JP4806578B2 - 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 viewed from a virtual camera (a given viewpoint) in an object space (virtual three-dimensional space) in which objects such as characters and cars are arranged and set is known. It is very popular for experiencing so-called virtual reality. Taking an image generation system capable of enjoying a racing game as an example, a player operates the own vehicle using an operation unit such as a game controller, and enjoys the game by competing with other vehicles operated by other players. .

  Such an image generation system employs a technique in which all backgrounds are represented by three-dimensional objects and drawn regardless of whether the background is a distant view or a close-up view.

However, according to this method, it is necessary to perform a three-dimensional operation on all the objects constituting the background. Therefore, there has been a problem that the calculation load becomes enormous when attempting to display a wide range of backgrounds.
JP-A-11-250232

  The present invention has been made in view of the above problems, and an object thereof is to provide a program, an information storage medium, and an image generation system that enable generation of a background image with a small processing load. There is.

  The present invention is an image generation system that generates an image, and controls a far-view image storage unit that stores a plurality of distant view images including distant view images that should be seen from a virtual camera at each position in an object space, and a virtual camera. A distant view image specified by the position of the virtual camera among the plurality of distant view images stored in the virtual camera control unit and the distant view image storage unit is arranged at a position away from the virtual camera by a given distance. The present invention relates to an image generation system including an image generation unit that maps to a distant view map object constituted by a primitive surface and generates an image that can be viewed from a virtual camera in the object space. The present invention also relates to a program that causes a computer to function as each of the above-described units, or a computer-readable information storage medium that stores the program.

  According to the present invention, a distant view image that should be visible from the virtual camera at each position in the object space is stored in the distant view image storage unit. Then, a distant view image specified by the position of the virtual camera among the distant view images stored in the distant view image storage unit is mapped to the distant view map object. Therefore, an image including a real distant view image can be generated without performing a distant view object drawing process in real time, and a background image can be generated with a small processing load.

  In the image generation system, the program, and the information storage medium according to the present invention, the image generation unit performs a drawing process of a foreground object that is arranged and set closer to the virtual camera than the distant object drawn in the distant image. May be.

  In this way, the foreground object can be drawn in real time, and the quality of the generated image can be improved.

  In the image generation system, the program, and the information storage medium according to the present invention, the distant view image storage unit draws an object that is farther from the virtual camera than the position of the primitive plane of the distant view map object as a distant view object. A distant view image may be stored, and the image generation unit may draw an object closer to the virtual camera than the position of the primitive surface of the distant view map object as a foreground object.

  In this way, a natural and realistic image can be generated even when a foreground object approaches in the immediate vicinity of the virtual camera.

  In the image generation system, the program, and the information storage medium according to the present invention, the image generation unit renders an object that is far from the position of the primitive plane of the distant view map object by a given distance range as a foreground object. May be.

  In this way, it is possible to seamlessly switch from the image drawn on the distant view map object to the image generated by drawing the foreground object, thereby preventing an unnatural image from being generated.

  In the image generation system, program, and information storage medium according to the present invention, the distant view image storage unit stores a Z value obtained at the time of generating each distant view image that should be seen from the virtual camera at each position in the object space. The image generation unit may perform hidden surface removal processing using the Z value of the distant view image.

  In this way, it is possible to display an image having a correct context even for a distant view image.

  In addition, the image generation system, the program, and the information storage medium according to the present invention may include a conversion processing unit that performs the conversion processing of the Z value according to the positional relationship between the visual line direction of the virtual camera and the distant view map object ( It may function as the conversion means).

  In this way, it is possible to convert the Z value of the distant view image into a correct Z value, and it is possible to realize hidden surface removal processing in which the context is correctly determined.

  In the image generation system, program, and information storage medium according to the present invention, the distant view map object is a distant view cube map object, and the distant view image storage unit stores a distant view image mapped to the distant view cube map object. And the image generation unit may map the distant view image stored in the distant view image storage unit to the distant view cube map object.

  In this way, it is possible to generate an image including a distant view image drawn on the distant view map object even when the line-of-sight direction of the virtual camera is front-rear, left-right, or the like.

  In the image generation system, the program, and the information storage medium according to the present invention, the image generation unit performs environment mapping on the moving object moving in the object space as an environment mapping image of the distant view map object. Also good.

  In this way, environment mapping can be realized by effectively utilizing the distant view image generated for distant view display.

  In the image generation system, the program, and the information storage medium according to the present invention, the distant view image storage unit stores the plurality of distant view images as compressed images, and the image generation unit obtains the decompressed images by decompressing the compressed images. The obtained distant view image may be mapped to the distant view map object.

  In this way, it is possible to save the used storage capacity necessary for storing the distant view image.

  In the image generation system, program, and information storage medium according to the present invention, the distant view image storage unit stores a plurality of distant view images as compressed movie textures, and the image generation unit expands the compressed movie textures. The obtained distant view image may be mapped to the distant view map object.

  In this way, it is possible to compress and expand a distant view image by effectively utilizing the movie texture playback function.

  In the image generation system, the program, and the information storage medium according to the present invention, the far-field image storage unit has a frame number closer to a far-field image whose positions in the object space when the image is generated by the virtual camera are closer to each other. You may memorize | store the compressed image compressed so that it might become.

  In this way, the distant view images of similar images are compressed and stored so that their frame numbers are close to each other, so that the compression efficiency can be improved and the used storage capacity of the memory can be saved.

  In the image generation system, the program, and the information storage medium according to the present invention, the image generation unit generates a distant view image corresponding to the position of the virtual camera from a plurality of distant view images obtained by expanding the compressed image. The distant view image specified by the frame number may be mapped to the distant view map object.

  In this way, even when the distant view image is compressed, the distant view image corresponding to the position of the virtual camera can be identified by simple processing and mapped to the distant view map object.

  In the image generation system, the program, and the information storage medium according to the present invention, only the compressed image of the distant view image corresponding to a given range around the virtual camera among the plurality of distant view images is decompressed, and the image generation unit May map a distant view image corresponding to the position of the virtual camera from the distant view image corresponding to the given range obtained by the expansion to the distant view map object.

  In this way, since it is not necessary to decompress distant view images corresponding to all positions in the object space, the processing load of the decompression process can be reduced.

  In the image generation system, the program, and the information storage medium according to the present invention, when generating a plurality of images in which each image is displayed on each of the plurality of screens, The first image and the second image for the second screen that can be seen from the second virtual camera may be generated by sharing the distant view image stored in the distant view image storage unit.

  In this way, it is possible to realize a multi-screen display by processing with a light load while suppressing an increase in the used storage capacity of the memory.

  In the image generation system, the program, and the information storage medium according to the present invention, the image generation unit includes first to Nth (N is a distant view image corresponding to the position of the virtual camera from the plurality of distant view images. The first to Nth distant view images associated with the position of an integer of 2 or more are read, and an image obtained by combining the read first to Nth distant view images is mapped to the distant view map object. May be.

  In this way, it is possible to generate and display a high quality distant view image while suppressing an increase in the amount of data.

  Hereinafter, this embodiment will be described. In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration requirements of the present invention.

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

  The operation unit 160 is for a player to input operation data, and the function can be realized by a lever, button, steering, accelerator, brake, touch panel display, or the like. The storage unit 170 serves as a work area for the processing unit 100, the communication unit 196, and the like, and its function can be realized by a RAM (VRAM) or the like.

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

  A program (data) for causing a computer to function as each unit of the present embodiment is distributed from the information storage medium of the host device (server) to the information storage medium 180 (or storage unit 170) via the network and communication unit 196. May be. Use of an information storage medium by such a host device (server) can also be included in the scope of the present invention.

  The processing unit 100 (processor) performs processing such as game processing, image generation processing, or sound generation processing based on operation data and programs from the operation unit 160. The processing unit 100 performs various processes using the storage unit 170 (main storage unit 172) as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs.

  The processing unit 100 includes a game calculation unit 108, an object space setting unit 110, a moving body calculation unit 112, a virtual camera control unit 114, an image generation unit 120, and a sound generation unit 130. Note that some of these may be omitted.

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

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

  The moving object calculation unit (movement / motion processing unit) 112 performs an operation for moving the moving object. Also, calculations for operating the moving body are performed. That is, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), etc., a moving body (object, model object) is moved in the object space, Performs processing to move the moving body (motion, animation). Specifically, a simulation process for sequentially obtaining movement information (position, rotation angle, speed, or acceleration) and motion information (part object position or rotation angle) of a moving body for each frame (1/60 second). I do. A frame is a unit of time for performing a moving / movement process (simulation process) and an image generation process of a moving object.

  The virtual camera control unit 114 performs a virtual camera (viewpoint) control process for generating an image viewed from a given (arbitrary) viewpoint in the object space. Specifically, processing for controlling the position (X, Y, Z) or rotation angle (rotation angle about the X, Y, Z axis) of the virtual camera (processing for controlling the viewpoint position, the line-of-sight direction or the angle of view) I do.

  For example, when shooting a moving body such as a car or character from behind using a virtual camera, the position or rotation angle of the virtual camera (the direction of the virtual camera) so that the virtual camera follows changes in the position or rotation of the moving body. To control. In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the moving object obtained by the moving object computing unit 112. Alternatively, the virtual camera may be controlled to rotate at a predetermined rotation angle or to move along a predetermined movement path. In this case, the virtual camera is controlled based on the virtual camera data for specifying the position (movement path) or rotation angle of the virtual camera.

  Note that the moving object of this embodiment may be an object displayed on the screen or a virtual object that is not displayed on the screen. For example, in the case of the first person viewpoint, the position of the virtual camera can be regarded as the moving body position.

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

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

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

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

  α blending (α synthesis) is processing performed based on an α value (A value), and includes normal α blending, addition α blending, subtraction α blending, and the like. For example, in the case of normal α blending, the following processing is performed.

R _Q = (1−α) × R ₁ + α × R ₂
G _Q = (1−α) × G ₁ + α × G ₂
B _Q = (1−α) × B ₁ + α × B ₂
On the other hand, in the case of addition α blending, the following processing is performed.

R _Q = R ₁ + α × R ₂
G _Q = G ₁ + α × G ₂
B _Q = B ₁ + α × B ₂
In the case of subtractive α blending, the following processing is performed.

R _Q = R ₁ −α × R ₂
G _Q = G ₁ −α × G ₂
B _Q = B ₁ −α × B ₂
Here, R ₁ , G ₁ , B ₁ are RGB components of an image (original image) already drawn in the drawing buffer 174 (frame buffer), and R ₂ , G ₂ , B ₂ are drawing buffers 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 translucency (equivalent to transparency and opacity) information, mask information, or bump information.

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

  In this embodiment, the distant view image storage unit 173 stores a plurality of distant view images (background images). Specifically, a plurality of distant view images (distant view textures) including each distant view image that should be seen from the virtual camera at each position in the object space are stored. For example, each distant view image stores a plurality of distant view images prepared corresponding to each position (grid point, reference point, position acquisition polygon, etc.). The image generation unit 120 then identifies a distant view image (distant view image associated with the position of the virtual camera) specified by the position of the virtual camera (moving body) among the plurality of distant view images stored in the distant view image storage unit 173. Are mapped to a distant view map object.

  Here, the distant view map object is an object composed of one or a plurality of primitive surfaces (polygons) arranged at a position away from the virtual camera by a given distance. As this distant view map object, for example, a distant view cube map object used for environment mapping can be used. In this case, the distant view image storage unit 173 stores the distant view image mapped to the distant view cube map object, and the image generation unit 120 converts the distant view image stored in the distant view image storage unit 173 into the distant view cube map object. To map. For example, a distant view image corresponding to a developed view of a cube is mapped to a polygon constituting a distant view cube map object.

  The image generation unit 120 performs a foreground object drawing process. Here, the foreground object is an object that is arranged closer to the virtual camera than the distant object drawn in the distant image. That is, the distant view image storage unit 173 is an object that is farther from the virtual camera than the position of the primitive plane (polygon) of the distant view map object (an object that is assumed to be more than a given threshold distance from the virtual camera). ) Stores a distant view image drawn as a distant view object. That is, when generating a distant view image at the time of game production or the like, an object far from the position of the primitive plane (polygon) of the distant view map object as viewed from the virtual camera is drawn in the distant view image as a distant view. On the other hand, the image generation unit 120 draws an object closer to the virtual camera than the position of the primitive surface of the distant view map object (an object closer to a given threshold distance from the virtual camera) as a foreground object. . Note that the image generation unit 120 draws an object that is far away from the primitive plane position of the distant view map object by a given distance range and is originally a distant view object as a foreground object.

  Further, the distant view image storage unit 173 stores the Z value obtained in the process of generating each distant view image that should be seen from the virtual camera at each position in the object space. For example, the Z value (Z plane) is stored together with the color (color plane) of the distant view image. That is, the Z value obtained by hidden surface removal by the Z buffer method is stored.

  Then, the image generation unit 120 performs hidden surface removal processing using the Z value of the distant view image. That is, when drawing an object such as a moving object, the hidden surface removal process by the Z buffer method is performed in consideration of the Z value of the distant view image. In this case, the conversion processing unit 122 included in the image generation unit 120 performs Z value conversion processing in accordance with the positional relationship between the viewing direction of the virtual camera and the distant view map object. Specifically, based on the angle between the direction of the primitive surface constituting the distant view map object and the line-of-sight direction, and the X coordinate, Y coordinate, etc. of the point (pixel) to be converted, the Z value of that point Convert.

  The distant view image storage unit 173 stores a plurality of distant view images as compressed images. For example, a plurality of distant view images are stored as compressed movie textures. More specifically, a compressed image that is compressed so that the distant view images whose positions in the object space at the time of image generation by the virtual camera are closer to each other has a closer frame number is stored.

  A decompression unit (decompression unit, decoding unit) 124 included in the image generation unit 120 performs decompression processing of the compressed image. Specifically, the distant view image (movie texture) stored in the distant view image storage unit 173 as a compressed image such as MPEG or JPEG is expanded. For example, a series of I pictures compressed by MPEG is expanded.

  Data compression of a distant view image can be realized as follows. That is, first, data is divided into a plurality of macroblocks. Then, DCT (Discrete Cosine Transform, Orthogonal Transform) is performed on each divided block. Thereby, the data is decomposed in frequency (spatial frequency). Next, each DCT coefficient (orthogonal transform coefficient in a broad sense) obtained by DCT is quantized. Then, Huffman coding (entropy coding, variable length coding) is performed, whereby compressed data is obtained. On the other hand, data decompression of a compressed image can be realized as follows. That is, first, the compressed data is read from the distant view image storage unit 173. The decompression unit 124 performs Huffman decoding (entropy decoding, variable length decoding) on the read compressed data. Next, the decompression unit 124 performs inverse quantization on the data after Huffman decoding. Then, inverse DCT is performed, whereby decompressed data is obtained.

  The image generation unit 120 maps the distant view image obtained by decompressing (decoding) the compressed image to the distant view map object. For example, a distant view image obtained by expanding a compressed movie texture is mapped to a distant view map object. Specifically, a distant view image corresponding to the position of the virtual camera is specified by a frame number from among a plurality of distant view images obtained by decompressing the compressed image. For example, the position of the virtual camera is associated with the frame number, the frame number is specified from the position of the virtual camera, and the distant view image specified by the frame number is mapped to the distant view map object.

  The image generation unit 120 can generate a plurality of images in which each image is displayed on each of a plurality of screens. That is, images with different virtual camera positions (viewpoint positions) and line-of-sight directions are generated and displayed on each screen corresponding to each player. For example, a first image for the first screen (first view image) that can be seen from the first virtual camera, and a second image for the second screen (second view image that can be seen from the second virtual camera) ) And displayed on the first and second screens. In this case, the image generation unit 120 generates the first image for the first screen and the second image for the second screen by sharing the distant view image stored in the distant view image storage unit 173. . For example, the first image to be displayed on the first screen is generated using a distant view image associated with the Kth position among a plurality of distant view images stored in the distant view image storage unit 173. On the other hand, the second image displayed on the second screen is generated using a distant view image associated with the Lth position among the plurality of distant view images stored in the distant view image storage unit 173.

  In addition, the image generation unit 120 reads out the first to Nth distant view images associated with the first to Nth positions as the distant view images corresponding to the position of the virtual camera from the plurality of distant view images. Specifically, the first to Nth distant view images associated with the first to first positions near the virtual camera are read from the distant view image storage unit 173. An image obtained by combining the read first to Nth distant view images is mapped to the distant view map object. Specifically, the α value is obtained based on the positional relationship (distance etc.) between the position of the virtual camera and the first to Nth positions, and the first to Nth distant view images are obtained based on the obtained α value. Is alpha-combined and mapped to a distant view map object.

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

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

2. 2. Method of this embodiment 2.1 Mapping of a distant view image to a distant view map object In this embodiment, as shown in FIG. 2, a virtual camera (moving) is provided at each position P11, P12, P13, P14, P15. Distant view images (background images) IM11, IM12, IM13, IM14, IM15... To be seen from the body) are stored in the distant view image storage unit 173. Specifically, at the time of game production (CG production), a virtual camera is arranged and set at each position P11, P12, P13. And the image which should be seen when the surroundings are looked around by the virtual camera arrange | positioned at each position P11, P12, P13 ... is produced | generated. The image generated in this way is stored in the distant view image storage unit 173 as a distant view image. In this case, the distant view image is generated by arranging distant view objects in the object space among the objects constituting the background. Further, this far-view image generation process is performed at the time of game production and does not require real-time performance, and therefore a distant view image is generated using a detailed model having an extremely large number of polygons. 2, the distant view images IM11, IM12, IM13... Are stored in the distant view image storage unit 173 in association with the positions P11, P12, P13. Note that the positions P11, P12, P13,... May be associated with frame numbers, and the frame numbers and the distant view images IM11, IM12, IM13,. .

  FIG. 3 shows an example of a distant view image of the present embodiment. A1 in FIG. 3 is an image that can be seen when the virtual camera is turned to the left with respect to the traveling direction. Similarly, A2, A3, A4, A5, and A6 are images (a two-dimensional image and a pseudo three-dimensional image) that can be seen when the virtual camera is pointed forward, right, back, up, and down. In these images, a distant view object such as a spectator seat, a wall, a sky, a cloud and the like located far from the virtual camera is drawn. A road (course) image is also drawn. The distant view image storage unit 173 stores, as a distant view image, for example, a set of images A1 to A6 in FIG. In addition, you may make it memorize | store each image of A1-A6 of FIG. 3 as a distant view image separately.

  In this embodiment, the distant view image of FIG. 3 is mapped to a distant view map object (distant view cube map object) MOB as shown in FIG. 4, for example, and an image that can be seen from the virtual camera VC in the object space (game space) is generated. Specifically, the images A1, A2, A3, A4, A5, and A6 in FIG. 3 are mapped to the primitive planes (polygons) PS1, PS2, PS3, PS4, PS5, and PS6 constituting the distant view map object MOB, respectively. . That is, the images of A1 to A6 are mapped to the inner surfaces that are visible from the virtual camera VC among the outer and inner surfaces (front and back surfaces) of the primitive surfaces PS1 to PS6. Then, from the virtual camera VC arranged inside the distant view map object MOB, by viewing the inner surface of these distant view map objects MOB, an image similar to that at the time of game (CG) production is displayed on the virtual camera. As a result, a distant view (background) image constituting the game image is displayed on the display unit 190.

  2, 3, and 4, images in six directions of up, down, front, back, left, and right are prepared at each position in the object space and mapped inside the distant view map object MOB (cube map object). Therefore, when the virtual camera VC faces in any direction such as up / down / front / back / left / right, a distant view image (background image) corresponding to the direction is displayed on the display unit 190.

  According to such a method of the present embodiment, it is not necessary to draw a distant view object constituting a distant view image in real time. Therefore, the processing load can be reduced. Since the distant view is prepared in advance as a two-dimensional image (pseudo three-dimensional image), the processing load does not change so much even if a distant view of a wide distance range is displayed. Therefore, it is possible to display a distant view over a wide distance range with a small processing load. Furthermore, a distant view image can be generated at the time of game production without being generated in real time. Therefore, it is possible to prepare a high-definition distant view image as compared with the case of generating by real-time processing, and it is possible to generate a realistic image with a small processing load.

  Note that objects of various shapes can be adopted as the distant view map object MOB. For example, an object in which a part of the primitive surfaces PS1 to PS6 in FIG. 4 is omitted may be used. For example, in a game (such as a train game) in which the virtual camera VC does not face the rear side, the upper side, or the lower side, a distant view map object MOB that does not include the primitive planes PS4, PS5, and PS6 can be employed. The distant view map object of the present embodiment is not limited to the distant view map object of the cube as shown in FIG. For example, a rectangular parallelepiped map object is used in FIG. 5A, and a cylindrical distant map object is used in FIG. 5B. The distant view map object may be, for example, an object composed of primitive surfaces positioned at least on the front, left, and right sides of the virtual camera.

  In FIG. 2, a plurality of distant view images are associated with the positions of lattice points in the object space, but the present embodiment is not limited to this. For example, in FIG. 6A, reference points G1, G2, G3... Are set along the course of the object space. That is, in FIG. 6A, in order to grasp the current position and order of the moving body on the course, reference points G1, G2, G3... Are set along the center line (reference line) of the course. A road coordinate system using a line connecting these reference points G1, G2, G3... As a coordinate axis is used. The current position and order of the moving object are acquired by searching for the reference point closest to the moving object (virtual camera) among the reference points G1, G2, G3.

  The distant view image of the present embodiment may be stored in association with these reference points G1, G2, G3. For example, in a train game or the like in which an image seen from a train running on the rail is displayed, the position of the virtual camera does not shift to the left or right of the rail. Therefore, in such a train game or the like, a distant view image may be stored in association with the reference points G1, G2, G3,.

  Further, as shown in FIG. 6B, lattice points associated with a distant view image may be set only in the movable range of the virtual camera (moving body). In this way, the data amount of the distant view image can be reduced, and the used storage capacity of the memory can be saved. Also, a plurality of position acquisition (coordinate calculation) polygons are arranged in the movement field of the virtual camera (moving body), and a distant view image is associated with each subdivided polygon and stored. May be. In this case, attribute information such as movement condition information and an event generation flag can be set for each polygon, and the movement of the moving body can be controlled based on this attribute information, or a game event can be generated. .

2.2 Drawing foreground objects In this embodiment, drawing processing is performed for foreground objects that are arranged and set closer to the virtual camera than the distant objects (audience seats, walls, etc.) drawn in the distant view image of FIG. .

  Specifically, as shown in B1 and B2 of FIGS. 7A and 7B, an object OB2 that is farther from the virtual camera VC than the position of the primitive plane PS2 of the far view map object MOB is a far view object. It is drawn in a distant view image. For example, objects such as spectator seats and backgrounds in FIG. 3 are drawn as a distant view object in a distant view image and stored in the distant view image storage unit 173. FIG. 7A is a view when the distant view map object MOB, virtual camera VC, objects OB1, OB2, etc. are viewed from the horizontal direction (direction along the X axis), and FIG. 7B is the upward direction. It is a figure at the time of seeing from (direction along the Y-axis).

  In this embodiment, the image generation unit 120 draws an object OB1 that is closer to the virtual camera VC than the position of the primitive plane PS2 of the distant view map object MOB as a foreground object.

  That is, in the present embodiment, the primitive plane PS2 constituting the distant view map object MOB is arranged at a position away from the virtual camera VC by a given distance. Accordingly, the object OB2 farther than the primitive surface PS2 is not unnatural even if it is drawn on a distant view image as shown by B1 and B2 in FIGS. 7A and 7B. If the object OB1 on the near side is drawn on a distant view image, an unnatural image may be generated. For example, when the object OB1 comes close to the eyes of the virtual camera VC, the shape and image of the object OB1 are displayed large, and the details are conspicuous.

  Therefore, in FIGS. 7A and 7B, the object OB1 on the near side of the primitive surface PS2 is drawn as a foreground object in normal real-time processing. In this way, a natural and realistic image can be generated even when the object OB1 approaches the front of the virtual camera VC.

  In the present embodiment, as shown in FIG. 8A, an object OB3 that is a given distance range away from the position of the primitive plane PS2 of the distant view map object MOB may be drawn as a foreground object. For example, in FIG. 8A, an area EAR wider than the MOB is set around the distant view map object MOB. In principle, an object placed outside the distant view map object MOB is not drawn as a foreground object in real time, but an object OB3 located outside the distant view map object MOB and inside the region EAR is Draw in real time as a foreground object. In this case, as indicated by C1 in FIG. 8A, this object OB3 is also drawn in the distant view image as a distant view object.

  In this way, as shown in FIG. 8B, when the position of the virtual camera VC (moving object) changes and the object OB3 enters the distant view map object MOB, the image of the object OB3 is distant. The image is switched from the image to the foreground image without any unnaturalness. For example, in FIG. 8A, if the object OB3 is not drawn as a foreground object, when the object OB3 comes to the position of the primitive plane PS2, it is suddenly displayed as a real-time drawing object, and an unnatural image is displayed. May be generated.

  In this regard, in FIG. 8A, the object OB3 is drawn as a foreground object from the time when it is located in the area EAR. Therefore, even when the object OB3 comes to the position of the primitive surface PS2, the image drawn on the distant view map object MOB is seamlessly switched from the image drawn by real-time drawing to an unnatural image. Can be effectively prevented.

2.3 Hidden surface removal using Z values In this embodiment, as shown in FIG. 9A, not only R, G, and B colors (color planes) but also Z values (depths) for distant view images. Synonymous with value). That is, the Z value (Z plane) obtained at the time of generating each distant view image that should be visible from the virtual camera at each position in the object space (when creating a game) is set as the distant view image. Then, when drawing an object (foreground object, moving object, etc.), the hidden surface removal process is performed using not only the Z value of the object but also the Z value of the distant view image.

  For example, in FIG. 9B, an object OB4 (for example, a building) is depicted in a distant view image as a distant view object. In this case, in the drawing area of the object OB4 in the distant view image, not only the color of the object OB4 but also the Z value (Z value obtained by the Z buffer method) obtained when the image of the object OB4 is generated. Set (stored). Then, when drawing another object OB5 (for example, an airship) in real time, the hidden surface removal process is performed in consideration of the Z value of the distant view image. In this way, as shown in FIG. 9B, the portion of the object OB5 located behind the object OB4 is hidden and is not displayed. Therefore, it becomes possible to display an image having a correct context, and the realism and quality of the generated image can be improved. The Z value of the distant view image may be stored in the α plane of the distant view image, for example, and the Z value of the α plane may be written in the Z buffer before the object OB5 is drawn.

  In the present embodiment, depth Z value conversion processing is performed in accordance with the viewing direction of the virtual camera. In other words, the Z value of the distant view image is subjected to conversion processing according to the positional relationship between the viewing direction of the virtual camera and the distant view map object. In the following, in order to simplify the description, only one-axis rotation on the XZ plane is considered.

  For example, in FIG. 10, the viewpoint position of the virtual camera VC is VP, and the line-of-sight directions are EV and EV ′. Further, the X and Z coordinates of the point P when the visual line direction of the virtual camera VC is EV are XP and ZP. This point P is a point (pixel) of a distant view object constituting the distant view image. In the Z plane of the distant view image, a Z value is set when the virtual camera VC faces the primitive plane PS2 and the line-of-sight direction is the EV direction. Therefore, when the line-of-sight direction of the virtual camera VC changes from EV to EV ′, Z value conversion processing is required.

  For example, in FIG. 10, the angle formed by the line-of-sight directions EV and EV ′ is θ. Then, the Z value ZP ′ of the converted point P can be expressed as the following equation.

ZP ′ = ZP × COSθ + XP × SINθ
That is, in the above equation, the Z value conversion process is performed according to the positional relationship between the visual line direction EV of the virtual camera VC and the distant view map object MOB. Specifically, the angle θ formed by the direction EV corresponding to the orientation of the primitive plane PS2 constituting the distant view map object MOB and the line-of-sight direction EV ′ of the current virtual camera VC, and X of the target point P (pixel) Based on the coordinates, Y coordinates, etc., the Z value of the point P is converted from ZP to ZP ′. Then, based on the Z value ZP ′ obtained by the conversion, a hidden surface removal process is performed. In this way, the Z value set for the distant view image can be converted to the correct Z value, and the hidden surface removal process in which the context is correctly determined can be realized.

2.4 Environment Mapping In this embodiment, as shown in FIG. 11, the environment mapping is performed on the distant view image of the distant map object MOB as the environment mapping image with respect to the moving object MB moving in the object space. That is, in FIG. 11, the virtual camera VC moves following the moving body MB, and an image of the moving body MB is displayed in an image that can be seen from the virtual camera VC. At this time, a distant view image when the surroundings are looked around by the virtual camera VC is mapped inside the distant view map object MOB.

  Therefore, in the present embodiment, this distant view image is mapped to the mobile object MB as an environment mapping image. In this way, a distant view image when the surroundings are looked around by the virtual camera VC is mapped to the moving body MB, and environment mapping can be realized. Therefore, since the environment mapping can be realized by effectively using the distant view image generated for distant view display, a realistic image can be generated without increasing the processing load so much.

  The environment mapping in FIG. 11 can be realized by the following method, for example. For example, in FIG. 11, a normal vector N is set for each point (vertex, pixel, surface) of the moving body MB. In this case, the normal vector N is coordinate-converted to, for example, a viewpoint coordinate system using a coordinate conversion matrix. Then, based on, for example, X and Y coordinates of the normal vector N after coordinate conversion, texture coordinates TX and TY for environment mapping are obtained. Then, based on the obtained texture coordinates TX and TY, a distant view image (distant view texture) of the distant map object MOB is sampled and mapped to the moving object MB. In this way, a realistic distant view image corresponding to the direction in which the virtual camera VC faces is environment-mapped on the moving body MB.

  Note that a distant view image sampled by the normal vector N of the moving object MB may be mapped to the moving object MB as it is without depending on the direction in which the virtual camera VC faces. Although FIG. 11 shows an example of cube environment mapping, the environment mapping of the present embodiment is not limited to such cube environment mapping, and may be tetrahedral environment mapping or the like.

2.5 Compression of Distant View Image In this embodiment, a distant view image corresponding to each position in the object space is prepared. Therefore, there is a problem that the use storage capacity necessary for storing the distant view image becomes large.

  Therefore, in this embodiment, a plurality of distant view images are stored as compressed images, and distant view images obtained by expanding the compressed images are mapped to distant view map objects.

  For example, this type of image generation system often has a movie texture playback function for playback of a CG movie on an opening screen or an ending screen. In this embodiment, the movie texture playback function is effectively used to compress and decompress a distant view image. Specifically, as shown in FIG. 12A, a plurality of distant view images are stored as compressed movie textures CTEX11, CTEX12, CTEX13, CTEX14. Then, the distant view images IM11, IM12, IM13, IM14,... Obtained by expanding these compressed movie textures CTEX11, CTEX12, CTEX13, CTEX14,.

  For example, in FIG. 12B, compressed movie textures CTEX11, CTEX12, CTEX13,... Are associated with each position P11, P12, P13,. Accordingly, the distant view images IM11, IM12, IM13,... Obtained by expanding these compressed movie textures CTEX11, CTEX12, CTEX13,... Are also associated with the positions P11, P12, P13,. become. Therefore, it is possible to compress and expand distant view images by effectively using the movie texture playback function of the image generation system, and it is possible to efficiently compress and expand distant view images without introducing a new compression / decompression algorithm. It becomes like this.

  Further, in the present embodiment, a compressed image is stored which is compressed so that the distant view images whose positions in the object space at the time of image generation by the virtual camera are closer to each other have the closer frame numbers. For example, as shown in FIG. 2, the positions P11 and P12 are close positions, and IM11 and IM12 are distant view images whose positions in the object space at the time of image generation by the virtual camera are close to each other. These distant view images IM11 and IM12 are stored as compressed images (compressed movie textures) CTEX11 and CTEX12 that are compressed so that the frame numbers are close to 1 and 2, for example. Similarly, positions P13 and P14 are close to each other, and IM13 and IM14 are distant view images that are close to each other in the object space when an image is generated by the virtual camera. These images IM13 and IM14 are stored as compressed images (compressed movie textures) CTEX13 and CTEX14 that are compressed so that their frame numbers are close to 3 and 4, for example.

  For example, the distant view image IM11 seen from the virtual camera at the position P11 in the object space and the distant view image IM12 seen at the position P12 are similar because the positions P11 and P12 are close to each other. Therefore, as shown in FIG. 12C, if the frame numbers of these distant view images IM11 and IM12 are compressed so that they are close to each other, the distant view images IM11 and IM12 can be compressed as if they were moving images. Efficiency can be improved. That is, the distant view images IM11 and IM12 are similar images, and their difference components (motion vectors) are small, so that the compression efficiency is increased and the data amount of the compressed image can be reduced. As a result, the used storage capacity of the memory can be saved, and a high-quality image can be generated with fewer resources.

  In the present embodiment, a distant view image corresponding to the position of the virtual camera is specified by a frame number from a plurality of distant view images obtained by decompressing the compressed image, and the specified distant view image is defined as the distant view map object. Is mapped. For example, in FIG. 12C, when the position of the virtual camera is P11, the frame number of the distant view image IM11 corresponding to the position P11 of the virtual camera is selected from the plural distant view images IM11, IM12, IM13. = 1, and the specified distant view image IM11 is mapped to the distant view map object. Similarly, when the position of the virtual camera is P12, the distant view image IM12 corresponding to the position P12 of the virtual camera is specified by the frame number = 2 from the plurality of distant view images IM11, IM12, IM13. The identified distant view image IM12 is mapped to the distant view map object. In this way, the distant view image can be specified and mapped to the distant view map object simply by associating the frame number with each position in the object space.

  FIG. 13 shows an example of the data structure of the compressed movie information. The compressed movie information includes a header block (compressed movie texture control information), a frame data address block (information specifying the storage location of the compressed texture), and a frame data block (compressed texture data, MPEG I picture data). Have

  Here, the header block is the data size of the compressed movie information, the frame width (the number of texels in the texture width direction), the frame height (the number of texels in the texture height direction), the number of frames of the movie texture, etc. Including data.

  The frame data address block includes addresses (data for designating the storage location; head address) of each compressed movie texture CTEX11 to CTEXMN (frames 1 to M × N) in the frame data block and each of the CTEX11 to This includes the data size of CTEXMN and the end code address in the frame data block.

  The frame data block includes data (image data) of CTEX11 to CTEXMN (frames 1 to M × N), a delimiter code of each frame, and an end code of the frame data block.

  In the present embodiment, compressed movie information having a data structure as shown in FIG. 13 is created from data of compressed movie textures CTEX11 to CTEXMN (frames 1 to M × N). In this embodiment, the distant view image specified by the frame number is mapped to the distant view map object using the compressed movie information having such a data structure.

  For example, when mapping a distant view image of frame number 1, the address of the compressed movie texture CTEX11 is acquired from the frame data address block. Then, the data of the compressed movie texture CTEX11 at the address is decompressed by the decompression unit 124 to obtain the distant view image IM11. Then, the obtained distant view image IM11 is mapped to the distant view map object. Similarly, when mapping the distant view image of frame number 2, the address of the compressed movie texture CTEX12 is acquired from the frame data address block. Then, the data of the compressed movie texture CTEX12 at the address is decompressed by the decompression unit 124 to obtain the distant view image IM12. Then, the obtained distant view image IM12 is mapped to the distant view map object. By doing so, it is possible to map a distant view image using a compressed movie texture.

  In order to reduce the processing load and improve the use efficiency of the memory, it is desirable to adopt the method as shown in FIG. That is, in FIG. 14, only the compressed image of the distant view image corresponding to the given range AR1 (grid point) around the virtual camera VC is decompressed among the plural distant view images. That is, not only all the positions in the object space but only the compressed image (compressed movie texture) of the distant view image associated with the position in the range AR1 is expanded and expanded in the main storage unit 172 of the storage unit 170, for example. This range AR1 is set around the virtual camera VC, and moves with the movement of the virtual camera VC (moving body).

  Then, the image generation unit 120 maps a distant view image corresponding to the position of the virtual camera VC from the distant view image corresponding to the range AR1 obtained by the expansion to the distant view map object. That is, the far-field image corresponding to the position of the virtual camera VC is read from the far-field images corresponding to the range AR1 developed in the main storage unit 172, and the read far-field image is mapped to the far-field map object.

  According to the method of FIG. 14, it is not necessary to expand a distant view image corresponding to all positions in the object space, so that the processing load of the expansion unit 124 can be reduced. Further, since only the compressed image of the distant view image corresponding to the range AR1 is developed in the main storage unit 172, the use storage capacity of the main storage unit 172 can be saved, and the use efficiency of the memory can be improved.

  As shown in FIG. 14, the range AR1 can be set so as to cover a course CS on which a moving body (such as a car) followed by the virtual camera VC moves. The size of the range AR1 can be set according to movement information such as the speed of the moving object.

2.6 Multiple Screen Display The image generation unit 120 of the present embodiment can generate a plurality of images in which each image is displayed on each of a plurality of screens. For example, in FIG. 15, a first image IM1 for the first screen DS1 and a second image IM2 for the second screen DS2 are generated and displayed on the screens DS1 and DS2. Here, the image IM1 is a view field image that can be seen from the first virtual camera for the screen DS1. The image IM2 is a view field image that can be seen from the second virtual camera for the screen DS2. These first and second virtual cameras have different viewpoint positions and line-of-sight directions.

  That is, the first moving body MB1 operated by the first player is displayed in the image IM1, and the second moving body MB2 operated by the second player is displayed in the image IM2. The image IM1 is an image displayed by the first virtual camera corresponding to the viewpoint of the first player, and the image IM2 is an image displayed by the second virtual camera corresponding to the viewpoint of the second player. . By dividing and displaying the screen as shown in FIG. 15, it is possible to display a game image in which a plurality of players can play and enjoy the game.

  In FIG. 15, the screens DS1 and DS2 are screens obtained by dividing the screen of one display unit, but the screen of the first display unit is the screen DS1, and the screen of the second display unit is the screen DS2. Also good.

  In the present embodiment, images IM1 and IM2 for the screens DS1 and DS2 as shown in FIG. 15 are generated by sharing the distant view image stored in the distant view image storage unit 173. Specifically, when the position of the virtual camera (mobile body MB1) for the screen DS1 is P11, the image IM1 for the screen DS1 is generated using the distant view image IM11 associated with the position P11. . When the position of the virtual camera (moving body MB2) for the screen DS2 is P53, the image IM2 for the screen DS2 is generated using the distant view image IM53 associated with the position P53.

  For example, when the two-screen display as shown in FIG. 15 is performed without employing the method of the present embodiment, the drawing process of the object for the screen DS1 and the drawing process of the object for the screen DS2 are necessary. The processing load is about twice that of a single screen display. For this reason, real-time image generation becomes difficult. In particular, when the number of screen divisions further increases, the problem of an increase in processing load becomes serious.

  In this regard, according to the present embodiment, the distant view object is drawn in advance in the distant view image. Therefore, even when two-screen display is performed as shown in FIG. 15, the processing load does not increase much compared to the case of single-screen display.

  In FIG. 15, the image IM1 for the screen DS1 and the image IM2 for the screen DS2 are generated by sharing the distant view image storage unit 173. That is, the distant view image IM11 used for generating the image IM1 and the distant view image IM53 used for generating the image IM2 are distant view images stored in the same distant view image storage unit 173. Therefore, according to the method of FIG. 15, there is an advantage that the two-screen display as shown in FIG. 15 can be realized by processing with a light load while suppressing an increase in the used storage capacity of the memory.

2.7 Composition of Distant View Image In order to generate a more accurate distant view image, the density (grid point density) of the positions P11, P12, P13... In FIG. However, when the position density is increased in this way, a far-field image having a larger amount of data must be stored, and the use storage capacity of the memory increases.

  Therefore, in the present embodiment, a technique is adopted in which a distant view image obtained by combining a plurality of distant view images is mapped to a distant view map object.

  For example, in FIG. 16, positions P11 and P12 (first to Nth positions in a broad sense) as distant view images corresponding to the position of the virtual camera VC from among a plurality of distant view images stored in the distant view image storage unit 173. The distant view images IM11 and IM12 (first to Nth distant view images in a broad sense) associated with are read out. Then, an image obtained by combining the read distant view images IM11 and IM12 is mapped to the distant view map object.

  Specifically, in FIG. 16, a distance L1 between the position P11 and the virtual camera VC and a distance L2 between the position P12 and the virtual camera VC are obtained. Based on these distances L1 and L2, the α value at the time of synthesizing the distant view images IM11 and IM12 is obtained.

For example, the R, G, and B components of the distant view image IM11 are R ₁₁ , G ₁₁ , and B _11, and the R, G, and B components of the distant view image IM12 are R ₁₂ , G ₁₂ , and B ₁₂ . Further, R, G, and B components of the distant view image IMA obtained by the synthesis are represented by Ra, Ga, and Ba. Then, for example, the following equation holds.

Ra = (1-α) × R ₁₁ + α × R ₁₂
Ga = (1-α) × G ₁₁ + α × G ₁₂
Ba = (1−α) × B ₁₁ + α × B ₁₂
α = L1 / (L1 + L2)
As described above, according to the technique using the distant view image obtained by combining a plurality of distant view images, a more accurate distant view image can be generated without increasing the density of the positions P11, P12, P13. Therefore, it is possible to generate and display a high quality distant view image while suppressing an increase in the data amount.

  It should be noted that the distant view image composition method can be variously modified. For example, in the above equation for interpolation processing, distant view images at two positions are combined, but distant view images at three or more positions may be combined. Further, not only the colors such as R, G, and B but also the Z value of the distant view image may be obtained by the interpolation processing as in the above equation.

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

  First, the virtual camera position (viewpoint position) and line-of-sight direction are obtained (step S1). For example, the position and direction of the moving body are obtained based on operation data from the operation unit 160, a program, and the like, and the position and line-of-sight direction of the virtual camera following the moving body are obtained. Alternatively, the position and line-of-sight direction of the virtual camera are obtained based on the virtual camera control data (control program).

  Next, a target distant view image is specified based on the obtained position of the virtual camera (step S2). For example, in FIG. 12C, a frame number is specified by the position of the virtual camera, and a distant view image is specified by this frame number.

  Next, as described in FIG. 12A, the compressed distant view movie texture is expanded (step S3). Then, the texture of the distant view image obtained by the expansion is mapped to a distant view cube map object as shown in FIG. 4 (step S4).

  Next, the distant view cube map object is drawn in the drawing buffer according to the viewing direction of the virtual camera (step S5). At this time, as described in FIG. 10, the Z value is converted in accordance with the line-of-sight direction. Then, as described in FIGS. 7A and 7B, the foreground object is drawn in the drawing buffer (step S6). Next, a moving body such as a car is drawn in the drawing buffer (step S7). At this time, as described with reference to FIG. 11, the texture of the distant view cube map object is environment-mapped with respect to the moving object.

3. Hardware Configuration FIG. 18 shows an example of a hardware configuration capable of realizing this embodiment. The main processor 900 operates based on a program stored in a DVD 982 (information storage medium, which may be a CD), a program downloaded via the communication interface 990, a program stored in the ROM 950, or the like. Perform processing, sound processing, etc. The coprocessor 902 assists the processing of the main processor 900, and executes matrix operation (vector operation) at high speed. For example, when a matrix calculation process is required for a physical simulation for moving or moving an object, a program operating on the main processor 900 instructs (requests) the process to the coprocessor 902.

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

  The drawing processor 910 executes drawing (rendering) processing of an object composed of primitive surfaces such as polygons and curved surfaces. When drawing an object, the main processor 900 uses the DMA controller 970 to pass the drawing data to the drawing processor 910 and, if necessary, transfers the texture to the texture storage unit 924. Then, the drawing processor 910 draws the object in the frame buffer 922 while performing hidden surface removal using a Z buffer or the like based on the drawing data and texture. The drawing processor 910 also performs α blending (translucent processing), depth cueing, mip mapping, fog processing, bilinear filtering, trilinear filtering, anti-aliasing, shading processing, and the like. When a programmable shader such as a vertex shader or a pixel shader is installed, the vertex data is created / changed (updated) and the drawing color of a pixel (or fragment) is determined according to the shader program. When an image for one frame is written in the frame buffer 922, the image is displayed on the display 912.

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

  The ROM 950 stores system programs and the like. In the case of an arcade game system, the ROM 950 functions as an information storage medium, and various programs are stored in the ROM 950. A hard disk may be used instead of the ROM 950. The RAM 960 is a work area for various processors. The DMA controller 970 controls DMA transfer between the processor and the memory. The DVD drive 980 (may be a CD drive) accesses a DVD 982 (may be a CD) in which programs, image data, sound data, and the like are stored. The communication interface 990 performs data transfer with the outside via a network (communication line, high-speed serial bus).

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

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

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

  Further, the far-field image mapping method, the far-field image compression / decompression method, and the far-field image composition method are not limited to those described in this embodiment, and methods equivalent to these methods are also included in the scope of the present invention.

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

The example of a functional block diagram of the image generation system of this embodiment. Explanatory drawing of the method of this embodiment. An example of a distant view image. An example of a distant view map object. 5A and 5B show other examples of the distant view map object. 6A and 6B are explanatory diagrams of a method using a reference point and a position acquisition polygon. 7A and 7B are explanatory diagrams of a drawing method for a foreground object. 8A and 8B are explanatory diagrams of a drawing method for a foreground object. 9A and 9B are explanatory diagrams of a hidden surface removal method using the Z value of a distant view image. Explanatory drawing of the conversion method of Z value. Explanatory drawing of the environment mapping method using a distant view image. 12A, 12B, and 12C are explanatory diagrams of a method for compressing and expanding a distant view image. An example of the data structure of compressed movie information. Explanatory drawing of the method of decompress | decompressing only the compression image of the distant view image corresponding to a given range. Explanatory drawing of the method which produces | generates the 1st, 2nd image for 1st, 2nd screens by sharing a distant view image memory | storage. Explanatory drawing of the method of synthesize | combining several distant view images. The detailed example of the process of this embodiment. Hardware configuration example.

Explanation of symbols

100 processing unit, 108 game calculation unit, 110 object space setting unit,
112 moving body calculation unit, 114 virtual camera control unit, 120 image generation unit,
122 conversion processing unit, 124 expansion unit, 130 sound generation unit,
160 operation unit, 170 storage unit, 172 main storage unit,
173 Distant view image storage unit, 174 drawing buffer, 176 model data storage unit,
180 information storage medium, 190 display unit, 192 sound output unit,
194 Portable information storage device, 196 communication unit

Claims (22)

A program for image generation,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. As an image generation unit that maps to a distant view map object and generates an image that can be seen from a virtual camera in the object space,
Make the computer work,
The distant view map object is a distant view cube map object composed of a plurality of primitive surfaces,
The distant view image storage unit
Storing a distant view image to be mapped to the distant view cube map object;
The image generation unit
Mapping the distant view image stored in the distant view image storage unit to the distant view cube map object ;
The distant view image storage unit
As each far view image that should be seen from the virtual camera at each position in the object space, an object that is farther from the virtual camera than the position of the primitive plane of the far view map object is stored as a far view object.
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Program to do. In claim 1,
The distant view image storage unit
Each image that should be seen when the virtual camera is pointed up, down, left, right, back and forth at each position in the object space is stored as the distant view image,
The image generation unit
A program that maps each of the images that should be seen when the virtual camera is directed up, down, left, and right, back and forth, to each primitive surface of a plurality of primitive surfaces constituting the distant view cube map object. In claim 1 or 2,
The image generation unit
A program for performing drawing processing of a foreground object placed and set nearer to a virtual camera than a distant object drawn in the distant image. In claim 3,
Before Symbol image generation unit,
A program for drawing an object closer to the virtual camera than the position of the primitive plane of the distant view map object as a foreground object. In claim 4,
The image generation unit
A program that draws an object that is far from a position of a primitive plane of the distant view map object by a given distance range as a foreground object. A program for image generation,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. As an image generation unit that maps to a distant view map object and generates an image that can be seen from a virtual camera in the object space,
Make the computer work,
The distant view image storage unit
Storing the Z value generated by the hidden surface removal process of the Z buffer method in the process of generating each distant view image that should be seen from the virtual camera at each position in the object space where the distant object is placed;
The image generation unit
When drawing the object, not only the Z value of the object but also the Z value of the distant image is used to perform hidden surface removal processing ,
The distant view image storage unit
As each far view image that should be seen from the virtual camera at each position in the object space, an object that is farther from the virtual camera than the position of the primitive plane of the far view map object is stored as a far view object.
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Program to do. In claim 6,
As a conversion processing unit that performs the conversion processing of the Z value according to the positional relationship between the visual line direction of the virtual camera and the distant view map object,
A program characterized by causing a computer to function. In claim 6 or 7,
The distant view map object is a distant view cube map object,
The distant view image storage unit
Storing a distant view image to be mapped to the distant view cube map object;
The image generation unit
A program for mapping a distant view image stored in the distant view image storage unit to the distant view cube map object. In any one of Claims 1 thru | or 8.
The image generation unit
A program for performing environment mapping of a distant view image of the distant view map object as an environment mapping image on a moving object moving in an object space. In any one of Claims 1 thru | or 9,
The distant view image storage unit
Storing the plurality of distant view images as compressed images;
The image generation unit
A program for mapping a distant view image obtained by decompressing the compressed image to the distant view map object. In claim 10,
The distant view image storage unit
Store multiple distant view images as compressed movie textures,
The image generation unit
A program for mapping a distant view image obtained by decompressing the compressed movie texture to the distant view map object. In claim 10 or 11,
The distant view image storage unit
A program that stores a compressed image that is compressed so that a distant view image whose position in the object space is closer to each other in the object space when the image is generated by the virtual camera is closer to the frame number. In claim 12,
The image generation unit
A distant view image corresponding to the position of a virtual camera is specified by the frame number from a plurality of distant view images obtained by expanding the compressed image, and the specified distant view image is mapped to the distant view map object. A program characterized by In any of claims 10 to 13,
Of the plurality of distant view images, only the compressed image of the distant view image corresponding to a given range around the virtual camera is decompressed,
The image generation unit
A program for mapping a distant view image corresponding to a position of a virtual camera from the distant view image corresponding to the given range obtained by decompression to the distant view map object. A program for image generation,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. As an image generation unit that maps to a distant view map object and generates an image that can be seen from a virtual camera in the object space,
Make the computer work,
The distant view image storage unit
Storing the plurality of distant view images as compressed images;
The image generation unit
Mapping a distant view image obtained by decompressing the compressed image to the distant view map object;
Of the plurality of distant view images, only the compressed image of the distant view image corresponding to a given range around the virtual camera is decompressed,
The image generation unit
Mapping a distant view image corresponding to the position of the virtual camera from the distant view image corresponding to the given range obtained by the expansion to the distant view map object ;
The distant view image storage unit
As a compressed image of each distant view image that should be seen from the virtual camera at each position in the object space, an object farther from the virtual camera than the position of the primitive plane of the distant view map object is drawn as a distant view object. Store compressed images,
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Program to do. In any one of Claims 1 thru | or 15,
When generating a plurality of images in which each image is displayed on each of a plurality of screens, a first image for the first screen visible from the first virtual camera and a second image visible from the second virtual camera A program for generating a second image for a screen by sharing a distant view image stored in a distant view image storage unit. In any one of Claims 1 thru | or 16.
The image generation unit
The first to Nth distant view images associated with the first to Nth (N is an integer of 2 or more) positions are read out as a distant view image corresponding to the position of the virtual camera from the plurality of distant view images. A program for mapping an image obtained by synthesizing the read first to Nth distant view images to the distant view map object. In any one of Claims 1 thru | or 17,
The distant view image storage unit
Each distant view image that should be seen when looking around the virtual camera with the virtual camera arranged at each position in the object space where the distant object is arranged is stored in association with each position in the object space,
The image generation unit
Of the plurality of distant view images stored in the distant view image storage unit, a distant view image associated with a virtual camera position is mapped to the distant view map object, and an image that can be viewed from the virtual camera in the object space is generated. The program characterized by doing.   A computer-readable information storage medium, wherein the program according to any one of claims 1 to 18 is stored. An image generation system for generating an image,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. An image generator that maps to a distant view map object and generates an image that can be viewed from a virtual camera in the object space;
Including
The distant view map object is a distant view cube map object composed of a plurality of primitive surfaces,
The distant view image storage unit
Storing a distant view image to be mapped to the distant view cube map object;
The image generation unit
Mapping the distant view image stored in the distant view image storage unit to the distant view cube map object ;
The distant view image storage unit
As each far view image that should be seen from the virtual camera at each position in the object space, an object that is farther from the virtual camera than the position of the primitive plane of the far view map object is stored as a far view object.
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Image generation system. An image generation system for generating an image,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. An image generator that maps to a distant view map object and generates an image that can be viewed from a virtual camera in the object space;
Including
The distant view image storage unit
Storing the Z value generated by the hidden surface removal process of the Z buffer method in the process of generating each distant view image that should be seen from the virtual camera at each position in the object space where the distant object is placed;
The image generation unit
When drawing the object, not only the Z value of the object but also the Z value of the distant image is used to perform hidden surface removal processing ,
The distant view image storage unit
As each far view image that should be seen from the virtual camera at each position in the object space, an object that is farther from the virtual camera than the position of the primitive plane of the far view map object is stored as a far view object.
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Image generation system. An image generation system for generating an image,
A distant view image storage unit for storing a plurality of distant view images including each distant view image to be seen from the virtual camera at each position in the object space;
A virtual camera control unit for controlling the virtual camera;
Of the plurality of distant view images stored in the distant view image storage unit, the distant view image specified by the position of the virtual camera is configured by a primitive surface arranged at a position away from the virtual camera by a given distance. An image generator that maps to a distant view map object and generates an image that can be viewed from a virtual camera in the object space;
Including
The distant view image storage unit
Storing the plurality of distant view images as compressed images;
The image generation unit
Mapping a distant view image obtained by decompressing the compressed image to the distant view map object;
Of the plurality of distant view images, only the compressed image of the distant view image corresponding to a given range around the virtual camera is decompressed,
The image generation unit
Mapping a distant view image corresponding to the position of the virtual camera from the distant view image corresponding to the given range obtained by the expansion to the distant view map object ;
The distant view image storage unit
As a compressed image of each distant view image that should be seen from the virtual camera at each position in the object space, an object farther from the virtual camera than the position of the primitive plane of the distant view map object is drawn as a distant view object. Store compressed images,
The image generation unit
A far view image corresponding to each position in an object space where a virtual camera is arranged is mapped to the far view map object from the plurality of far view images stored in the far view image storage unit. Image generation system.