provided. That is, when a dirty paint image is drawn in the region PR1 corresponding to the lower floor (surface SF1), there is a problem that the paint image is painted on the floor 2 (surface SF6) which is the middle floor. If the region PR6 corresponding to the floor 2 (surface SF6) is provided as shown in FIG. 3, such a problem can be prevented.

  Examples of game images generated by this embodiment are shown in FIGS. In order to facilitate understanding of the technique of the present embodiment, a state where a paint image is drawn in the paint area is shown on the right side of the game image.

  In FIG. 4, liquid (blood or the like) ejected from the character's body flows on the floor of the room, which makes the floor dirty. In this case, the liquid is expressed by particles (primitives), hit check processing (collision determination processing) between the particles and the floor is performed, and a hit position (collision position) is obtained. Based on the obtained hit position, the drawing position of the paint area indicated by A1 in FIG. 4 is determined. More specifically, the drawing position is determined based on the hit position, the scaling ratio of the paint texture, and the normal vector of the surface (polygon) on which the particle hits. For example, when the direction of the normal vector of the surface (polygon) hit by the particle is upward (Y direction), it is determined that the drawing position is in the region PR1 corresponding to the floor. Then, the drawing position indicated by A1 in FIG. 4 is obtained by multiplying the coordinate value of the hit position by a value corresponding to the scaling ratio of the paint texture.

  Since all the paint areas are cleared in the initial state, the image of the paint area in the initial state is in a transparent state. In A1 of FIG. 4, a paint image representing liquid stain is drawn at the drawing position indicated by A1 in the transparent paint area, and a paint texture is generated. Then, by mapping the generated paint texture to a model object (display model object or paint model object), as shown in FIG. 4, it is possible to generate a game image in which the floor is stained with liquid.

  FIG. 5 is a game image after a plurality of frames have elapsed from FIG. In FIG. 5, the contamination range is enlarged as compared with FIG. In this case, in this embodiment, as shown by A2 in FIG. 5, the paint image (for example, A1 in FIG. 4) in the previous frame is not cleared but is held in the paint area and remains. Therefore, in the frame of the game image of FIG. 5, it is only necessary to draw the paint image to be drawn in that frame, so that the processing load can be reduced as compared with the method of drawing all the dirt polygons in all the frames.

  FIG. 6 shows a game image after a plurality of frames have elapsed from FIG. In FIG. 6, as shown by A3, the dirt range of the floor 1 is further expanded compared to FIG. Also, as shown in A4 and A5, paint images are also drawn in the regions PR5 and PR6 corresponding to the west side wall and the floor 2. By mapping the paint textures generated in these regions PR1, PR5, and PR6 to the floor 1, the west side wall, and the floor 2, an image in which dirt is attached to the floor 1, the west side wall, and the floor 2 can be generated. In A4 of FIG. 6, since the normal vector direction of the surface (polygon) on which the particle hits is eastward (see FIG. 3), the drawing position is determined to be in the region PR5 corresponding to the west side wall. Yes.

  FIG. 7 is a game image after a plurality of frames have elapsed from FIG. In FIG. 6, as indicated by A6, A7, and A8, the images of the regions PR1, PR5, and PR6 corresponding to the floor 1, the west side wall, and the floor 2 are retained without being erased even if the frame is updated. Further, as indicated by A9, a paint image is also drawn in the region PR4 corresponding to the south side wall. By mapping the paint texture generated in these areas PR1, PR4, PR5, and PR6 to floor 1, south side wall, west side wall, and floor 2, dirt adheres to floor 1, south side wall, west side wall, and floor 2 Images can be generated. In FIG. 7A9, since the direction of the normal vector of the surface on which the particle hits is north (see FIG. 3), the drawing position is determined to be in the region PR4 corresponding to the south side wall.

  As described above, according to the present embodiment, it is possible to realize an image expression in which dirt is freely attached to a floor or each wall of a room with a small processing load.

2.2 Paint Model Object In this embodiment, a paint model object POB as shown in FIG. 8 is prepared as a model object for mapping the paint texture generated by the method described with reference to FIGS. . This paint model object POB is a drawing model object for pasting a dirt pattern on the wall or floor of a room. In the game, the paint model object POB is transparent and cannot be seen at first, but when dirt is attached, the part appears on the screen. .

  The paint model object POB has a shape close to that of the display model object DOB (background model). Specifically, the number of polygons is reduced compared to the display model object DOB, and the shape of the DOB is simplified. For example, since dirt does not adhere to the entrance or pillar of the room, the shape of the portion is omitted and the shape is simplified. In order to prevent flickering due to interference between polygons, the paint model object POB is arranged at a position shifted upward by a given distance from the background display model object DOB.

  In the production stage of the paint model object POB, the temporary texture is mapped to the POB. This temporary texture is, for example, a monochromatic texture with different colors between the regions PR1 to PR6. The temporary texture for the floor 1 is mapped to the floor surface at the bottom of the paint model object POB, and the temporary texture for the floor 2 is mapped to the upper floor surface. Moreover, the temporary texture for each wall surface is mapped to each wall surface. For example, a rectangle specified by the maximum value and the minimum value of vertices on the XZ plane is assumed when the paint model object POB is viewed from directly above. Then, the temporary texture for the floor 1 is mapped so as to project onto the rectangle, and the texture coordinates (UV) of each vertex of the plurality of polygons are set. Further, on each of the east, west, north, and south wall surfaces, a rectangle specified by the maximum value and the minimum value of the vertices on the XY (ZY) plane is assumed when the paint model object POB is viewed from the front, the back, and the side. And the temporary texture for each wall surface is mapped so that it may project on the rectangle, and the texture coordinate (UV) of each vertex of a some polygon is set.

  During the game process, mapping is performed by designating the address of the paint area (paint VRAM area) instead of the texture address of the temporary texture. By doing this, instead of the temporary texture, the paint texture generated in real time in the paint area is mapped to the paint model object.

2.3 Hit Check Model Object In this embodiment, a hit check model object HOB as shown in FIG. 9 is prepared as a model object for determining the drawing position of the paint image. The hit check model object HOB has a simplified shape of the DOB or POB by reducing the number of polygons compared to the display model object DOB or the paint model object POB. The hit check model object HOB is produced by using the shape of the paint model object POB after completion. However, in order to reduce the calculation of hit check processing (collision determination), the number of polygons is reduced by combining polygons divided for drawing clips. In addition, the number of polygons is reduced by approximating minute irregularities such as stairs to a slope shape. In addition, the hit check is unnecessary for the portion where the dirt does not adhere, so the shape of the portion is omitted or simplified.

  In the present embodiment, the sizes of the areas PR1 to PR6 in the paint area shown in FIGS. 2 and 3 are fixed. By using a fixed size in this way, the storage capacity of the storage unit (VRAM) can be saved and address management can be simplified. On the other hand, the size of the model objects (painting and display model objects POB and DOB) varies depending on the game stage (room). Accordingly, the ratio between the size of each of the regions PR1 to PR6 and the size of each surface of the model object differs depending on the game stage.

  Therefore, in the present embodiment, the paint texture generated in real time is enlarged or reduced and mapped to the model object (POB or DOB). Specifically, as shown in FIG. 10A, the paint texture generated in the region PR1 is enlarged or reduced at the enlargement / reduction ratio SR1 on the surface SF1 (floor 1) of the room 1 (game stage 1). To do. On the other hand, on the surface SF1 of the room 2 (game stage 2), the paint texture generated in the region PR1 is enlarged or reduced at the enlargement / reduction ratio SR2 and mapped. In this way, the paint texture can be mapped without contradiction even when the areas PR1 to PR6 of the paint area have a fixed size. Note that the enlargement / reduction ratio may be set independently in the vertical direction and the horizontal direction.

  The drawing position of the paint image in the paint area is determined by the hit position of the particle (primitive) on the surface of the model object, the scaling ratio (including data corresponding to the scaling ratio) of the paint texture in FIG. Determine based on. For example, in FIG. 10B, the location indicated by B1 of the surface SF1 of the model object is determined as the hit position of the particle. When the drawing position shown in B2 is determined from the hit position shown in B1, the drawing position is determined using the scaling ratio of the paint texture. Whether the drawing position is in the region PR1 to PR6 can be determined based on the normal vector of the surface on which the particle hits. In this embodiment, for example, a paint polygon (sprite) in which the dirt texture shown in FIG. 10C is mapped at the drawing position B2 is drawn, thereby drawing a paint image and generating a paint texture. At the time of this drawing, the size of the paint image (painting polygon) is also changed according to the enlargement / reduction ratio of the paint texture. For example, when mapping is performed with a greatly enlarged paint texture, the paint image is also drawn with a greatly enlarged image. By doing so, the size of the dirt pattern can be made constant even if the game stage changes.

  The enlargement / reduction ratio of the paint texture can be specified based on the size data (paint size data) of the model object (POB or DOB). That is, when the size of the model object is large, the enlargement / reduction ratio increases, and when the size of the model object is small, the enlargement / reduction ratio also decreases.

  FIG. 11A shows an example of model object size data. This size data is data obtained from the maximum value and the minimum value of each vertex coordinate of the model object (POB or DOB). More specifically, the X coordinate maximum value, minimum value, Y coordinate maximum value, minimum value, Z coordinate maximum value, minimum value for all vertices of the model object are calculated in advance and converted into table data. It is. For example, the cube of FIG. 11B composed of the vertices VX1 to VX8 becomes a cube (bounding volume) that includes the model object (POB or DOB). By using such size data, the paint texture scaling ratio in each room (each game stage) can be easily obtained.

2.4 Application Example In FIG. 12A, when a particle representing a liquid hits a wall, an effect expression is made so that the liquid attached to the wall appears to flow down. This kind of presentation is controlled so that the particle of the effect moves slowly toward the bottom of the wall after hitting the wall, and the paint image (dirt texture) reduced in size than usual is continuously mapped. This can be achieved by drawing. More specifically, the drawing position of the paint image is determined based on the moving position of the particle (primitive) that moves along the surface of the model object (HOB or DOB). Then, by rendering the paint image at the determined rendering position corresponding to the particle movement position, it is possible to realize the effect expression shown in FIG.

  Also, in FIG. 12B, when the game character steps over an object containing liquid, the effect expression that the liquid spreads radially from the center of the object and the dirt adheres to the floor is realized. The effect expression of FIG. 12B can also be realized by determining the drawing position of the paint image based on the movement position of the particles moving along the surface of the model object, and drawing the paint image at the drawing position.

3. Processing of this Embodiment Next, a detailed processing example of this embodiment will be described with reference to the flowchart of FIG. First, an effect generation process including a plurality of particles is performed (step S1). Specifically, for example, when a weapon hits a character, particles representing liquid are generated from the hit position. In this case, the moving direction, moving speed, and life of the particles are determined based on random numbers.

  Next, a hit check (collision determination) between the hit check model object (FIG. 9) and each particle is performed, and the paint area is determined based on the hit position, the scale ratio (size data) of the paint texture, and the normal vector of the hit surface. The drawing position (texture coordinate position) of the paint image on (VRAM) is obtained (step S2, FIGS. 10A and 10B). Then, a polygon to which the dirt pattern texture (FIG. 10C) is mapped is drawn at the obtained drawing position to generate a paint texture (step S3).

  Next, a display model object (background model) to which the background texture of the texture area is mapped is drawn in the display area (VRAM) (step S4). Then, the paint model object (FIG. 8) to which the paint texture is mapped is drawn in the display area (VRAM) (step S5). By doing in this way, a game image as shown in FIGS. 4-7 can be produced | generated.

4). Hardware Configuration FIG. 14 shows an example of a hardware configuration capable of realizing this embodiment. The main processor 900 operates based on a program stored in a CD 982 (information storage medium), a program downloaded via the communication interface 990, a program stored in the ROM 950, or the like, and includes game processing, image processing, sound processing, and the like. Execute. 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 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 CD drive 980 accesses a CD 982 in which programs, image data, sound data, and the like are stored. The communication interface 990 performs data transfer with the outside via a network (communication line, high-speed serial bus).

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

  The present invention is not limited to that described in the above embodiment, and various modifications can be made. For example, terms (particles, terms) cited as broad or synonymous terms (primitives, first to Nth surfaces, first to Nth regions, bottom surfaces, side surfaces, primitive surfaces, etc.) in the description or drawings. Surfaces SF1 to SF6, regions PR1 to PR6, floors, walls, polygons, and the like) can be replaced with terms having a broad meaning or the same meaning in other descriptions in the specification or the drawings.

  The paint texture generation method and the mapping method are not limited to those described in the present embodiment, and methods equivalent to these methods are also included in the scope of the present invention. In this embodiment, the case where the display model object is a background model object such as a room has been described. However, the display model object may be a model object of a moving display object such as a character or a car.

  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 a game image, and a portable terminal. it can.

It is an example of a functional block diagram of the image generation system of this embodiment. It is explanatory drawing of the production | generation method of a paint texture. It is explanatory drawing of the production | generation method of a paint texture. It is an example of the game image produced | generated by this embodiment. It is an example of the game image produced | generated by this embodiment. It is an example of the game image produced | generated by this embodiment. It is an example of the game image produced | generated by this embodiment. It is an example of the model object for painting. It is an example of a model object for hit check. 10A to 10C are explanatory diagrams of a drawing position determination method. 11A and 11B are explanatory diagrams of size data. 12A and 12B are explanatory diagrams of application examples of the present embodiment. It is a flowchart of the specific process of this embodiment. It is a hardware structural example.

Explanation of symbols

DOB display model object, POB paint model object,
Model object for HOB hit check,
SF1 to SF6 plane, PR1 to PR6 region 100 processing unit, 110 object space setting unit, 112 movement / motion processing unit,
113 Particle processing unit, 114 Viewpoint control unit, 116 Hit check unit,
118 drawing position determination unit, 120 image generation unit, 122 texture mapping unit,
124 α synthesis unit, 130 sound generation unit, 160 operation unit, 170 storage unit,
172 Display area, 174 Paint area, 176 Texture area 180 Information storage medium, 190 Display section,
192 sound output unit, 194 portable information storage device, 196 communication unit

Claims (11)

A program for generating an image that can be viewed from a given viewpoint in an object space,
A storage unit having a display area in which a drawn image is cleared by frame update, and a paint area in which the drawn image is not cleared by frame update;
As a drawing unit for drawing an image in the area of the storage unit,
Make the computer work,
The drawing unit
The paint texture in the current frame is generated by drawing the paint image in the paint area where the paint texture in the previous frame remains without being cleared. A program for drawing a display model object in the display area while performing mapping. In claim 1,
The storage unit
A texture area in which a texture to be mapped to the display model object is stored;
The drawing unit
A texture model in the texture area is mapped to a display model object, the paint texture is mapped to a paint model object in which the shape of the display model object is simplified, and the texture model in the texture area is mapped. And a paint model object to which the paint texture is mapped is drawn in the display area. In claim 1 or 2,
The area for painting in the storage unit is
The first to Nth areas corresponding to the first to Nth surfaces of the paint model object or the display model object;
The drawing unit
A program for mapping paint textures generated in the first to Nth areas of the paint area on the first to Nth surfaces of a paint model object or a display model object. In claim 3,
The area for painting in the storage unit is
A first bottom surface area corresponding to the first bottom surface of the paint model object or the display model object, and a second bottom surface at a position higher than the first bottom surface of the paint model object or the display model object. A corresponding second bottom area,
The drawing unit
A program that maps the paint texture generated in the first and second bottom surface areas of the paint area to the first and second bottom surfaces of a paint model object or a display model object. . In any one of Claims 1 thru | or 4,
A hit check unit that performs hit check processing of a hit check model object or a display model object with a simplified shape of a display model object and a primitive;
As a drawing position determination unit that determines the drawing position of the paint image based on the hit position of the primitive obtained by the hit check process,
Make the computer work,
The drawing unit
A program characterized by drawing a paint image at a determined drawing position. Oite to claim 5,
The drawing unit
Perform texture mapping to map the generated paint texture by enlarging or reducing it,
The drawing position determination unit
A program which determines a drawing position of a paint image or a drawing position and size of a paint image based on a hit position of a primitive obtained by hit check processing and a scaling ratio of the paint texture. In claim 6 ,
The scaling ratio of the paint texture is
A program that is a model object obtained by simplifying the shape of a display model object and is specified based on size data of a paint model object or a display model object to which the paint texture is mapped. In claim 7 ,
The size data is data obtained from the maximum value and the minimum value of each vertex coordinate of a paint model object or a display model object. In any of claims 5 to 8 ,
The drawing position determination unit
Based on the movement position of the primitive that moves along the surface of the hit check model object or display model object, the drawing position of the paint image is determined,
The drawing unit
A program that draws a paint image at a determined drawing position corresponding to the movement position of a primitive. A computer-readable information storage medium, wherein the program according to any one of claims 1 to 9 is stored. An image generation system for generating an image that is visible from a given viewpoint in an object space,
A storage unit having a display area in which a drawn image is cleared by frame update, and a paint area in which the drawn image is not cleared by frame update;
A drawing unit for drawing an image in the area of the storage unit,
The drawing unit
The paint texture in the current frame is generated by drawing the paint image in the paint area where the paint texture in the previous frame remains without being cleared. An image generation system, wherein a display model object is drawn in the display area while mapping.

Images