JP4717622B2 - Program, information recording medium, and image generation system - Google Patents

Description

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

  In recent years, an image generation system for generating an object such as a character placed and set in a virtual three-dimensional space (hereinafter referred to as “object space”) as an image viewed from a virtual camera (a given viewpoint) has been put into practical use. Has been. Such an image generation system has come to be used in various systems as being capable of experiencing virtual reality, and is particularly important for improving entertainment and entertainment in game systems. Is being viewed.

  Conventionally, such an image generation system, for example, in order to accurately draw an object in which a gazing point is set, such as a hero character in a game (hereinafter also referred to as a gaze target object), in an image to be generated, Various image processing including whether or not drawing can be performed is performed on an object such as an obstacle (shield) disposed between the virtual camera and the object to be watched.

  In particular, recently, such an image generation system has been used as a gaze target for an obstacle object arranged between the position of a virtual camera and a gaze target such as a main character while maintaining the presence of the game. It is known that accurately draws.

Specifically, the image generation system performs a determination process to determine whether an object such as an obstacle is observed from the virtual camera so as to overlap the gaze target of the main character, and the position of the virtual camera and the gaze target When the object is determined to be in a state of being overlapped with the object, predetermined transparency processing is performed on the object (for example, Patent Document 1).
Japanese Patent No. 3141737

  However, in the above-described image generation system, the determination process for determining whether or not an object overlaps between the position of the virtual camera and the gaze target and is observed from the virtual camera must be performed for each object. In other words, the processing for generating an image increases. In addition, since such an image generation system requires a large amount of processing when there are many objects to be drawn, an image system that suppresses image processing capability can perform image formation smoothly and accurately. Is difficult.

  The present invention has been made in view of the problems as described above, and the object of the present invention is to reduce the processing burden when generating an image and to change the object according to the position of the virtual camera. An object of the present invention is to provide an image generation system that accurately draws and generates an image.

  (1) The present invention is an image generation system for generating an image that can be viewed from a virtual camera in an object space. The image generation system corresponds to a first object, a predetermined object that corresponds to the first object and is drawn so as to be transparent An object space setting unit for setting a second object having transparency in the object space, and a line-of-sight vector of the virtual camera and an object are formed when an object visible from the virtual camera set in the object space is drawn In accordance with the angle formed by the normal vector of the surface, a drawing target determining unit that determines the suitability of the surface constituting the object as a drawing target, and only the surface determined as the drawing target is drawn to generate an image. An image generation unit, and a normal vector of a surface constituting the first object and the first object The normal vector of the surface constituting the object is the angle formed between the other normal vector and the line-of-sight vector when the angle formed between the one normal vector and the line-of-sight vector of the virtual camera belongs to the first angle range. Have a relationship belonging to the second angle range, and the drawing target determining unit sets a drawing target as a drawing target in a plane in which an angle of a normal vector with respect to a line-of-sight vector of the virtual camera is within the first angle range. The present invention relates to an image generation system that performs processing that does not target a surface whose normal vector angle with respect to the camera's line-of-sight vector is within the second angle range.

  The present invention is also applicable to a program that causes a computer to function as each of the above-described units and a computer-readable information storage medium that stores such a program.

  According to the present invention, since the first object and the second object are not determined to be drawn simultaneously, either the opaque object or the translucent object is selected according to the position of the virtual camera in the object space. One object will be drawn.

  Therefore, according to the present invention, in the object space, when there is a shield that makes the gaze target invisible from the virtual camera between the virtual camera and the object that is the gaze target, By setting the second object corresponding to this, the object to be watched, such as the process of specifying the shield between the virtual camera and the object to be watched, or the process of rendering the shield semi-transparent By performing only the determination of the drawing target for each object without performing a dedicated process for visually recognizing the image, an image that allows the gaze target to be visually recognized even if the object that is the gaze target is shielded by another object is generated. be able to.

  As a result, according to the present invention, it is possible to reduce the processing burden when generating an image by eliminating the dedicated processing described above, and it is possible to visually recognize an object to be watched according to the position of the virtual camera. An image drawn accurately can be obtained.

  (2) The image generation system of the present invention further includes a texture mapping unit that performs texture mapping on the object, and the texture mapping unit is mapped to the first object when the second object is drawn. You may make it map the texture of at least any one of the same color or pattern as a texture to a 2nd object. In the program and information storage medium of the present invention, a computer may function as the texture mapping unit.

  In this way, when the second object is the drawing target, the texture of the same color or pattern as the first object is mapped, so that the presence of the first object that is not the drawing target is indirectly recognized. This makes it easier to grasp the position in the object space.

  (3) In the image generation system, the program, and the information recording medium of the present invention, the size of the second object may be set smaller than the size of the first object.

  In this way, since the drawing area of the second object is reduced, the second object can be drawn with a small amount of data processing when the range in which the position or orientation of the virtual camera changes is limited. Therefore, convenience is high.

  (4) Further, in the image generation system, the program, and the information recording medium of the present invention, the object space setting unit may change the third object when the size of the third object to which the gazing point in the virtual camera changes is changed. The second object may be set by changing the size of the object in the object space according to the size of the object.

  In this way, when the size of the third object on which the gazing point is set changes, the size of the second object projected on the screen becomes less than the screen size and an unsightly image is generated. Can be eliminated.

  (5) Further, in the image generation system, the program, and the information recording medium of the present invention, the object space setting unit is configured such that the first object is composed of a plurality of surfaces having different normal vectors. When the normal vector of each surface that constitutes belongs to the first angle range with respect to the line-of-sight vector, it is configured by a single surface having the line-of-sight vector and the normal vector belonging to the second angle range. The second object may be set in the object space.

  Usually, when an object composed of a plurality of surfaces is observed from the back side, it is often unnecessary to draw a complicated shape. In particular, when it is intended to see through the shielding object, it is sufficient if only the presence of the shielding object can be grasped.

  Therefore, when the first object is composed of a plurality of surfaces having different normal directions, the second object is composed of a single surface having the line-of-sight vector and a normal vector belonging to the second angle range. Thus, even when an object having a complicated shape is drawn, drawing can be completed with a small amount of data processing, and if the virtual camera is set on the second object side, the drawing determination Since the number of normal vectors to be processed is reduced, the burden of the drawing target determination process is reduced.

  Next, preferred embodiments of the present invention will be described with reference to the drawings.

  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 First, the configuration of an image generation system (game system) in the present embodiment will be described with reference to FIG.

  FIG. 1 is an example of a functional block diagram of the image generation system of the present embodiment. In addition, the image generation system according to 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, a VRAM, or the like. The storage unit 170 of this embodiment includes a frame buffer 172 that stores a final display image and the like, an object data storage unit 173 that stores each vertex data of the object for each object, and each object data A texture storage unit 174 for storing textures for use, and a Z buffer 176 for storing Z values at the time of object image generation processing. Note that some of these may be omitted.

  The object data storage unit 173 of the present embodiment is an object that is preset in the local coordinate system and includes vertex data such as vertex position coordinates, texture coordinates, color data, normal vectors (normal data), and α values. Data or object data including each vertex data calculated by a predetermined calculation by the processing unit 100 is stored.

  In particular, in the object data storage unit 173 of the present embodiment, an object that may be set between a gaze target object such as a character for which a gazing point is set and a virtual camera, that is, a virtual For objects that may draw other objects (objects such as characters for which a gazing point is set) placed behind the object based on the camera's line-of-sight direction, normal objects (hereinafter, “ Object data (hereinafter also referred to as “first object data”) for drawing a first object and an object corresponding to the first object data (hereinafter also referred to as “second object”). Object data for drawing a vector, each normal vector of the first object And α value indicating the transparency of an object at the time of drawing are different object data (hereinafter, referred to as. "The second object data") and, is stored.

  That is, in the object data storage unit 173 of the present embodiment, in addition to the first object data for drawing the first object recognized as the front surface of the predetermined object such as the shielding object, the back surface of the predetermined object is recognized. Second object data for drawing the second object is stored. The second object data includes vertex data corresponding to each vertex data of the first object data, and the normal vector of the first object data corresponding to the direction of the normal vector in the object space and a predetermined angle range. It is different from the above, and is composed of data for drawing an object with a predetermined transparency (preferably translucent).

  The second object data may be data constituting an object different from the first object, such as the size or coordinate position of the object, and the coordinate data is defined relative to the first object data. Each vertex data may be configured. However, each vertex data of the second object data has a sufficient size with respect to the angle of view of the virtual camera when rendered as an image viewed from the virtual camera, and the coordinate data thereof is the first It must be set within a predetermined range from the coordinate position of the corresponding vertex data in the object data, that is, within a range that can be recognized as the same object.

  Note that the normal vector defined in the second object data is opposite to the normal vector in the vertex data corresponding to the first object data in the object space direction, that is, the angle is 180 degrees different. Although it is preferable, the first object and the second object may be in an angle range that can be recognized as a front object and a back object.

  The texture storage unit 174 stores textures corresponding to the first object data and the second object data. In particular, even when the second object data is drawn in the texture storage unit 174 using the second object data such as the same color and the same pattern as the first object as the texture for the second object data, A texture that can be recognized as an object having a correspondence relationship with an object drawn by one object data is stored.

  However, when the texture is not mapped to the second object, the vertex color can be set in the object data of the second object without preparing the texture for the second object.

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

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

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

  Note that a program (data) for causing a computer to function as each unit of the present embodiment is 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 virtual camera control unit 114, and an image generation processing unit 120. Note that some of these may be omitted.

  The object space setting unit 110 includes various objects (primitive surfaces such as polygons, free-form surfaces, and subdivision surfaces) representing display objects such as characters, buildings, stadiums, cars, trees, columns, walls, and maps (terrain). (Object) is set in the object space. That is, the position and rotation angle (synonymous with direction and direction) of the object (model object) in the world coordinate system are determined, and the rotation angle (X, Y, Z axis around the position (X, Y, Z)) is determined. Arrange objects at (rotation angle).

  In particular, the object space setting unit 110 of the present embodiment sets each object in the object space based on the object data stored in the object data storage unit 173. Specifically, the object space setting unit 110 sets an object that is fixedly set in the object space based on the object data stored in the object data storage unit 173, and sets the object space in the object space. The moving object is set at a position processed by the movement / motion processing unit 112 based on the object data stored in the object data storage unit 173.

  The movement / motion processing unit 112 performs a movement / motion calculation (movement / motion simulation) of an object (such as a character, a ball, a car, or an airplane). That is, an object (moving object) is moved in the object space or an object is moved based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), or the like. Perform processing (motion, animation). Specifically, a simulation process for sequentially obtaining object movement information (position, rotation angle, speed, or acceleration) and motion information (position or rotation angle of each part object) every frame (1/60 second). I do. A frame is a unit of time for performing object movement / motion processing (simulation processing) and image generation processing.

  The virtual camera control unit 114 performs a virtual camera (viewpoint) control process for generating an image viewed from a given (arbitrary) viewpoint in the object space. Specifically, 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 shooting an object (eg, character, ball, car) from behind using a virtual camera, the virtual camera position or rotation angle (virtual camera position) is set so that the virtual camera follows changes in the position or rotation of the object. Control). In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112. Alternatively, the virtual camera may be controlled to rotate at a predetermined rotation angle or to move along a predetermined movement path. In this case, the virtual camera is controlled based on the virtual camera data for specifying the position (movement path) or rotation angle of the virtual camera. When there are a plurality of virtual cameras (viewpoints), the above-described control process is performed for each virtual camera.

  The image generation 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 it to the display unit 190. When generating a so-called three-dimensional game image, first, each vertex data (vertex position coordinates, texture coordinates, color data, normal vector, α value, etc.) of the object is input, and based on the input vertex data Vertex processing is performed. When performing the vertex processing, it is possible to perform vertex generation processing (tessellation, curved surface division, polygon division) for subdividing the polygon as necessary. In the vertex processing, geometric processing such as vertex movement processing, coordinate transformation (world coordinate transformation, camera coordinate transformation), clipping processing, or perspective transformation processing is performed, and vertices constituting the object based on the processing result Change (update, adjust) the vertex data given for. Then, rasterization (scan conversion) is performed based on the vertex data after the vertex processing, and pixel processing (fragment processing) for drawing pixels (fragments configuring the display screen) constituting the display image is performed. In the pixel processing, various processing such as texture reading (texture mapping), color data setting / change, translucent composition, anti-aliasing, etc. is performed to determine the pixel rendering color of the final display image, and the perspective transformation is performed. The drawing color of the object is output (drawn) to the frame buffer 172 (a buffer capable of storing image information in units of pixels. Drawing buffer, display buffer, back buffer, front buffer, work buffer, VRAM). That is, in pixel shading, park pixel processing is performed in which image information (color, normal, luminance, α value, etc.) is set or changed in units of pixels of the display image. Thereby, an image (frame image) observed from the virtual camera (given viewpoint) in the object space is generated. When there are a plurality of viewpoints, a frame image can be generated so that an image observed from each viewpoint can be displayed on one screen as a divided image.

  In particular, the image generation unit 120 according to the present embodiment draws an object for each object data stored in the object data storage unit 173 (specifically, for each vertex data) with reference to the viewing direction of the virtual camera. A drawing target determining unit 121 that performs a process of determining whether or not the data is used for an object, an α blending unit 122 that performs an α blending process (semi-transparent rendering process) when rendering an object, and each object to be rendered A texture mapping unit 124 for mapping the texture.

  Note that some of these may be omitted, and the drawing target determination unit 121 may be provided in addition to the image generation unit 120.

  Normally, when generating an image, the vertex data of an object that cannot be observed with respect to the viewing direction of the virtual camera is not drawn in the generated image and can be observed with respect to the viewing direction of the virtual camera. An image can be generated by drawing an object based on only the vertex data. For this reason, the drawing target determination unit 121 of the present embodiment determines whether or not the vertex of the object can be observed with respect to the viewing direction of the virtual camera based on the normal vector of each vertex data, that is, whether or not the drawing target is a drawing target. A determination process is performed to determine whether or not.

  Specifically, for each vertex data, the drawing target determining unit 121 sets a vector (hereinafter also referred to as “line-of-sight vector”) directed from the virtual camera toward a gaze point set as a gaze target such as a main character. If the inner product of each vertex data contained in each object data and the normal vector of the vertex data is calculated and the calculated value shows a predetermined condition (for example, the angle formed by the line-of-sight vector and the normal vector is a predetermined angle) If it belongs to the range), the vertex data of the normal vector used in the calculation is determined as the object data used when drawing the object.

  That is, when the object is drawn, only the surface of the object that can be seen from the virtual camera is drawn. Therefore, the drawing target determination unit 121 determines that the angle formed by the line-of-sight vector and the normal vector is 180 degrees ± 90 degrees. When it falls within the range, it is necessary to determine as a drawing target. Accordingly, the drawing target determination unit 121 of the present embodiment sets the line-of-sight vector as “V1”, the normal vector as “V2”, and the angle formed by the line-of-sight vector and the normal vector as “θ”. The angle parameter cos θ is calculated by the inner product calculation of the above, and when the angle θ is in a range of 180 ° ± 90 °, it is determined as a drawing target.

cos θ = V1 · V2 / | V1 || V2 | (1)
However, since the line-of-sight vector and the normal vector are unit vectors, | V1 | = | V2 | = 1.

  Note that the drawing target determination unit 121 according to the present embodiment performs the determination process for each vertex data, that is, for each object data, so that the object to be watched, such as a character for which a gazing point is set, and the virtual camera are used. There is a possibility of drawing an object that may be set in between, specifically, another object (an object such as a character for which a gazing point is set) placed behind the object based on the virtual camera In a certain object, determination processing is also performed on the vertex data of each of the first object data and the second object data.

  The α blending unit 122 can also perform an α blending process (usually α blending, α addition blending, α subtraction blending, or the like) based on an α value (A value).

  The α blending unit 122 performs α blending processing (normal α blending, α addition blending, α subtraction blending, or the like) based on the α value (A value). For example, in the case of normal α blending, the following processing is performed.

RQ = (1−α) × R1 + α × R2 (2)
GQ = (1−α) × G1 + α × G2 (3)
BQ = (1−α) × B1 + α × B2 (4)
On the other hand, in the case of addition α blending, the following processing is performed.

RQ = R1 + α × R2 (5)
GQ = G1 + α × G2 (6)
BQ = B1 + α × B2 (7)
However, R1, G1, and B1 are RGB components of an image (image) already drawn in the frame buffer 172, and R2, G2, and B2 are RGB components of an image to be drawn in the frame buffer 172. RQ, GQ, and BQ 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 α blending unit 122 of the present embodiment, when drawing an object based on the second object data, displays a character or other object in which a gaze point behind the object is set based on the visual line direction of the virtual camera. In order to draw, the object is rendered translucent based on the α value of the vertex data included in the second object data.

  The texture mapping unit 124 performs processing for mapping the texture (texel value) stored in the texture storage unit 174 to each object. Specifically, the texture mapping unit 124 reads the texture (surface properties such as color and α value) from the texture storage unit 174 using the texture coordinates set (given) at the vertices of the object (primitive surface). A texture that is a two-dimensional image or pattern is mapped to an object. In this case, bilinear interpolation or the like is performed as processing for associating pixels with texels or texel interpolation.

  In particular, the texture mapping unit 124 of the present embodiment generates a texture that can be recognized as the same object as the first object, such as the same color and pattern as the first object, even when the object is drawn by the second object data. Based on the mapping.

  Further, in the image generation system of the present embodiment, the image generation unit 120 can perform hidden surface removal. When using hidden surface removal, for example, while performing hidden surface removal using the Z buffer 176 in which the Z value is stored, the object is determined based on the object data determined as data to be drawn by the drawing target determination unit 124. (Primitive surface) is drawn in the frame buffer 172 to generate an image. The Z value of the image is generated (stored) on the Z buffer 176 by the Z buffer method (depth comparison method) performed at the time of the drawing process. The Z value (depth value) may be the Z value itself of the Z coordinate axis of the camera coordinate system, or may be a parameter that is mathematically equivalent to this Z value.

  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 according to the present embodiment will be described with reference to FIGS. 2-5 is a figure for demonstrating the method of this embodiment. In particular, FIG. 2 is a diagram illustrating a relationship between a virtual camera and a gaze target in an object space in which the first object and the second object are set, and FIG. 3 is a part of a wall (door) drawn in the virtual camera. It is a figure which shows direction of normal vector of. FIG. 4 is a diagram showing the relationship between the size of the object on which the gazing point is set and the size of the second object, and FIG. 5 shows the relationship between the first object and the second object having primitive surfaces with different normal vectors. It is an example which shows a relationship.

  In the present embodiment, the object to be watched (third object, gaze target object) is a moving body object that moves within a preset moving area (within the moving area of the object) in the object space, An image is generated by drawing each object set in the object space based on the position and orientation of the virtual camera that changes with the movement of the gaze target object.

  That is, the virtual camera is controlled to move as the object to be watched moves, and the position and orientation of the object to be watched in the object space and the position and orientation of the virtual camera (the direction of the line-of-sight vector). : Line-of-sight direction), an image observed from outside the moving region of the object may be generated.

  Therefore, when the virtual camera is set outside the moving area of the object in this way, it is fixedly set between the object to be watched and the virtual camera, for example, at the boundary between the moving area and the moving area. In order to draw the gaze target object so that the gaze target object is visible, the object set between the gaze target object and the virtual camera is made transparent (preferably translucent). It is necessary to devise.

  Specifically, when the virtual camera is set within the movement area of the object to be watched, even if there is a wall object fixedly set at the boundary between the movement area and the movement area, As shown in FIG. 2A, since the wall object is not set between the gaze target object and the virtual camera, there is no problem in drawing the wall object visible from the virtual camera. On the other hand, when the virtual camera is set outside the moving area of the object to be watched and there is a wall object that is fixedly set at the boundary between the moving area and the moving area, as shown in FIG. As described above, the gaze target object is shielded by the wall object, and the gaze target object cannot be observed.

  Therefore, in the present embodiment, for an object that may be set between a gaze target object such as a character for which a gazing point is set and a virtual camera, a first object for drawing an object that is originally intended to be expressed. In addition to setting one object (opaque object), a method is adopted in which a second object (semi-transparent object) set at the same position as or near to the first object is set in the object space.

  Specifically, based on the first object data, for example, the first object for drawing the original object such as the shape and color of the object and the coordinate position and orientation of the object in the object space is set in the object space. It is like that. In the method of the present embodiment, the second object is converted into the object space based on the second object data corresponding to each vertex data of the first object data and having each vertex data for transparently drawing the object. It is supposed to be set.

  In particular, the normal vector of the primitive surface constituting the first object and the normal vector of the primitive surface constituting the second object are such that the angle between one normal vector and the line-of-sight vector of the virtual camera is the first angle range. , The angle formed by the other normal vector and the line-of-sight vector has a relationship belonging to the second angle range.

  For example, as shown in FIGS. 2A and 2B, for a wall object, there is a possibility that it is set between the object to be watched and the virtual camera. When this wall object is set between the gaze target object and the virtual camera, a predetermined transparency is set so that other objects such as the gaze target object can be drawn behind the wall object. A second object having (α value) is set.

  In the method of the present embodiment, as shown in FIGS. 3A and 3B, the object of a part of the wall (door) shown in FIG. 2 is set in the direction within the moving area. A first object which is an opaque wall object consisting of a primitive surface having a normal vector S1 and a semi-transparent wall consisting of a primitive surface having a normal vector S2 set in a direction outside the moving region. A second object which is an object is set. The normal vector S1 and the normal vector S2 are obtained by calculating the difference between the normal vector and the line-of-sight vector when the angle formed by the one normal vector and the line-of-sight vector of the virtual camera belongs to the first angle range. The angles formed are set in directions different from each other by a predetermined angle range or more (preferably 180 degrees) so that the formed angle has a relationship belonging to the second angle range.

  Note that the normal vectors S1 and S2 shown in FIGS. 3A and 3B are a part of a wall (door) drawn in the virtual camera set in FIGS. 2A and 2B. ) Shows the orientation of normal vectors of opaque and translucent objects. However, in FIG. 3 (A) and FIG. 3 (B), the normal vectors S1 and S2 do not indicate the values for each vertex data, and for the sake of convenience of description, the surfaces constituting the first object and the second object The normal vector of is shown.

  On the other hand, in the method of the present embodiment, when each object set in this way is drawn, an inner product operation between the line-of-sight vector and the normal vector in each vertex data is performed, so that the line-of-sight vector of the virtual camera is obtained. Thus, it is determined whether or not the drawing target is appropriate, that is, whether or not the drawing target can be observed, and the surface of the object to be drawn is drawn to generate an image. That is, in the method of the present embodiment, a technique of drawing only the front surface by determining the front surface and the back surface according to the normal direction of the primitive surface (or polygon), so-called back face culling is used. Back face culling is a technique that has been used for the purpose of reducing the data to be drawn in order to speed up the drawing process.

  In the method of the present embodiment, as described above, the normal vector of the first object and the normal vector of the second object are one normal vector and the wall object set in FIG. Since the angle formed between the visual vector of the virtual camera belongs to the first angle range and the angle formed between the other normal vector and the visual vector belongs to the second angle range, this embodiment According to this determination processing, the image generation system according to the embodiment determines only a primitive surface constituting one of the objects as a primitive surface to be drawn.

  Specifically, when the virtual camera is set within the movement area of the object to be watched, that is, when the object is drawn from the originally observed direction, the first object (the first object is configured). (Primitive surface) is drawn, and an image is drawn with the original size, color and shape of the wall.

  On the other hand, when the virtual camera is set outside the moving area of the object to be watched and there is a wall object that is fixedly set at the boundary between the moving area and the moving area, that is, behind the object that is not originally observed When the virtual camera moves and the object is drawn from the direction of the back side, the second object (primitive surface constituting the second object) is drawn, and the object on the translucent wall is drawn. draw.

  For example, when drawing an object based on the position and orientation of the virtual camera shown in FIG. 2A, the first object on the opaque wall is drawn, and the position and orientation of the virtual camera shown in FIG. When the object is drawn based on the above, the second object on the translucent wall is drawn.

  As described above, in the method according to the present embodiment, the first object is set for an object such as a shield that is set between the virtual camera and the object to be watched in the object space and makes the watch target invisible from the virtual camera. Set the second object as well as the object.

  Therefore, according to the method of the present embodiment, it is possible to visually recognize an object to be watched, such as a process of specifying a shield between the virtual camera and the object to be watched or a process of rendering the shield semi-transparent. By only determining the drawing target for each object without performing dedicated processing, an image can be generated so that the gaze target can be visually recognized even if the object to be watched for is blocked by another object. It has become.

  As a result, it is possible to reduce the processing burden when generating an image by eliminating the dedicated processing described above, and to generate an image by accurately drawing each object suitable for the position of the virtual camera. It can be done.

  Further, the second object of the present embodiment is set in the object space with a size smaller than the size of the first object, for example, as shown in FIG. In the object space, when it is set between the virtual camera and the object to be watched, and the virtual camera is close to the object or the virtual camera does not change in the height direction of the object space, This is because the drawing range of the second object projected on the screen is narrowed by the clipping process and other processes, so that the second object can be drawn with a small amount of data.

  In addition, the size of the object (third object) for which the gaze point is set, such as the main character, is set to be variable, and the size is changed within a predetermined variable range based on a predetermined event. Sometimes it is done. In other words, the second object may be drawn in a larger size in accordance with the object of interest. In this case, as shown in FIGS. 4 (A) and 4 (B), the size of the second object in the object space is changed based on the size of the object to which the gazing point is set. It is supposed to be set. That is, the second object is set by changing the size of the second object in the object space in accordance with the maximum change amount of the object for which the gazing point is set.

  As a result, even when the second object is set to a size smaller than the first object, the size of the second object projected on the screen is smaller than the screen and cannot be drawn accurately. It can be solved. However, the image generation system of the present embodiment may read the object data of the second object having a different size and set it in the object space, or the size of the second object already set in the object space may be set to a predetermined coefficient. You may scale with.

  In the method of the present embodiment, as shown in FIG. 5, when the first object is data composed of a plurality of primitive surfaces having different normals, the second object is at least one of the primitive surfaces. May be configured by primitive surface object data composed of a single normal vector S2 that differs by a predetermined angle range or more with respect to the normal vectors S1a and S1b.

  This is because there is often no need to draw the complicated shape when the object is observed with a virtual camera from the back side of the object constituted by a plurality of primitive surfaces. As a result, this image generation system can draw an object whose transparency changes according to the line-of-sight direction of the virtual camera with a small amount of data even for an object recognized as a complicated shape. When set on the two object side, the number of normal vectors to be subjected to the drawing determination process is reduced, so that the burden of the drawing determination process is reduced.

  In addition, the object set in the first object and the second object is an object (moving body object) that moves in the object space, unlike an object that is fixed in the object space such as the above-mentioned wall object. May be. In this case, the positions of the first object and the second object in the object space are calculated by the movement / motion processing unit 112.

  In the present embodiment, the first object and the second object are set only for an object that may be set between a gaze target object such as a character for which a gaze point is set and a virtual camera. The present invention can be applied even if a character such as a main character with a fixed gaze point is present or not.

  In the present embodiment, the case where two objects of the first object and the second object are set for one object has been described. Of course, three or more objects may be set for one object. Is possible.

3. Processing of the Present Embodiment Next, a detailed processing example when drawing an object in the image generation system of the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing an operation when drawing an object in the image generation system of this embodiment.

  The following processing will be described using an object fixed on an object space such as a wall object.

  First, various data relating to an object used for image generation, such as object data and texture data, are read and transferred to the RAM or VRAM (step S1). In particular, for an object that may be set between a gaze target object such as a character for which a gaze point is set and a virtual camera, the first object data and the second object data, and the texture corresponding to each of the first object data and the second object data Are transferred to the RAM or VRAM.

  Next, each object is set in the object space (step S2). In particular, for an object that may be set between a gaze target object such as a character for which a viewpoint is set and a virtual camera, the first object and the second object data are based on the first object data and the second object data. Two objects are set in the object space.

  Next, when the position of the virtual camera serving as a reference when generating an image is determined based on the instruction data from the operation unit or the like, the line-of-sight vector and the normal line for each object based on the line-of-sight direction of the virtual camera Calculates the inner product of the vectors, determines whether the angle formed by the line-of-sight vector and the normal vector is within the first angle range or the second angle range, and determines the surface of the object to be drawn (Step S3).

  Specifically, when the angle formed by the line-of-sight vector and the normal line vector is within the predetermined first angle range, the surface is determined to be a drawing target and is formed by the line-of-sight vector and the normal vector. When the angle is within the second angle range, it is determined that the surface is not a drawing target. In particular, with respect to an object that may be set between a gaze target object such as a character for which a gazing point is set and a virtual camera, as a result, one of the first object and the second object. Is selectively determined as a drawing target surface.

  Next, the surface (object primitive) determined as the drawing target in the process of step S2 is drawn while performing the texture mapping process to generate an image (step S4). In particular, when drawing an object with the second object data, the surface of the object is drawn while performing texture mapping based on the texture of the same color or pattern as the first object.

4). Hardware Configuration Next, a hardware configuration capable of realizing the present embodiment will be described with reference to FIG. FIG. 7 is an example of a hardware configuration that can realize this embodiment.

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

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

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

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

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

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

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

  The RAM 960 serves as a work area for various processors. The DMA controller 970 controls DMA transfer between the processor and the memory. The 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. May be. Alternatively, it may be realized by both hardware and a program.

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

  Further, the present invention is not limited to that described in the above embodiment, and various modifications can be made. For example, terms (polygons, etc.) cited as broad or synonymous terms (primitive surfaces, etc.) in the description or drawings are replaced with broad or synonymous terms in the other descriptions or drawings. Can do.

  Further, the determination process and the drawing process are not limited to those described in this embodiment, and techniques equivalent to these can also be 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 a game image, and a mobile phone. it can.

The example of a functional block diagram of the image generation system of this embodiment. It is a figure for demonstrating the method of this embodiment, and is a figure which shows the relationship between the virtual camera and gaze target in the object space in which the 1st object 2nd object was set. It is a figure for demonstrating the method of this embodiment, and is a figure which shows direction of the normal vector of a part of wall (door) drawn in a virtual camera. It is a figure for demonstrating the method of this embodiment, and is a figure which shows the relationship between the size of the object in which a gaze point is set, and the size of a 2nd object. It is a figure for demonstrating the method of this embodiment, and is a figure which shows the example of the 2nd object with respect to the primitive surface from which a 1st object differs in a normal vector. The detailed example of the process of this embodiment. Hardware configuration example.

Explanation of symbols

100 processing unit, 110 object space setting unit, 112 movement / motion processing unit,
114 virtual camera control unit, 120 image generation unit, 121 drawing target determination unit,
122 α blending unit, 123 texture mapping unit, 130 sound generation unit,
160 operation unit, 170 storage unit, 172 frame buffer,
173 Object data storage unit, 174 Texture storage unit,
176 Z buffer 176, 180 information storage medium, 190 display unit,
192 sound output unit, 194 portable information storage device, 196 communication unit

Claims (9)

A program for generating an image visible from a virtual camera in an object space,
An object space setting unit that sets a first object and a second object corresponding to the first object and having a predetermined transparency for rendering transparently, in the object space;
When drawing an object that can be seen from a virtual camera set in the object space, a drawing target for a surface constituting the object according to an angle formed by a line-of-sight vector of the virtual camera and a normal vector of the surface constituting the object A drawing target determination unit that determines suitability as
As an image generation unit that draws only the surface determined to be the drawing target and generates an image, the computer functions.
The normal vector of the surface that constitutes the first object and the normal vector of the surface that constitutes the second object are such that the angle formed by one normal vector and the line-of-sight vector of the virtual camera is from the virtual camera to the object. When belonging to the first observable angle range, the angle formed by the other normal vector and the line-of-sight vector has a relationship belonging to the second angle range in which the object cannot be observed from the virtual camera ,
The drawing target determination unit
A surface whose normal vector angle with respect to the visual vector of the virtual camera is within the first angle range is a drawing target, and the angle of the normal vector with respect to the visual vector of the virtual camera is within the second angle range. A program characterized by performing processing that does not target a surface. In claim 1,
Causing the computer to function as a texture mapping unit that performs texture mapping on an object;
The texture mapping unit is
A program characterized by mapping at least one texture of the same color or pattern as a texture mapped to the first object to the second object when drawing the second object. In claim 1 or 2,
A program characterized in that the size of the second object is set smaller than the size of the first object. In claim 3,
The object space setting unit
Setting the second object by changing the size of the object in the object space in accordance with the size of the third object when the size of the third object on which the point of interest in the virtual camera is set changes. A featured program. In claim 4,
The object space setting unit
When the first object is composed of a plurality of surfaces having different normal vectors, and the normal vector of each surface constituting the first object belongs to a first angle range with respect to the line-of-sight vector, A program characterized in that a second object composed of a single plane having the line-of-sight vector and a normal vector belonging to the second angle range is set in the object space.   An information storage medium readable by a computer, wherein the program according to any one of claims 1 to 5 is stored. An image generation system for generating an image visible from a virtual camera in an object space,
An object space setting unit that sets a first object and a second object corresponding to the first object and having a predetermined transparency for rendering transparently, in the object space;
When drawing an object that can be seen from a virtual camera set in the object space, a drawing target for a surface constituting the object according to an angle formed by a line-of-sight vector of the virtual camera and a normal vector of the surface constituting the object A drawing target determination unit that determines suitability as
An image generation unit that generates an image by drawing only the surface determined to be the drawing target;
Including
The normal vector of the surface that constitutes the first object and the normal vector of the surface that constitutes the second object are such that the angle formed by one normal vector and the line-of-sight vector of the virtual camera is from the virtual camera to the object. When belonging to the first observable angle range, the angle formed by the other normal vector and the line-of-sight vector has a relationship belonging to the second angle range in which the object cannot be observed from the virtual camera ,
The drawing target determination unit
A surface whose normal vector angle with respect to the visual vector of the virtual camera is within the first angle range is a drawing target, and the angle of the normal vector with respect to the visual vector of the virtual camera is within the second angle range. An image generation system that performs processing that does not target a surface for drawing.   A program for generating an image visible from a virtual camera in an object space,
  An object space setting unit that sets a first object and a second object corresponding to the first object and having a predetermined transparency for rendering transparently, in the object space;
  When drawing an object that can be seen from a virtual camera set in the object space, a drawing target for a surface constituting the object according to an angle formed by a line-of-sight vector of the virtual camera and a normal vector of the surface constituting the object A drawing target determination unit that determines suitability as
  As an image generation unit that draws only the surface determined to be the drawing target and generates an image, the computer functions.
  The normal vector of the surface that constitutes the first object and the normal vector of the surface that constitutes the second object have an angle between one normal vector and the line-of-sight vector of the virtual camera of 180 ° ± 90 °. A first angle range that is a range, the angle formed by the other normal vector and the line-of-sight vector has a relationship that belongs to a second angle range that is outside the range of 180 degrees ± 90 degrees;
  The drawing target determination unit
  A surface whose normal vector angle with respect to the visual vector of the virtual camera is within the first angle range is a drawing target, and the angle of the normal vector with respect to the visual vector of the virtual camera is within the second angle range. A program characterized by performing processing that does not target a surface. An image generation system for generating an image visible from a virtual camera in an object space,
  An object space setting unit that sets a first object and a second object corresponding to the first object and having a predetermined transparency for rendering transparently, in the object space;
  When drawing an object that can be seen from a virtual camera set in the object space, a drawing target for a surface constituting the object according to an angle formed by a line-of-sight vector of the virtual camera and a normal vector of the surface constituting the object A drawing target determination unit that determines suitability as
  An image generation unit that generates an image by drawing only the surface determined to be the drawing target;
  Including
  The normal vector of the surface that constitutes the first object and the normal vector of the surface that constitutes the second object have an angle between one normal vector and the line-of-sight vector of the virtual camera of 180 ° ± 90 °. In the case of belonging to the first angle range that is a range, the relationship between the other normal vector and the line-of-sight vector belongs to the second angle range in which the object is outside the range of 180 ° ± 90 ° from the virtual camera Have
  The drawing target determination unit
  A surface whose normal vector angle with respect to the visual vector of the virtual camera is within the first angle range is a drawing target, and the angle of the normal vector with respect to the visual vector of the virtual camera is within the second angle range. An image generation system that performs processing that does not target a surface for drawing.

Images