JP4861862B2 - 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 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 a moving object such as a game is set is known. It is popular as a way to experience reality. In such an image generation system, there is a case where airflow control is performed to move and operate an object so as to be affected by the airflow. For example, there is a case where an object (for example, dead leaves) existing in the object space is expressed as moving and operating under the influence of an air flow generated by the movement of the moving body.
JP 2001-286676 A

  However, the conventional airflow control employs a method of calculating movement / motion that affects the airflow on an object that exists in an area that is not affected by the shape of the moving body. However, when this method is employed, it is impossible to express a fine air current according to the shape of the unevenness of the moving body.

  There is also known a method of performing a calculation of an air flow strictly and calculating a movement / motion of an object existing around the moving object based on the calculation result. However, this method requires a large processing load due to a large calculation amount.

  The present invention has been made in view of the problems as described above. The object of the present invention is to suppress the processing load of the system while moving an object existing around the moving body under the influence of an air current. The object is to provide a program, an information storage medium, and an image generation system that realistically represent the operating state.

  (1) The present invention is an image generation system that generates an image that can be seen from a given viewpoint in an object space, and an object space setting unit that sets a first object and a second object in the object space; A movement / motion processing unit that calculates at least one of movement and motion of one object and the second object; an area setting unit that sets a control area according to the position of the first object; and A parameter setting unit that sets movement / motion parameters in association with each of a plurality of grid points that divide the control area surface into a grid, and a drawing unit that generates an image viewed from a given viewpoint in the object space, , And the area setting unit includes at least a part of the periphery of the first object The movement / motion processing unit is set as the control area, and the movement / motion processing unit determines the position of the second object existing in the control area and the movement / motion parameter associated with each grid point on the control area surface. The present invention relates to an image generation system that calculates at least one of movement and movement of the second object based on the above.

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

  The “lattice” of the present invention refers to a state where the grid is divided at a predetermined interval. In the present invention, “at least part of the periphery of the first object” means at least part of the periphery of the first object, above, below, front, back, left side, and right side. .

  According to the present invention, an area including at least a part of the periphery of the first object is set as the control area, and the second mobile object existing in the control area is moved / moved based on the movement / motion parameter. Since the operation can be calculated, it is possible to perform the calculation of the first object with a simple calculation without performing the calculation of the airflow simulation and the calculation of moving and operating the second object based on the calculation result as in the prior art. It is possible to express the movement and movement of the second object existing in the area including at least a part of the surroundings under the influence of the airflow.

  For example, when expressing a state in which an air flow is generated by moving a moving body (an example of a first object), an area including at least a part of the periphery of the moving body is set as a control area, If the movement / motion parameters are set based on the movement / motion parameters, the dead leaves (an example of the second object) existing in the control area are affected by the airflow based on the set movement / motion parameters. Operations can be calculated. Further, according to the present invention, since the movement / motion parameter associated with each grid point on the control area plane can be acquired based on the position of the second object, it is compared with the calculation for performing the air flow simulation. Therefore, the amount of calculation is small and the processing load of the image processing system can be suppressed.

  (2) In the image generation system, the program, and the information storage medium of the present invention, the area setting unit sets a correction area including a range occupied by the first object, and the movement / motion processing unit You may make it perform the calculation which correct | amends the position of a said 2nd object so that the position of a 2nd object may be located outside the said correction area.

  According to the present invention, the correction area including the range occupied by the first object is set and the correction is performed so that the position of the second object is outside the correction area. It is possible to prevent the generation of an unnatural image that exists inside or the second object is embedded in the first object.

  (3) In the image generation system, the program, and the information storage medium of the present invention, the area setting unit associates a plurality of lattice points that divide the correction area surface into a lattice shape and each of the plurality of lattice points. A correction area is set on the basis of the correction parameter, and the movement / motion processing unit is based on the correction parameter associated with the position of the second object and each grid point on the correction area surface. Then, a calculation for correcting the position of the second object may be performed.

  According to the present invention, the correction parameter is acquired based on the two-dimensional positional relationship between the position of the second object and each lattice point of the correction area surface, and the correction of the second object is performed based on the acquired correction parameter. Thus, it is possible to generate an image in which the second object does not sink into the first object while reducing the amount of calculation. For example, even if the first object has a complex shape with irregularities, the second object is present outside the first object with a simple calculation without applying the processing load of the image generation system. Natural images can be generated.

  (4) In the image generation system, the program, and the information storage medium of the present invention, the area setting unit sets the correction area using a volume that includes the first object, and the movement / motion processing unit However, when at least a part of the second object exists in the volume, an operation is performed to correct the position of the second object so that the second object is located outside the volume. It may be.

  According to the present invention, since a correction operation is performed using the volume that contains the first object, a technique for strictly calculating whether or not at least a part of the second object exists in the first object is used. Compared to the above, it is possible to easily perform a correction operation.

  (5) In the image generation system, program, and information storage medium of the present invention, the parameter setting unit sets correction parameters in association with each of the plurality of grid points obtained by dividing the control area surface into a grid. The movement / motion processing unit corrects the position of the second object based on the position of the second object and the correction parameter associated with each grid point of the control area surface. You may make it perform a calculation.

  According to the present invention, not only the movement / operation parameters but also the correction parameters are set in advance in association with each of a plurality of two-dimensional lattice points obtained by dividing the control area surface into a lattice shape. Thus, the movement / operation parameter and the correction parameter can be referred to, and the processing load can be reduced.

  (6) In the image generation system, the program, and the information storage medium of the present invention, after the movement / motion processing unit calculates at least one of movement and motion of the second object, You may make it perform the calculation which correct | amends a position.

  According to the present invention, even if a part of the second object is located in the first object by calculating at least one of the movement and movement of the second object, the second object is subsequently moved to the second object. Since the calculation for correcting the position of the object is performed, it is possible to prevent generation of an unnatural image. That is, according to the present invention, it is possible to reliably prevent an unnatural image such that the second object sinks into the first object, and to always generate a natural image.

  (7) In the image generation system, the program, and the information storage medium of the present invention, the area setting unit is a predetermined area in a direction perpendicular to the control area surface and the control area surface, around the first object. An area surrounded by a range may be set as the control area.

  According to the present invention, since the movement / motion based on the movement / motion parameter is performed only on the second object existing in the control area, the amount of calculation can be suppressed.

  (8) In the image generation system, the program, and the information storage medium of the present invention, the area setting unit sets the common control area for a plurality of types of the first objects, and the parameter setting unit A common movement / motion parameter may be set in association with each of the plurality of grid points that divide the common control area surface into a grid for a plurality of types of the first objects. .

  According to the present invention, since it is not necessary to set movement / motion parameters for each of a plurality of types of first objects, the storage area is compared with a case where movement / motion parameters are set for each of a plurality of types of first objects. Can be saved.

  (9) In the image generation system, the program, and the information storage medium of the present invention, the movement / motion processing unit sets the movement / motion parameters set at the respective grid points based on the position of the second object. And at least one of movement and movement of the second object may be calculated based on the interpolated value.

  According to the present invention, since at least one of the movement and movement of the second object can be calculated based on the value obtained by interpolating the movement / motion parameter set at each grid point, the control area surface is roughly grid-like. The movement / operation parameters can be set in association with each of the plurality of grid points divided into the two. As a result, there is no need to finely divide the control area surface into a grid and set grid points densely, so the data amount of movement / operation parameters can be reduced, and the storage area can be saved. .

  (10) In the image generation system, the program, and the information storage medium of the present invention, the object space setting unit is a coordinate that defines the position of the first object in the local coordinate system of the first object. The first object is set in the object space by converting it into a position in the system, the area setting unit sets the control area in the local coordinate system, and the parameter setting unit sets the control area plane. A plurality of lattice points that divide the image into a lattice shape are set in the local coordinate system, and the movement / motion processing unit converts the position of the second object set in the object space into the local coordinate system. The calculation may be performed based on the converted position.

  According to the present invention, the movement / motion parameter can be set regardless of the position of the first object in the object space (world coordinate system), and the position of the second object in the object space It is possible to easily calculate the movement / motion and correction of the second object simply by converting to the local coordinate system of the second object. In other words, according to the present invention, the control area is set every time the first object moves in the object space, and the complexity of the arithmetic processing for moving / moving or correcting the second object can be avoided. The processing load on the image generation system can be reduced.

1. Configuration Hereinafter, the present 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.

  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 used by the player to input operation data of the moving body, and the function thereof can be realized by a lever, a button, a steering wheel, 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 (VRAM) or the like.

  The storage unit 170 performs processing for storing various data. The main storage unit 172 can be used as a work area used in the processing unit 100. In particular, the main storage unit 172 of the present embodiment can store movement / operation parameters and correction parameters set by the parameter setting unit 116. The drawing buffer 174 can store image information.

  The object data storage unit 176 can store object data. In particular, the object data storage unit 176 of the present embodiment can store the object data of the first object (moving body) and the second object (dead leaves, snow, rain). Note that when the first object is a moving object, a plurality of types of moving objects can be stored.

  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 medium 194 stores player personal data, game save data, and the like. Examples of the portable information storage medium 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. The processing unit 100 performs various processes using the main storage unit 172 in the storage unit 170 as a work area. The functions of the processing unit 100 are hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs. Can be realized.

  The processing unit 100 includes an object space setting unit 110, a movement / motion processing unit 112, an area setting unit 114, a parameter setting unit 116, a drawing unit 120, and a sound generation unit 130. Note that some of these may be omitted.

  The object space setting unit 110 represents display objects such as a moving object, an object, particles, dead leaves, snow, rain, a character, a building, a stadium, a car, an airplane, a ship, a submarine, a tree, a pillar, a wall, and a map (terrain). Various objects (objects composed of primitives such as polygons, free-form surfaces or subdivision surfaces) are arranged 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. In particular, in the present embodiment, a process of placing the first object (moving body) and the second object (dead leaves, snow, rain) stored in the object data storage unit 176 of the storage unit 170 in the object space is performed. .

  In particular, the object space setting unit 110 of the present embodiment can set the first object in the object space by converting the position of the first object in the local coordinate system of the first object into the object space. Also, the second object can be set in the object space by converting the position of the second object in the local coordinate system of the second object into the object space.

  The movement / motion processing unit 112 performs a movement / motion calculation (movement / motion simulation) of an object (car, train or airplane, dead leaves, snow, rain, etc.). That is, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), or the like, the object is moved in the object space, or the object is moved (motion, animation). ) Process. Specifically, object movement information (position, rotation angle, speed, or acceleration) and motion information (position or rotation angle of each part that constitutes the object) are sequentially transmitted every frame (1/60 seconds). Perform the required simulation process. A frame is a unit of time for performing object movement / motion processing (simulation processing) and image generation processing.

  In particular, in the present embodiment, at least one of movement and movement of the first object and the second object is calculated. More specifically, the movement / motion processing unit 112 of the present embodiment is set by the position of the second object existing in the control area set by the area setting unit 114 and the parameter setting unit 116 described later. Based on the movement / motion parameter associated with each grid point on the control area surface, at least one of movement and motion of the second object is calculated.

  In addition, the movement / motion processing unit 112 of the present embodiment performs a calculation for correcting the position of the second object so that the position of the second object is located outside the correction area set by the area setting unit 114. Do. More specifically, the calculation for correcting the position of the second object is a correction parameter associated with the position of the second object and each grid point of the correction area plane set in the parameter setting unit 116 described later. Based on the above, a calculation for correcting the position of the second object can be performed. In the parameter setting unit 116, when the correction parameter is set in association with each of a plurality of grid points obtained by dividing the control area surface into a grid, the position of the second object and each grid of the control area surface are set. An operation for correcting the position of the second object may be performed based on a correction parameter associated with a point.

  Further, in the calculation for correcting the position of the second object of the movement / motion processing unit 112 of the present embodiment, the area setting unit 114 sets a correction area using the volume containing the first object, and the second object When at least a part of the object exists in the volume, an operation for correcting the position of the second object so that the second object is located outside the volume may be performed.

  In addition, the movement / motion processing unit 112 according to the present embodiment may perform calculation for correcting the position of the second object after calculating at least one of movement and motion of the second object.

  Further, the movement / motion processing unit 112 of the present embodiment interpolates movement / motion parameters based on the position of the second object, and calculates at least one of movement and motion of the second object based on the interpolated value. May be.

  In addition, the movement / motion processing unit 112 of the present embodiment converts the position of the second object set in the object space into the local coordinate system of the first object, and based on the converted position, You may make it perform the calculation of a movement and operation | movement, and the calculation of correction | amendment. More specifically, the calculation is performed using the determinant M for converting the position (coordinate value) of the local coordinate system of the first object into the position (coordinate value) of the object space (world coordinate system). That is, the second object in the local coordinate system of the first object is multiplied by the inverse matrix of the determinant M by the position (coordinate value) of the second object set in the object space (world coordinate system). The position (coordinate value) can be obtained. Then, based on the obtained position, the second object can be simply moved / moved and corrected. That is, each time the first object moves in the object space, the amount of calculation can be remarkably reduced as compared with a complicated calculation process that controls the movement and movement of the second object in the object space.

  The area setting unit 114 sets a given area according to the position of the first object. In particular, the area setting unit 114 of the present embodiment sets the control area according to the position of the first object. For example, an area including at least a part of the periphery of the first object can be set as the control area.

  Specifically, an area around the first object and surrounded by the control area plane and a predetermined range in the direction perpendicular to the control area plane can be set as the control area. Moreover, you may set a front part and a side part as a control area with respect to the advancing direction among the circumference | surroundings of a 1st object. Further, when the first object is a car, a part of the surroundings of the car where an upward air flow is likely to occur (for example, a windshield part of the car) may be set as the control area.

  In addition, the area setting unit 114 of the present embodiment can set a common control area for a plurality of types of first objects. For example, when the first object is a car, the same control area can be set according to various types of cars such as a passenger car, a sports car, a bus, and a truck. This is because the storage area can be saved as compared with the case where the control area is set for each vehicle type.

  Further, the area setting unit 114 according to the present embodiment can set a correction area including a range occupied by the first object. The correction area may be set based on a plurality of two-dimensional lattice points that divide the correction area surface into a lattice shape and correction parameters associated with each of the plurality of two-dimensional lattice points. it can. The correction area may be set using a volume containing the first object. Here, the volume can be a solid having a simple shape such as a sphere (bounding sphere) or a rectangular parallelepiped (bounding box) surrounding the first object. Note that the area setting unit 114 of the present embodiment may set the correction area using a volume that represents the outline of the first object. For example, when the first object is a “sphere with a needle”, the correction area may be set using the volume of a sphere (bounding sphere) ignoring the needle portion.

  Further, the area setting unit 114 of the present embodiment can set the control area in the local coordinate system of the first object. That is, the object space setting unit 110 of the present embodiment sets the first object in the object space by converting the position of the first object in the local coordinate system of the first object into the object space. Then, the area setting unit 114 of the present embodiment sets a control area in the local coordinate system at that time. In this way, since it is not necessary to calculate the movement / motion of the second object in the object space, the amount of calculation can be suppressed. Similarly, the calculation amount may be reduced by setting the correction area in the local coordinate system of the first object.

  The parameter setting unit 116 sets parameters used for the processing unit 100 to calculate. For example, parameters used for calculating movement / motion of the first object and the second object are set.

  In particular, the parameter setting unit 116 of the present embodiment can set movement / operation parameters in association with each of a plurality of grid points that divide the control area surface into a grid, based on the control area. Here, the control area plane can be a plane in a predetermined range composed of two coordinate axes.

  In particular, the parameter setting unit 116 according to the present embodiment determines a plurality of grid points that divide the control area surface in a grid pattern based on the control area set in the local coordinate system of the first object. Can be set to coordinate system. That is, the object space setting unit 110 of the present embodiment sets the first object in the object space by converting the position of the first object in the local coordinate system of the first object into the object space. A control area plane is set in the local coordinate system, and a plurality of grid points that divide the control area plane into a grid are set. In this way, based on the position of the second object (X and Z coordinate values) existing in the control area and the position of each grid point (X and Z coordinate values), the movement / motion parameter is set. And the movement / motion of the second object can be calculated based on the obtained movement / motion parameters. For example, the moving speed of the second object can be calculated based on the acquired movement / motion parameter, and the second object can be moved based on the calculated moving speed.

  In addition, the parameter setting unit 116 according to the present embodiment associates a plurality of types of first objects with a common movement / motion parameter corresponding to each of a plurality of grid points that divide a common control area surface into a grid pattern. May be set. This is because the storage area used in the image generation system of the present embodiment can be saved.

  In addition, the parameter setting unit 116 according to the present embodiment can set the correction parameter in association with each of a plurality of grid points that divide the correction area surface into a grid. Here, the correction area plane can be a plane in a predetermined range composed of two coordinate axes. For example, it can be a plane in a predetermined range constituted by an X coordinate and a Z coordinate in the local coordinate system of the first object. The correction area surface can be set based on the first object. For example, it can be set to include a point (X, Z) constituting the first object.

  In particular, the parameter setting unit 116 of the present embodiment is based on the positional relationship between the position of the second object (X and Z coordinate values) and the position of each lattice point (X and Z coordinate values) on the correction area surface. Thus, the position of the second object can be corrected. In addition, when dividing | segmenting a correction area surface into a grid | lattice form, you may make it divide | segment by the method different from the case where a control area plane is divided | segmented into a grid | lattice form. For example, the correction area surface may be divided more finely than the control area surface, and the correction parameter may be stored in association with each grid point.

  Further, when setting the correction parameter for each of the plurality of types of first objects, the parameter setting unit 116 of the present embodiment sets the common correction parameter in association with the grid points of the common correction area surface. However, it is desirable to prepare different correction area planes and set correction parameters in association with each of a plurality of grid points divided in a grid pattern for each first object. This is because the correction along the shape of the first object can be performed more accurately if the correction parameter is set according to the shape of the first object.

  In addition, the parameter setting unit 116 of the present embodiment can set the correction parameter using the control area surface without setting the correction area surface. That is, not only the movement / operation parameters but also the correction parameters may be set in association with each grid point on the control area surface.

  The virtual camera control unit performs control processing of the virtual camera (viewpoint) for generating an image that can be seen 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 an object (eg, character, ball, car) is photographed from behind using a virtual camera, the position or rotation angle of the virtual camera (the direction of the virtual camera is set so that the virtual camera follows changes in the position or rotation of the object. ) To control. In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112. Alternatively, control for rotating the virtual camera at a predetermined rotation angle or control for moving the virtual camera along a predetermined movement path may be performed. 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 control process is performed for each virtual camera.

  The drawing unit 120 performs drawing processing based on the results of various processing (game processing) performed by the processing unit 100, thereby generating an image and outputting the image to the display unit 190. When a so-called three-dimensional game image is generated, first, vertex data (vertex position coordinates, texture coordinates, color data, normal vector, α value, etc.) of each vertex defining a display object (object, model) is included. Display object data (object data, model data) is input, and vertex processing is performed based on vertex data included in the input display object data. When performing the vertex processing, vertex generation processing (tessellation, curved surface division, polygon division) for re-dividing the polygon may be performed as necessary. In vertex processing, geometry processing such as vertex movement processing, coordinate transformation (world coordinate transformation, camera coordinate transformation), clipping processing, perspective transformation, or light source processing is performed, and the display object is configured based on the processing result. The given vertex data is changed (updated, adjusted) for the vertex group. Then, rasterization (scan conversion) is performed based on the vertex data after the vertex processing, and the surface of the polygon (primitive) is associated with the pixel. Subsequent to rasterization, pixel processing (fragment processing) for drawing pixels constituting an image (fragments constituting a display screen) is performed. In pixel processing, various processes such as texture reading (texture mapping), color data setting / changing, translucent composition, anti-aliasing, etc. are performed to determine the final drawing color of the pixels that make up the image, and perspective transformation is performed. The drawing color of the object is output (drawn) to the drawing buffer 174 (buffer that can store image information in units of pixels; VRAM, rendering target). That is, in pixel processing, per-pixel processing for setting or changing image information (color, normal, luminance, α value, etc.) in units of pixels is performed. Thereby, an image that can be seen from the virtual camera (given viewpoint) set in the object space is generated. Note that when there are a plurality of virtual cameras (viewpoints), an image can be generated so that an image seen from each virtual camera can be displayed as a divided image on one screen.

  The vertex processing and pixel processing performed by the drawing unit 120 are realized by hardware that enables polygon (primitive) drawing processing to be programmed by a shader program written in a shading language, so-called programmable shaders (vertex shaders and pixel shaders). May be. Programmable shaders can be programmed with vertex-level processing and pixel-level processing, so that the degree of freedom of rendering processing is high, and the expressive power can be greatly improved compared to fixed rendering processing by hardware. .

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

  In the geometry processing, processing such as coordinate conversion, clipping processing, perspective projection conversion, or light source calculation is performed on the display object. Then, display object data after geometric processing (after perspective projection conversion) (position coordinates of vertex of the display object, texture coordinates, color data (luminance data), normal vector, α value, etc.) is stored in the main storage unit 172. Saved.

  Texture mapping is a process for mapping a texture (texel value) stored in the storage unit 170 to a display object. Specifically, the texture (surface properties such as color (RGB) and α value) is read from the storage unit 170 using texture coordinates or the like set (given) at the vertex of the display object. Then, a texture that is a two-dimensional image is mapped to a display object. In this case, processing for associating pixels with texels, bilinear interpolation or the like is performed as texel interpolation.

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

  α blending (α synthesis) is a translucent synthesis process (usually α blending, addition α blending, subtraction α blending, or the like) based on an α value (A value). For example, in normal α blending, a process for obtaining a color obtained by combining two colors by performing linear interpolation with the α value as the strength of synthesis is performed.

  The α value is information that can be stored in association with each pixel (texel, dot), and is, for example, plus alpha information other than color information indicating the luminance of each RGB color component. The α value can be used as mask information, translucency (equivalent to transparency and opacity), bump information, and the like.

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

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

2. 2.1 Method of Second Embodiment 2.1 Description of Second Object Movement / Motion Calculation Method In the image generation system of the present embodiment, an area including at least a part of the periphery of a moving object (an example of a first object) Is set as the control area, and for the dead leaves (an example of the second object) existing in the control area, the movement / motion parameter associated with each lattice point of the control area plane set based on the control area Based on this, a method for calculating movement / motion (a method for calculating at least one of movement and motion) is employed. In this way, it is possible to realistically represent how the dead leaves existing around the moving body move and operate under the influence of the air current while suppressing the processing load of the image generation system.

  First, an example of setting a control area will be described. The control area is an area where special processing based on movement / motion parameters is performed on the second object. In the present embodiment, a control area for controlling the movement / motion of dead leaves is set in order to express the movement / motion of dead leaves affected by the airflow generated with the movement of the moving body.

  In the present embodiment, the moving body is set in the object space by converting the position (coordinate value) of the moving body in the local coordinate system into the position (coordinate value) of the object space (world coordinate system). Then, a control area is set in the local coordinate system at that time.

  Here, in the present embodiment, the relationship between the local coordinate system and the object space (world coordinate system) in the process of generating an image to be finally output will be described with reference to FIGS. Then, as shown in FIGS. 2A and 2B, the local coordinate system (modeling coordinate system) converts each object including moving objects and dead leaves into an object space (world coordinate system) representing the entire scene. Perform coordinate transformation. That is, as shown in FIGS. 2A and 2B, the coordinate values of the local coordinate system of the moving object and dead leaves are subjected to coordinate conversion of enlargement / reduction, rotation, and translation, as shown in FIG. 2C. Perform coordinate conversion to convert to world coordinate values. Then, in the object space (world coordinate system), objects such as moving objects and dead leaves are arranged, and an image that can be seen from a given viewpoint in the object space is generated.

  That is, in the present embodiment, the control area is set in the local coordinate system of the moving object to be coordinate-converted into the world coordinate system. In this way, the control area can be set regardless of the position of the moving body in the object space. In other words, if the control area is set in the local coordinate system of the moving object, the movement / operation parameter is associated with each of a plurality of grid points obtained by dividing the control area surface indicated by the coordinate values of the local coordinate system described later into a grid pattern. As a result, the movement / motion parameters for controlling the movement / motion of dead leaves can be uniquely set regardless of the position of the moving object in the world coordinate system (object space). . In short, it is possible to avoid the troublesomeness of setting the movement / motion parameters each time the moving body moves in the object space.

  Concretely, it demonstrates using FIG. 3 (A) which showed the example in a world coordinate system, and FIG. 3 (B) which showed the example in a local coordinate system.

  For example, as shown in FIG. 3A, in the world coordinate system, when the moving object OB1 sets the control area CA according to the position on the hill (point P) or the position on the hill (point Q). The movement / operation parameters are set according to the positions of the point P and the point Q of the moving object OB1, which increases the amount of data and calculation processing, and increases the processing load of the image generation system.

  On the other hand, as shown in FIG. 3B, if the control area CA is set in the local coordinate system of the moving object OB1, even if the moving object freely moves in the world coordinate system, the movement / operation parameters are uniquely set. be able to. That is, even if the moving object OB1 exists at either the point P or the point Q in FIG. 3A, it is not necessary to reset the movement / operation parameters, and the data amount and the processing amount can be suppressed.

  Furthermore, if the control area is set in the local coordinate system of the moving body in this way, the simulation calculation of the airflow control is performed by inversely transforming the dead leaves existing in the object space (world coordinate system) into the local coordinate system of the moving body. Can be easily performed.

  For example, if the control area is set in the world coordinate system, as shown in FIG. 3A, the moving object OB1 may be located at either the P point or the Q point. Whether or not the dead leaf OB2 exists in the control area CA with respect to the dead leaf OB2 is determined based on the control area CA set according to the position of the moving area. Will be performed. That is, every time the position of the moving object OB1 changes, the relative positional relationship between the dead leaf OB2 and the control area CA is calculated according to the change in the control area CA, and the movement / operation of the dead leaf OB2 is calculated. It will be.

  On the other hand, according to the present embodiment, even if the moving object OB1 exists at either the P point or the Q point, if the position of the moving object OB1 in the local coordinate system is simply obtained with respect to the dead leaves OB2, It is possible to easily determine whether or not the dead leaf OB2 exists in the control area CA and to calculate the movement / operation. In short, since the control area CA is set without being influenced by the change in the position of the moving object OB1 in the object space, as a result, complicated processing for calculating the relative positional relationship between the dead leaves OB2 and the control area CA is performed. It can be avoided.

  Next, a control area setting method in the image generation system of the present embodiment will be described with reference to FIG. 4. The control area is set to an area including at least a part of the periphery of the moving body. At least a part of the periphery of the moving body means at least a part of the upper, lower, front, rear, left side, and right side of the periphery of the moving body. For example, with reference to FIGS. 4A and 4B, the upper area around the moving body refers to the area indicated by A in FIGS. 4A and 4B, and the lower area around the moving body refers to 4 (A) and 4 (B), the front of the periphery of the moving body means the area shown in C of FIGS. 4 (A) and 4 (B), and the back of the periphery of the moving body is the figure. This refers to the area indicated by D in 4 (A) and (B). Further, the left side of the moving body refers to the area indicated by E in FIGS. 4A and 4B, and the right side of the moving body refers to the area indicated by F in FIGS. 4A and 4B. As shown in FIG. 4, the upper, lower, front, rear, left side, and right side boundary portions around the moving body may be slightly shifted or may be set ambiguously. Good.

  The control area may be an area around the moving body. For example, when it is desired to express the airflow around the moving body generated by the movement of the moving body, a control area CA is set around the moving body OB1 as shown in FIGS.

  Also, as shown in FIGS. 6A and 6B, an area around the moving body, which is a rear portion area of the moving body OB1 (a so-called slipstream area that is a rear portion with respect to the traveling direction of the moving body OB1). An area excluding SA) can be set as the control area CA. For example, as shown in FIGS. 6 (A) and 6 (B), when the moving body OB1 moves in the direction of the arrow, the slip stream area SA is usually a part where the air resistance becomes weak, so the moving body OB1 moves. The airflow generated by Therefore, the area excluding the slip stream area in the area around the moving body can be set as the control area CA.

  Next, a method for setting a movement / motion parameter for moving / moving the second object existing in the control area will be described with reference to FIGS.

  As shown in FIG. 7, in the local coordinate system of the moving object OB1, it is surrounded by the moving object OB1, and 0 <= X <= 3, 0 <= Y <= 4, and 0 <= Z <= 5. This area is set as the control area CA.

  Then, the control area plane CP is set based on the control area CA set in the local coordinate system of the moving object OB1. As shown in FIG. 7, the control area CA is a range including (X, Z) surrounded by 0 <= X <= 3 and 0 <= Z <= 5 around the moving body OB1. Therefore, the control area plane CP is set as a plane including 0 <= X <= 3 and 0 <= Z <= 5 as shown in FIG. The control area plane CP may be set in a wider range than 0 <= X <= 3 and 0 <= Z <= 5.

  Next, the control area plane CP is divided into a lattice shape. For example, in FIG. 8A, the moving object OB1 is divided in a grid pattern at intervals of a size “1” with respect to the X axis and the Z axis of the local coordinate system. In addition, when dividing | segmenting into a grid | lattice form, if it can divide | segment at a predetermined interval, the magnitude | size of an interval will not be ask | required. For example, it may be divided at intervals of size “0.5”.

  The movement / motion parameter table is associated with each grid point (X, Z) indicated by (X, Z) in the local coordinate system of the moving object OB1 obtained by dividing the control area plane CP into a grid. Set parameters.

  FIG. 9A shows an example in which speed parameters (an example of movement / motion parameters) in the height direction for moving in the height direction (Y-axis direction) with respect to the dead leaves OB2 are set.

  For example, as shown in FIG. 7, when the dead leaf OB2 is moved so that an updraft is generated in the windshield portion of the moving body OB1, and the dead leaf OB2 falls in a portion other than the windshield of the moving body OB1. The movement / operation parameters are set as follows.

  First, in the local coordinate system of the moving object OB1, the grid point of the control area plane CP corresponding to the windshield portion of the moving object OB1 is specified. In the example of FIG. 7, the lattice points of the control area plane CP corresponding to the windshield portion of the moving body OB1 are (X, Z) = (1, 3), (X, Z) = (2, 3). .

  Then, a velocity parameter in the height direction (an example of a movement / motion parameter) is set in the movement / motion parameter table in association with the grid points of the control area plane CP. For example, as shown in FIG. 9A, (X, Z) = (1, 3), (X, Z) of the movement / operation parameter table corresponding to the lattice points of the control area plane CP corresponding to the windshield portion. ) = (2, 3) The velocity parameter in the height direction is set to “1”. Then, the velocity parameter in the height direction corresponding to the other lattice point (X, Z) is set to “0”.

  In the example of the movement / motion parameter described above, the example of setting the velocity parameter in the height direction has been described. However, for example, a velocity vector (an example of the movement / motion parameter) may be set. Specifically, an example in which a velocity vector is set in the movement / motion parameter table will be described with reference to FIG.

  For example, when it is desired to express a state in which an updraft is generated in the windshield portion of the moving body OB1 as shown in FIG. 7, for example, the dead leaf OB2 is moved obliquely upward, and the portion other than the windshield of the moving body OB1 Then, when it is desired to express how the dead leaf OB2 falls, a velocity vector (an example of a movement / operation parameter) can be set as follows.

  FIG. 9B shows an example in which movement / operation parameters are set when the dead leaf OB2 moves obliquely upward. For example, velocity vectors are set in association with lattice points (X, Z) = (1, 3) and (X, Z) = (2, 3) corresponding to the windshield portion of the moving object OB1. For example, the value of the velocity vector corresponding to the lattice point (X, Z) = (1, 3) and (X, Z) = (2, 3) is set to (x, y, z) = (0, 1, − Set to 1). On the other hand, velocity vectors of lattice points other than lattice point (X, Z) = (1, 3) and (X, Z) = (2, 3) are set to zero.

  Thus, if the movement / operation parameters (the velocity parameter in the height direction in the example of FIG. 9A and the velocity vector in the example of FIG. 9B) are set in advance, the movement / operation parameters set as described later are set. Since the dead leaf OB2 can be easily calculated based on the operation parameter, the processing load can be suppressed as compared with the conventional method of strictly calculating the airflow.

  As shown in the example of FIG. 6, when the area around the moving object OB1 and excluding the slip stream area SA is set as the control area CA, the control area CA occupies (X, Z). The control area plane CP is set so as to include the position of, and movement / operation parameters are set to the grid points corresponding to the points (X, Z) constituting the control area CA among the grid points of the control area plane CP. The movement / operation parameters may not be set at the lattice points that do not correspond to the points (X, Z) constituting the control area CA. Further, a predetermined value (NULL value or default value) may be set to grid points that do not correspond to the points (X, Z) constituting the control area CA.

  Next, a second object movement / motion calculation method based on the movement / motion parameters of the image generation system according to the present embodiment will be described.

  More specifically, the dead leaf OB2 (an example of the second object) existing in the object space is inversely transformed into the local coordinate system of the moving object OB1, and the position of the dead leaf OB2 is obtained. On the basis of the movement / motion parameter corresponding to, the current movement / motion value of the dead leaf OB2 is approximated to the movement / motion parameter value. The movement / motion parameter may be added to and multiplied by the current movement / motion value of the dead leaf OB2.

  Here, approaching the value of the movement / motion parameter of the present embodiment may be set to the value of the movement / motion parameter, or the value of the current movement / motion (for example, speed) of the dead leaf OB2 A difference from the value of the operation parameter is obtained, and a value obtained by multiplying the obtained difference value by a coefficient is added to the current value of the dead leaf OB2.

  For example, the case of acquiring the velocity parameter in the height direction shown in FIG. 9A will be described as an example. As shown in FIG. 8A, the dead leaf OB2 is (X, Z) = (2, 3). If it exists at the position, the velocity parameter in the height direction associated with the lattice point (X, Z) = (2, 3) is acquired from the movement / motion parameter table. For example, in the example of FIG. 9A, since the value of the acquired speed parameter is “1”, a process of approaching “1” is performed. When the current upward speed of the dead leaf OB2 is “0.5”, the difference value “0...” Between the speed parameter value “1” and the current speed “0.5” of the dead leaf OB2. 5 ”is multiplied by a coefficient“ 0.5 ”. Then, “0.75”, which is a value obtained by adding the obtained value “0.25” to the current speed “0.5” of the dead leaf OB2, is the speed of the dead leaf OB2 that is finally obtained. Then, based on the speed “0.75” of the dead leaf OB2, the dead leaf OB2 is moved upward. As a result, for example, as shown in FIG. 8B, it can be expressed that the dead leaf OB2 moves and operates in the V1 direction (upward direction).

  Further, the case where the velocity vector shown in FIG. 9B is acquired will be described as an example. When the dead leaf OB2 exists at the position (X, Z) = (2, 3), the lattice point (X, Z ) = (2,3) is performed so as to approach the speed vector value “(x, y, z) = (0, 1, −1)”. Here, when the current velocity vector of the dead leaf OB2 is (x, y, z) = (0, 1, 0), “(x, y, z) = (0, 1, −1)”. Process to bring it close to. Specifically, when the coefficient is obtained as “0.5”, (x, y, z) = (0, 1, −0.5) is obtained as the velocity vector of the dead leaf OB2. The dead leaf OB2 is based on (x, y, z) = (0, 1, −0.5), for example, as shown in FIG. 8B, the dead leaf OB2 is in the V2 direction (obliquely upward direction). It can be expressed to move and operate.

  As described above, in the image generation system of the present embodiment, the movement / operation parameters are acquired based on the positional relationship between the position of the dead leaf OB2 and each lattice point of the control area plane CP in the local coordinate system of the moving object OB1. Since the movement / motion of the dead leaf OB2 is calculated based on the acquired movement / motion parameter, the calculation is simpler than the conventional method for calculating the movement / motion of the dead leaf based on the simulation calculation of the airflow. It is possible to calculate movement and movement caused by the airflow of dead leaves. For example, the dead leaf OB2 is moved so that an ascending airflow is generated in the windshield portion of the moving body OB1, and the manner in which the dead leaf OB2 falls in a portion other than the windshield of the moving body OB1 can be realistically expressed.

  In addition, when the position of the dead leaf reversely converted to the local coordinate system of the moving object OB1 exists outside the control area CA, the calculation of the movement / motion based on the movement / motion parameter may be prevented. Good. This is because the processing load of the image generation system can be suppressed by reducing the amount of calculation.

  That is, in this embodiment, it is determined whether or not the position of the dead leaf OB2 inversely transformed into the local coordinate system of the moving object OB1 exists in the control area CA, and then the position of the dead leaf OB2 and each lattice point The movement / motion is calculated based on the movement / motion parameters associated with.

  For example, as shown in FIG. 7, in the local coordinate system of the moving object OB1, the control area CA is around the moving object OB1, and 0 <= X <= 3, 0 <= Y <= 4, 0 < If the area is surrounded by = Z <= 5, the dead leaves OB2 ′ existing at Y> 4 are outside the control area CA, and therefore, the movement / motion calculation based on the movement / motion parameters is not performed. To. On the other hand, since the dead leaf OB2 exists in the control area, the movement / operation is calculated based on the movement / operation parameters.

  In addition, since the control area CA of the present embodiment is set to at least a part of the periphery of the moving body, when the position of the dead leaf exists inside the moving body, the dead leaf is obtained by performing a correction calculation described later. After the position is corrected to an appropriate position, the movement / motion may be calculated.

  If the position (X, Z) of the dead leaf OB2 does not exist on any grid point (X, Z) of the control area plane CP, a plurality of movement / operation parameters are based on the position of the dead leaf OB2. May be interpolated, and the movement / operation of the dead leaf OB2 may be calculated based on the interpolated value. In this way, by dividing the control area plane CP roughly in a grid pattern, it is possible to reduce the data amount of movement / operation parameters associated with each grid point.

  More specifically, the movement / operation parameter is acquired based on the position of the dead leaf OB2, and the value obtained by linear interpolation is acquired. For example, in FIG. 10, linear interpolation is performed on the coordinate values (values consisting of X and Z) projected on the control area surface of the position P0 of the dead leaves OB2 and the movement / motion parameters respectively associated with the plurality of grid points P1 to P4. The calculated value may be obtained, and the movement / motion may be calculated based on the obtained value.

  In the example of the movement / motion parameter table described above, the example in which the velocity parameter in the height direction is stored and the example in which the velocity vector is stored have been described. However, the movement amount parameter and the acceleration parameter may be stored. Further, each of a plurality of parameters (speed parameter, acceleration parameter, etc.) may be stored using individual tables (speed parameter table, acceleration parameter table). Further, the movement / operation parameter may be set based on at least one of the moving speed, moving direction, and rotating direction of the moving body. For example, the movement / operation parameters may be set separately for a case where the moving body is low speed and a case where the mobile body is high speed. Further, when the moving body also moves and moves, the moving body may set movement / operation parameters corresponding to the back. Further, when the moving body spins, movement / operation parameters corresponding to the rotation direction of the moving body may be prepared. For example, a velocity vector that rotates about the center of gravity of the moving object can be stored in association with each lattice point on the control area surface.

2.2 Description of Calculation Method for Correcting Position of Second Object Next, a method for calculating calculation of the second object will be described. In the image generation system of the present embodiment, an area including at least a part of the periphery of a moving body (an example of a first object) is set as a control area, and dead leaves (an example of a second object) existing in the control area Move and move with respect to. However, if the uniform processing is performed on dead leaves existing in the control area based on the movement / operation parameters, an image in which the position of the dead leaves exists at an inappropriate position is expressed. There is a case.

  For example, as shown in FIG. 11A, there is a possibility that an image in which the moving object OB2 is sunk in the moving object OB1 is generated. Originally, as shown in FIG. 11B, it is natural that the dead leaf OB2 is located outside the moving body OB1.

  Therefore, in the image generation system of the present embodiment, when the dead leaf OB2 is present at a position where the dead leaf OB2 sinks into the moving body OB1, a process for correcting the dead leaf OB2 to an appropriate position is performed.

  First, a method for correcting the position of the second object based on the correction parameter will be described. As shown in FIG. 12, first, a correction area plane RP is set. The correction area plane RP is set based on the moving object OB1. For example, the position (X, Z) occupied by the moving object OB1 is set. Note that the correction parameters may be set in association with a plurality of grid points on the control area plane CP without setting the correction area plane RP. Note that the correction area plane RP is also set in the local coordinate system of the moving object OB1, similarly to the control area plane CP. This is because the correction parameter can be set regardless of the position of the moving body in the object space, and the correction calculation can be easily performed.

  Next, a correction parameter is set in association with each of a plurality of lattice points obtained by dividing the correction area surface RP into a lattice shape. Note that when the correction area surface RP is divided into a lattice, the control area surface CP may be divided in more detail than when the control area surface CP is divided into a lattice.

  FIG. 13 shows an example of a correction parameter table storing height parameters (an example of correction parameters) for correcting in the height direction (Y-axis direction).

  For example, the height parameter is set to the grid point on the correction area surface according to the shape of the moving object OB1. For example, the vicinity of (X, Z) = (1, 1) on the correction area surface is the roof portion of the moving object OB1, and when the height (Y value) of the roof portion is “2”, “2” is stored in the height parameter of (X, Z) = (1, 1). The vicinity of (X, Z) = (1, 3) on the correction area surface is the windshield portion of the moving object OB1, and the height (Y value) of the windshield portion is “1.5”. Stores “1.5” in the height parameter of (X, Z) = (1, 3). Further, the vicinity of (X, Z) = (1, 4) on the correction area surface is the bonnet portion of the moving object OB1, and when the height (Y value) of the bonnet portion is “1”, “1” is stored in the height parameter of (X, Z) = (1, 4).

  Then, a calculation for correcting the dead leaf OB2 is performed based on the position of the dead leaf OB2 and the correction parameter set in association with each lattice point on the correction area surface. Specifically, when correction is performed based on the height parameter of FIG. 13, the height (Y value) of the dead leaf OB2 is lower than the height parameter of the lattice point at the dead leaf OB2 position. Performs an operation of changing the height (Y value) of the dead leaves OB2 to the value of the height parameter.

  For example, as shown in FIG. 12, when the dead leaf OB2 is located at (X, Y, Z) = (1, 0.9, 4), for example, the lattice point (X, Z) = (1, 4 ) To get the height parameter. That is, in the example of FIG. 13, the height parameter “1” associated with the lattice point (X, Z) = (1, 4) is acquired. Since the dead leaf OB2 has a height (value of Y) of “0.9” and is lower than the height parameter “1”, the dead leaf OB2 is (X, A correction process is performed to raise the height to “1”, which is the correction parameter value of Z) = (1, 4).

  Further, when the dead leaf OB2 is at the position of (X, Y, Z) = (2, 3, 2), for example, the lattice point of the correction area plane RP of (X, Z) = (2, 2) Since the value of the height parameter associated with is “2”, the dead leaf OB2 is at a position higher than the correction parameter value (Y = 3), so the position of the dead leaf OB2 is not changed.

  Based on the above processing, in the image generation system of the present embodiment, the calculation of correction of dead leaves OB2 is performed. In this way, even when the moving body OB1 has a complex shape with irregularities, it is possible to prevent the generation of an unnatural image in which the dead leaves OB2 sink into the moving body OB1. In addition, according to the image generation system of the present embodiment, the position of the dead leaf OB2 is calculated by performing a vertex calculation between the vertex of the polygon constituting the dead leaf OB2 and the vertex of the polygon constituting the moving body OB1 strictly in a three-dimensional space. Compared with the method of performing the calculation for correcting the correction, the correction can be performed with a small amount of calculation.

  Note that the calculation for correcting the position of the second object is performed by interpolating a plurality of correction parameters and performing the correction calculation based on the interpolated values, as in the case of interpolating the movement / motion parameters described above. Also good. The correction may be performed by linearly interpolating correction parameters associated with a plurality of grid points around the point where the second object is projected on the correction area surface. For example, when acquiring a height parameter, a plurality of correction parameters may be used. The correction parameter having the largest value among the correction parameters associated with the lattice points may be acquired.

  Next, a calculation method for correcting the position of the second object using the volume will be described.

  FIG. 14 is a diagram illustrating an example in which correction is performed using a bounding box. When the moving body OB1 is an object characterized by a substantially rectangular parallelepiped shape such as a bus, for example, a rectangular parallelepiped bounding box BB can be used.

  And it is judged whether a part of dead leaf OB2 exists in bounding box BB. Specifically, it is determined whether a part of the dead leaf OB2 exists in the bounding box BB based on the vertex coordinates of the polygon constituting the dead leaf OB2 and the vertex coordinates of the polygon constituting the bounding box BB. .

  When a part of the dead leaf OB2 is present in the bounding box BB, the position of the dead leaf OB2 is corrected so that the position of the dead leaf OB2 is located outside the bounding box BB. For example, the Y value of the position coordinate of the dead leaf OB2 is changed so as to be located outside the bounding box BB.

  The calculation for correcting the position of the dead leaf OB2 may be performed before the calculation of the movement / motion of the dead leaf OB2 based on the movement / motion parameter in the control area. In addition, after calculating the movement / motion of the dead leaf OB2 based on the movement / motion parameter in the control area, it is preferable to perform the correction calculation based on the determined position of the dead leaf OB2. This is because it is possible to reliably prevent the image of the dead leaf OB2 from being embedded in the moving object OB1.

3. Processing of the present embodiment Next, a processing example for realizing the method of the present embodiment will be described in detail with reference to FIG.

  FIG. 15 is a flowchart for calculating dead leaf movement / motion and correction according to the method of the present embodiment.

  First, the position of the moving body is calculated (step S110). Next, a control area is set according to the position of the moving body (step S120). The control area is set in the local coordinate system of the moving body. Then, a movement / operation parameter and a correction parameter are set in association with a plurality of grid points obtained by dividing the control area plane set based on the control area into a grid pattern (step S130). That is, the movement / operation parameter and the correction parameter are set in association with a plurality of lattice points (X, Z) in the local coordinate system of the moving object obtained by dividing the control area surface.

  Next, the position of dead leaves in the local coordinate system of the moving object is calculated (step S140). The position of the dead leaf can be obtained by multiplying the position (coordinate) of the dead leaf in the world coordinate system by an inverse matrix of a determinant that converts the moving body from the local coordinate system to the world coordinate system. Then, based on the position of the dead leaf and the movement / motion parameter associated with each grid point on the control area surface, the movement / motion of the dead leaf is calculated (step S150).

  Next, it is determined whether or not the position of dead leaves is within the correction area (step S160). It may be determined whether at least a part of the dead leaves belong to the correction area. When it is determined that the position of the dead leaf is within the correction area (Yes in step S160), a calculation is performed based on the correction parameter so that the dead leaf is located outside the correction area (step S170). On the other hand, when it is not determined that the position of dead leaves is within the correction area (No in step S160), the process proceeds to the next step.

  Next, it is determined whether or not calculation has been performed for all dead leaves existing in the control area (step S180), and when movement and motion calculations have not been performed for all dead leaves existing in the control area ( The process of step S140 to step S180 is performed with respect to the dead leaf which has not performed the calculation of movement and operation | movement of step S180. On the other hand, if the movement / motion calculation has been performed for all dead leaves in the control area (Yes in step S180), the process ends.

4). Application Examples (1) Examples when a moving body collides with a wall According to the image generation system of the present embodiment, in addition to the above-described air flow control of dead leaves, for example, the moving body is a wall (for example, a brick). In the case of collision, an image expressing a state in which the wall collapses due to the collision can be generated.

  For example, when a moving object collides with a brick wall, a control area is set around the moving object, and the velocity vector (of the movement and operation parameters of the broken bricks broken when the moving object collides with the brick). One example) is set in advance in the movement / operation parameter table in association with each grid point on the control area surface. Then, based on the position of the brick fragment existing in the control area and the velocity vector associated with each lattice point on the control area surface, the movement / operation is calculated for the brick fragment. In this way, it is possible to easily calculate the movement / motion without performing the simulation calculation of the movement / motion of the brick fragments strictly.

  Further, based on the correction parameters set in association with the respective lattice points on the control area surface, it is possible to perform an operation for correcting the brick fragments that collapse around the moving body so as not to sink into the moving body. . In this way, it is possible to express a state in which broken brick fragments fall around the moving body with a simple calculation without strict judgment of collision between the brick fragments and the moving body.

(2) Example when the moving body passes under a branch According to the image generation system of the present embodiment, for example, it is possible to express an operation in which a tree branch swings as the moving body passes.

  For example, a control area is set around a moving object, and motion data (an example of movement / motion parameters) indicating movement of a tree branch in advance is associated with each grid point on the control area plane. It is set in advance in association with a point. If a tree branch exists in the control area, the calculation of the movement of the tree branch is performed based on the position of the tree branch and the motion data associated with each lattice point on the control area surface. Do. The motion data can be, for example, a series of operations in which the tree branch moves in the traveling direction of the moving body and then returns to the original position by the elastic force. In this way, when the moving body passes under the tree branch existing near the height of the moving body, it is possible to express the state of the tree branch shaking.

(3) Example in which movement / motion parameter is dynamically changed In the image generation system according to the present embodiment, the movement / motion parameter may be dynamically changed based on the movement speed and movement direction of the moving body. . This is because the movement and movement of dead leaves existing in the control area can be expressed according to the speed and moving direction of the moving body. Furthermore, the movement / motion parameters may be dynamically changed according to the weather in the object space, wind power, airflow generated by the movement of another moving body, and the like. In other words, depending on not only the airflow generated by the moving body but also the airflow generated based on other factors other than the moving body such as weather, wind, etc. The movement / motion calculation may be performed. In short, in this embodiment, the movement / motion parameters may be dynamically changed according to the game situation (moving speed, moving direction, weather, wind power, etc. of the moving body).

  Thus, when airflow control according to the game situation is expressed, only the movement / motion parameters stored in the movement / motion parameter table are dynamically changed without changing the correction parameters. In other words, the movement / motion parameters are set in the movement / motion parameter table, and the correction parameters are set in the correction parameter table, which are set in different tables. The air flow control of dead leaves can be expressed.

(4) Example when the moving body is deformed In the image generation system according to this embodiment, when the moving body is deformed, the correction parameters stored in the correction parameter table are changed based on the deformed moving body. May be. For example, when the moving body collides with a wall or the like and the shape of the moving body is deformed, it is desirable to correct the position of dead leaves to an appropriate position according to the shape of the moving body after deformation.

  In addition, when performing an operation for correcting the position of dead leaves using a volume, the correction operation is performed using a volume that includes the deformed moving body or a volume that represents the outline of the moving body after the change. It may be.

5. Hardware Configuration FIG. 16 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 (which may be a CD drive) accesses a DVD 982 (which 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.

  The present invention is not limited to that described in the above embodiment, and various modifications can be made. For example, terms cited as broad or synonymous terms in the description in the specification or drawings can be replaced with broad or synonymous terms in other descriptions in the specification or drawings. Further, the method of expressing the contact trace is not limited to that described in the present embodiment, and a method equivalent to these is also included in the scope of the present invention.

  In the image generation system of the present embodiment, for example, when the moving body is an airplane or a ship, it is desirable to set a control area according to the shape of the moving body and set the movement / operation parameters. . For example, when the moving body is a ship, the sea area around the ship is set as the control area, and the movement / motion calculation is performed so as to influence the ocean current on the objects existing in the control area. It may be.

  In the image generation system according to the present embodiment, the example in which the movement / motion parameter and the correction parameter are set based on the grid points that divide the control area plane into a grid has been described. However, the parameter indicating the behavior for the second object You may make it set.

  For example, if you want to express how a moving object (an example of a first object) burns and a dead leaf (an example of a second object) ignites, a plurality of lattice points that divide the control area surface into a lattice shape Corresponding temperature parameters may be set. In this way, for example, it is determined whether or not the dead leaf is ignited based on the position of the dead leaf and the temperature parameter associated with the lattice point (for example, based on the temperature parameter and a given threshold). However, if it is determined to ignite, an image as if dead leaves were ignited may be generated.

  The present invention can be applied to various games (racing game, fighting game, shooting game, robot battle game, sports game, competition game, role playing game, music playing game, dance game, etc.). The present invention also provides various image generation 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 personal computer, a multimedia terminal, a system board for generating game images, a mobile phone, Applicable to the system.

The example of a functional block diagram of the image generation system of this embodiment. 2A, 2B, and 2C are explanatory diagrams of a world coordinate system and a local coordinate system. 3A and 3B are explanatory diagrams of the control area. 4A and 4B are explanatory diagrams of the control area. 5A and 5B are explanatory diagrams of the control area. 6A and 6B are explanatory diagrams of the control area. FIGS. 7A and 7B are explanatory diagrams of a calculation method of movement / motion. 8A and 8B are explanatory diagrams of movement / operation parameters. 9A and 9B are explanatory diagrams of the control area. 10A and 10B are explanatory diagrams of interpolation. FIGS. 11A and 11B are explanatory diagrams of correction calculation methods. Explanatory drawing of the calculation method of correction | amendment. Explanatory drawing of a correction parameter. Explanatory drawing of the calculation method of correction | amendment. The flowchart of the process of this embodiment. Hardware configuration example.

Explanation of symbols

OB1 first object, OB2 second object,
CA control area, CP control area surface, RP correction area surface,
100 processing unit, 110 object space setting unit, 112 movement / motion processing unit,
114 area setting section, 116 parameter setting section,
120 drawing units, 130 sound generation units,
160 operation unit, 170 storage unit, 172 main storage unit,
174 Drawing buffer, 176 Object data storage unit,
180 information storage medium, 190 display unit, 192 sound output unit,
194 portable information storage device, 196 communication unit,

Claims (8)

A program for generating an image that can be seen from a given viewpoint in an object space,
An object space setting unit for setting the first object and the second object in the object space;
A movement / motion processing unit for calculating at least one of movement and motion of the first object and the second object;
An area setting unit for setting a control area according to the position of the first object;
Based on the control area, a parameter setting unit that sets a movement / operation parameter and a correction parameter in association with each of a plurality of grid points that divide the control area surface into a grid,
The computer functions as a drawing unit that generates an image that can be seen from a given viewpoint in the object space,
The area setting unit
An area including at least a part of the periphery of the first object is set as the control area;
The movement / motion processing unit
Based on the position of the second object existing in the control area and the movement / motion parameter associated with each grid point of the control area surface, at least one of movement and motion of the second object is determined. Calculating and correcting the position of the second object based on the position of the second object and the correction parameter associated with each grid point of the control area surface. Program to do. In claim 1 ,
The movement / motion processing unit
A program for performing a calculation for correcting a position of the second object after calculating at least one of movement and movement of the second object. In claim 1 or 2 ,
The area setting unit
An area surrounding the first object and surrounded by a predetermined range in a direction perpendicular to the control area surface and the control area surface is set as the control area. In any one of Claims 1-3 ,
The area setting unit
A common control area is set for a plurality of types of the first objects;
The parameter setting unit
A program for setting a common movement / operation parameter in association with each of the plurality of grid points that divide the common control area surface into a grid for a plurality of types of the first objects. . In any one of Claims 1-4 ,
The movement / motion processing unit
Interpolating the movement / motion parameters set at each grid point based on the position of the second object, and calculating at least one of movement and motion of the second object based on the interpolated value. A featured program. In any one of Claims 1-5 ,
The object space setting unit
Setting the first object in the object space by converting the position of the first object in the local coordinate system of the first object to a position in a coordinate system defining an object space;
The area setting unit
Set the control area to the local coordinate system,
The parameter setting unit
A plurality of grid points that divide the control area surface into a grid are set in the local coordinate system,
The movement / motion processing unit
A program for converting the position of the second object set in the object space into the local coordinate system and calculating based on the converted position. An information storage medium readable by a computer, wherein the program according to any one of claims 1 to 6 is stored. An image generation system for generating an image that can be seen from a given viewpoint in an object space,
An object space setting unit for setting the first object and the second object in the object space;
A movement / motion processing unit for calculating at least one of movement and motion of the first object and the second object;
An area setting unit for setting a control area according to the position of the first object;
Based on the control area, a parameter setting unit that sets a movement / operation parameter and a correction parameter in association with each of a plurality of grid points that divide the control area surface into a grid,
A drawing unit that generates an image viewed from a given viewpoint in the object space;
Including
The area setting unit
An area including at least a part of the periphery of the first object is set as the control area;
The movement / motion processing unit
Based on the position of the second object existing in the control area and the movement / motion parameter associated with each grid point of the control area surface, at least one of movement and motion of the second object is determined. Calculating and correcting the position of the second object based on the position of the second object and the correction parameter associated with each grid point of the control area surface. Image generation system.