JP2009169471A - Program, information storage medium, and image generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a program capable of obtaining performance effects with a suitable speed sensing, regardless of the location and direction of a virtual camera, and to provide an information storage medium and an image generation system. <P>SOLUTION: There is disclosed the program for generating an image seen through a virtual camera in an object space, with the program allowing a computer to function as a storage unit which stores an effect object EO, such that a plurality of segments move in one direction on surfaces of a column or polygonal pole, as a movement control unit which controls movements of a moving body object MO disposed in the object space, as a virtual camera control unit which performs control to make the virtual camera VC follow up the movements of the moving body object MO, and an object space setting unit which arrange the effect object EO in the object space, based upon the position of the moving body object MO. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  Conventionally, an image generation system (game system) that generates an image viewed from a virtual camera (a given viewpoint) in an object space (virtual three-dimensional space) in which a plurality of polygons are set is known. It is very popular for experiencing so-called virtual reality.

As such an image generation system, one that performs processing for producing the speed of a virtual camera or the like is known (for example, Patent Document 1).
JP 2002-170131 A

  In addition, there is a so-called concentrated line effect drawing method that expresses a concentrated line from the edge of the screen toward a moving body in the center of the screen using a plurality of polygons in the screen coordinate system and produces an effect of creating a sense of speed. . However, since this drawing process assumes that the virtual camera is positioned behind the moving body, for example, when the virtual camera is positioned beside the moving body, or the virtual camera is facing the moving direction. In the absence of this, there was a problem that an unnatural feeling of speed was produced.

The present invention has been made in view of the problems as described above, and the object is as follows.
An object is to provide a program, an information storage medium, and an image generation system capable of realizing an effect of appropriate speed feeling regardless of the position and orientation of a virtual camera.

(1) The present invention is a program for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object in which a plurality of line segments move in one direction on the surface of a cylinder or a polygonal column;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
The computer is caused to function as an object space setting unit that arranges the effect object in an object space based on the position of the moving object.

  The present invention also relates to an image generation system including the above-described units. The present invention is also a computer-readable information storage medium, and relates to an information storage medium storing a program that causes a computer to function as each of the above-described units.

  According to the present invention, by arranging an effect object in which a plurality of line segments move in one direction on the surface of a cylinder or a polygonal column in the object space based on the position of the moving object, the position and orientation of the virtual camera are set. Regardless, it is possible to produce an appropriate sense of speed.

(2) In the program and information storage medium according to the present invention,
The computer may further function as an effect control unit that increases or decreases the number of line segments of the effect object based on the speed of the moving object.

  According to the present invention, it is possible to produce an effect that increases the sense of speed according to the speed of the moving object.

(3) The present invention is a program for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object composed of a plurality of particles generated from a circle and moving in one direction;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
The computer is caused to function as an object space setting unit that arranges the effect object in an object space based on the position of the moving object.

  The present invention also relates to an image generation system including the above-described units. The present invention is also a computer-readable information storage medium, and relates to an information storage medium storing a program that causes a computer to function as each of the above-described units.

  According to the present invention, an effect object composed of a plurality of particles generated from a circle and moving in one direction is arranged in the object space based on the position of the moving object, so that regardless of the position and orientation of the virtual camera. An appropriate speed feeling can be produced.

(4) In the program and information storage medium according to the present invention,
The computer may further function as an effect control unit that increases or decreases the number of occurrences of the effect object based on the speed of the moving object.

  According to the present invention, it is possible to produce an effect that increases the sense of speed according to the speed of the moving object.

(5) In the program and information storage medium according to the present invention,
The object space setting unit
The effect object is arranged so that the effect object includes the moving object.

  According to the present invention, it is possible to produce an appropriate sense of speed regardless of the position and orientation of the virtual camera.

(6) In the program and information storage medium according to the present invention,
The movement control unit
Control to move the moving object along the course,
The object space setting unit
The effect object is arranged based on at least one of a position of the moving object and a shape of a course.

  According to the present invention, it is possible to arrange the effect object at the position and orientation corresponding to the position of the moving object moving along the course and the course shape, and it is possible to produce an appropriate sense of speed.

(7) In the program and information storage medium according to the present invention,
The object space setting unit
A gazing point of the virtual camera is obtained based on the position of the moving object and a path set along a course, and the effect object is arranged based on the obtained gazing point.

(8) In the program and information storage medium according to the present invention,
The virtual camera control unit
The virtual camera is controlled to move around the moving object based on operation data from an operation unit.

  According to the present invention, even if the virtual camera moves around the moving object while following the movement of the moving object, it is possible to produce an appropriate sense of speed.

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

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

  The operation unit 160 is for a player to input operation data of an object (player character, moving object), and its function can be realized by a lever, a button, a steering, a microphone, a touch panel type display, or a casing.

  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 object data storage unit 176 stores object data of objects. For example, effect object data (particles, polygons) is stored.

  Here, the effect object is an object in which a plurality of line segments move in one direction on the surface of a cylinder or a polygonal column. In this embodiment, the effect object is composed of a plurality of particles that are generated from a circle and move in one direction.

  Note that the operation unit 160 may be one that can input input data (operation data) from a player by an input device that includes an acceleration sensor, an imaging unit, or a gyro sensor that detects angular velocity. For example, an acceleration sensor provided in an input device detects acceleration in three axes (X axis, Y axis, and Z axis). That is, the acceleration sensor can detect acceleration in the vertical direction, the horizontal direction, and the front-rear direction. The acceleration sensor detects acceleration every 5 msec. Further, the acceleration sensor may detect a uniaxial, biaxial, or six-axis acceleration. The acceleration detected from the acceleration sensor is transmitted to the game device (main device) by the communication unit of the input device.

  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. The information storage medium 180 can store 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 communication unit 196 performs various controls for communicating with the outside (for example, another image generation system), and the function is realized by various processors or hardware such as a communication ASIC, a program, or the like. it can.

  Note that a program or data for causing a computer to function as each unit of the present embodiment stored in the information storage medium or storage unit of the server is received via the network, and the received program or data is received by the information storage medium 180. Or may be stored in the storage unit 170. The case where the program or data is received and the image generation system is made to function is also 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, the game process includes a process for starting a game when a game start condition is satisfied, a process for advancing the game, an object such as a character or a map, a process for placing an effect object, a process for displaying an object, a game result There is a process for calculating the game or a process for ending the game when the game end condition is satisfied.

  The processing unit 100 performs various processes using the main storage unit 172 in the storage unit 170 as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, 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, an effect control 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 is an object composed of various objects (polygons, free-form surfaces, subdivision surfaces, etc.) representing display objects such as characters, buildings, stadiums, cars, trees, pillars, walls, and maps (terrain). ) Is set in the object space. For example, the position and rotation angle (synonymous with the direction and direction of the object in the world coordinate system, for example, rotation when rotating clockwise when viewed from the positive direction of each axis of the X, Y, and Z axes in the world coordinate system. The angle is determined, and the object is arranged at the position (X, Y, Z) at the rotation angle (rotation angle about the X, Y, Z axis).

  In particular, the object space setting unit 110 of the present embodiment arranges the effect object stored in the object data storage unit 176 in the object space based on the position of the moving object.

  The object space setting unit 110 may arrange the effect object so that the effect object includes the moving object.

  The object space setting unit 110 may arrange the effect object based on at least one of the position of the moving object and the shape of the course.

  Further, the object space setting unit 110 may obtain a gazing point of the virtual camera based on the position of the moving object and a path set along the course, and may arrange the effect object based on the obtained gazing point.

  The movement / motion processing unit 112 (movement control unit) performs a movement / motion calculation (movement / motion simulation) of an object (character, moving object, etc.). In other words, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), a physical law, or the like, the object is moved in the object space or the object is moved ( (Motion, animation). 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.

  Further, the movement / motion processing unit 112 may perform control for moving the moving object along the course.

  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, the position (X, Y, Z) or rotation angle of the virtual camera in the world coordinate system (for example, the rotation angle when rotating in the clockwise direction when viewed from the positive direction of each axis of the X, Y, and Z axes). Process to control. In short, processing for controlling the viewpoint position, the line-of-sight direction, and the angle of view is performed.

  In particular, the virtual camera control unit 114 of the present embodiment performs control for causing the virtual camera to follow the movement of the moving object. That is, in order to shoot an object (for example, a character or a moving object) from behind using a virtual camera, the virtual camera position or rotation angle (virtual camera orientation) is set so that the virtual camera follows changes in the position or rotation of the object. ) To control. In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112.

  Further, the virtual camera control unit 114 may control the virtual camera to move around the moving object based on operation data from the operation unit. 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 control process is performed for each virtual camera.

  The effect control unit 116 increases or decreases the number of line segments of the effect object based on the speed of the moving object obtained by the movement / motion processing unit 112. That is, based on the speed of the moving object, control is performed to increase or decrease the number of occurrences of the effect object.

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

  In the vertex processing, according to the vertex processing program (vertex shader program, first shader program), vertex movement processing, coordinate transformation, for example, world coordinate transformation, visual field transformation (camera coordinate transformation), clipping processing, perspective transformation (projection transformation) ), Geometry processing such as viewport conversion is performed, and based on the processing result, the vertex data given to the vertex group constituting the object is changed (updated or adjusted).

  Then, rasterization (scan conversion) is performed based on the vertex data after the vertex processing, and the surface of the polygon (primitive) is associated with the pixel. Subsequent to rasterization, pixel processing (shading or fragment processing by a pixel shader) for drawing pixels (fragments forming a display screen) constituting an image is performed. In pixel processing, according to a pixel processing program (pixel shader program, second shader program), various processes such as texture reading (texture mapping), color data setting / change, translucent composition, anti-aliasing, etc. are performed, and an image is processed. The final drawing color of the constituent pixels is determined, and the drawing color of the perspective-transformed object is output (drawn) to the drawing buffer 174 (a buffer capable of storing 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) 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. In addition, when there are multiple virtual cameras, an effect object is associated with each virtual camera, and when generating an image that can be seen from a virtual camera, only the effect object associated with the virtual camera is drawn. However, the effect object associated with another camera may not be drawn.

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

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

  In the geometry processing, processing such as coordinate conversion, clipping processing, perspective projection conversion, or light source calculation is performed on the object. Then, object data (positional coordinates of object vertices, texture coordinates, color data (luminance data), normal vector, α value, etc.) after geometry processing (after perspective projection conversion) is stored in the object data storage unit 176. Is done.

  Texture mapping is a process for mapping a texture (texel value) stored in the texture storage unit 178 of the storage unit 170 to an object. Specifically, the texture (surface properties such as color (RGB) and α value) is read from the texture storage unit 178 of the storage unit 170 using the texture coordinates set (given) at the vertex of the object. Then, a texture that is a two-dimensional image is mapped to an object. In this case, processing for associating pixels with texels, bilinear interpolation or the like is performed as texel interpolation.

  As the hidden surface removal processing, hidden surface removal processing by a Z buffer method (depth comparison method, Z test) using a Z buffer 179 (depth buffer) in which a Z value (depth information) of a drawing pixel is stored may be performed. it can. That is, when drawing pixels corresponding to the primitive of the object are drawn, the Z value stored in the Z buffer 179 is referred to. Then, the Z value of the referenced Z buffer 179 is compared with the Z value at the drawing pixel of the primitive, and the Z value at the drawing pixel is the front side when viewed from the virtual camera (for example, a small Z value). If it is, the drawing process of the drawing pixel is performed and the Z value of the Z buffer 179 is updated to a new Z value.

  In addition, you may control so that the drawing pixel of an effect object (the particle and polygon which comprise an effect object) is not made into the object of Z test. That is, the drawing pixel of the effect object may be drawn without fail. Further, when drawing the effect object, the hidden surface removal process by the Z test may be performed with reference to only the Z value of the area where the moving object is drawn. That is, the drawing pixel of the effect object may be necessarily drawn in an area other than the area where the moving object is drawn.

  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).

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

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

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

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

2-1. Outline FIG. 2 is an example of a game image of the present embodiment.

  In the present embodiment, a game in which a moving object MO (a racehorse object that is a game character) runs along a course by an operation input from an operation unit is performed, and an object space including the moving object MO is viewed from a virtual camera. A viewed image is generated and displayed as a game image GI.

  In the present embodiment, the virtual camera is moved following the moving object MO, and as shown in FIG. 2, a plurality of moving images are moved while leaving an afterimage from the back side of the screen (forward in the traveling direction) toward the front side of the screen. By drawing particles PT (line particles, rectangular particles, moving line segments), the moving body MO and the virtual camera are sensed of speed. In the present embodiment, control is performed so as to increase or decrease the number of particles PT to be drawn according to the speed of the moving object MO.

2-2. Effect Object FIGS. 3 and 4 are diagrams for explaining an example of the effect object of the present embodiment. FIG. 3 is a perspective view of the effect object of the present embodiment.

  The effect object EO shown in FIG. 3 is defined in the effect coordinate system, and a circle having a radius r on the XY plane centered on the origin 0 of the effect coordinate system is defined as a particle emitter PE (particle generator). And a plurality of particles PT that move while leaving an afterimage at a predetermined speed in the + Z-axis direction of the effect coordinate system. That is, it can be said that the effect object EO shown in FIG. 3 is an effect object in which a plurality of line segments move in one direction on the surface of a virtual cylinder having a radius r. The shape of the particle emitter PE may be a polygon. In this case, an effect object in which a plurality of line segments move in one direction on the surface of the virtual polygonal column.

  FIG. 4 is a diagram for explaining an example of an effect parameter table storing effect parameters for defining the effect object EO shown in FIG.

  In the effect parameter table 200 shown in FIG. 4, the generation shape 210 and the generation frequency 220 are stored as parameters for defining the particle emitter PE, and the life 230, the moving speed 240, the shape 250, the parameters for defining each particle PT to be generated are stored. A color 260 and a blend type 270 are stored. Based on the effect parameter table 200 shown in FIG. 4, it is possible to define an effect object EO that generates 70 rectangular particles per second from a circle with a radius of 5 m, moving at 60 m / second while leaving an afterimage and disappearing in 1 second. Each rectangular particle disappears at a position of 60 m from the generation point due to the life 230 (1 second) and the moving speed 240 (60 m / second), but a semi-transparent time is set immediately before and after the generation. Therefore, the visible length (the length of the visible rectangular particle from the occurrence to the disappearance) is about 50 m.

2-3. Arrangement of Effect Objects Next, a method for arranging effect objects according to the present embodiment will be described with reference to FIGS. FIG. 5 is a diagram for explaining the movement of the moving object and the virtual camera of the present embodiment.

  In the present embodiment, the moving object MO moves at a predetermined speed in a direction along the path CP set in the center of the course CS. In the example shown in FIG. 5, the moving object MO is moving on the path CP. However, when the player inputs a command for moving the moving object MO to the right, the moving direction MD of the moving object MO is changed. When the player inputs a command to move the mobile object MO to the left by rotating the mobile object MO to the right of the course CS by rotating it to the right by a predetermined angle for a predetermined period, The moving direction MD is rotated to the left by a predetermined angle for a predetermined period, and control is performed to bring the moving object MO to the left side of the course CS. The moving object MO moved to the right or left side of the course CS has a predetermined speed in a direction parallel to the path CP (with a certain distance from the path CP) until a command for moving to the right or left is input again. Move with.

  When a command for accelerating the moving object is input by the player, control is performed to accelerate the moving object MO by applying a predetermined acceleration to the moving object MO for a predetermined period. By controlling the movement of the moving object MO in this way, the player can run the moving object MO in the course CS with a simple operation. For example, the moving object may run backward on the course CS. Can be prevented.

  The virtual camera VC is located behind the moving object MO in the traveling direction and moves following the movement of the moving object MO. The position on the path CP that is a predetermined distance (30 m) away from the position MP1 on the path CP closest to the position of the moving object MO (the same position as the moving object MO in the example of FIG. 5) is the note of the virtual camera VC. The viewpoint GP is a direction in which the virtual camera VC and the gazing point GP are connected to each other, which is the camera direction VD of the virtual camera VC. By determining the orientation of the virtual camera VC in this way, the virtual camera VC can be directed in a direction in which the moving object MO will move in the future, and an appropriate game image corresponding to the course shape can be generated. .

  FIG. 6 is a diagram for explaining the arrangement of the effect objects of the present embodiment.

  The position of the effect object EO of the present embodiment is determined based on the current position of the moving object MO. The effect object EO is arranged so as to include the moving object MO. That is, as shown in FIG. 6, the effect object EO is arranged so that the moving object MO is positioned on the Z axis of the effect object EO. In the example of FIG. 6, when the length of the effect object EO in the Z-axis direction is 50 m, the moving object MO is arranged at a position on the Z-axis that is 35 m from the origin of the Z-axis.

  In the example shown in FIG. 6, the direction of the effect object EO is determined based on the shape of the course CS. That is, the path CP at the position MP1 on the path CP closest to the position of the moving object MO is the course direction CD, and the course direction CD and the effect object EO are arranged so as to be parallel to each other.

  Also, as shown in FIG. 3, the plurality of particles PT are defined so as to move in the + Z-axis direction of the effect object EO. Therefore, as shown in FIG. As shown in FIG. 2, in the game image, a plurality of particles PT moving from the back side of the screen toward the front side of the screen can be expressed. That is, it is possible to represent a plurality of particles PT that move in a direction almost opposite to the traveling direction of the moving object MO.

  In the example shown in FIG. 6, the orientation of the effect object EO is determined so that the course orientation CD and the Z axis of the effect object EO are parallel to each other. However, in this case, the orientation of the effect object EO (course orientation CD) Since the deviation from the camera-facing VD is large, there is a possibility that it will be a sense of speed with a sense of discomfort. Therefore, as shown in FIG. 7, the orientation of the effect object EO may be matched with the camera orientation VD.

  In the example shown in FIG. 7, the direction of the effect object EO is determined based on the camera direction VD connecting the virtual camera VC and the gazing point GP. That is, the effect object EO is arranged so that the camera direction VD and the Z axis of the effect object EO are parallel, and the + Z axis direction of the effect object EO is opposite to the camera direction VD.

  As shown in FIG. 8, even when the moving object MO is not located on the path CP in the center of the course CS, a predetermined distance from the position MP1 on the path CP closest to the position of the moving object MO. The position on the separated path CP is the gazing point GP of the virtual camera VC, the direction connecting the virtual camera VC and the gazing point GP is the camera direction VD, and the effect object EO is arranged in accordance with the camera direction VD. .

  Thus, by aligning the direction of the effect object EO not to the course direction CD but to the camera direction VD, a plurality of particles are directed from the direction in which the moving object MO will move in the future toward the front of the screen (the virtual camera side). A moving game image can be generated, and a suitable sense of speed can be produced according to the current position and course shape of the moving object MO. That is, as shown in FIG. 7, when the moving object MO is approaching the right curve, a game image in which a plurality of particles fly from the right side of the moving direction of the moving object MO is generated, and the moving object MO is moved to the left. When the curve is approaching, a game image in which a plurality of particles fly from the left side in the moving direction of the moving object MO is generated.

2-4. Control of Virtual Camera FIG. 9 is a diagram for describing control of the virtual camera of the present embodiment.

  In the present embodiment, the virtual camera VC moves following the movement of the normal moving object MO and is controlled so as to face the gazing point GP on the path CP in the center of the course CS. However, the virtual camera VC is controlled by the player. When a command to change the direction is input, as shown in FIG. 9, control is performed to move the virtual camera VC so as to draw an arc around the moving object MO. At this time, the virtual camera VC moves in a predetermined movement range MA according to the input operation data, with the direction facing the moving object MO as the camera direction VDa (moving camera direction). By moving the virtual camera VC to the side surface of the moving object MO, the player can grasp the surrounding situation (for example, the positional relationship with other moving objects).

  As shown in FIG. 9, when the virtual camera VC is moved to the side surface of the moving object MO, the gazing point GP on the path CP is out of the field of view of the virtual camera VC, and thus is obtained from the gazing point GP. It is not appropriate to arrange the effect object EO in accordance with the camera orientation VD (automatic camera orientation). Therefore, in this embodiment, in such a case, the orientation of the effect object EO is determined in consideration of the course orientation CD.

  Specifically, the inner product of the automatic camera direction VD and the moving camera direction VDa is taken as f, and a combined vector SV obtained by combining the automatic camera direction VD and the course direction CD using the inner product f is obtained by the following equation.

SV = (CD × (1−f)) + (VD × f) (1)
Then, the effect object EO is arranged in accordance with the obtained composite vector SV. That is, the effect object EO is arranged so that the composite vector SV and the Z axis of the effect object EO are parallel.

  The direction of the effect object EO is closer to the automatic camera direction VD as the angle θ between the automatic camera direction VD and the moving camera direction VDa is smaller, and closer to the course direction CD as the angle θ is larger. As shown in FIG. 10, since the inner product f becomes 0 when the angle θ formed by the automatic camera direction VD and the moving camera direction VDa is 90 °, the combined vector SV becomes equal to the course direction CD from the equation (1). The effect object EO is arranged in accordance with the course-oriented CD. When the angle θ exceeds 90 ° (when the virtual camera VC is moved in front of the moving object MO), the inner product f is 0 or less, but in this case, the inner product f is set to 0 and the combined vector SV is set to 0. Ask.

  FIG. 11 is an example of a game image generated when the virtual camera VC is moved to the left side surface of the moving object MO as shown in FIGS. 9 and 10.

  In the game image GI shown in FIG. 11, a plurality of particles PT move from the left side of the screen (front of the moving object MO in the traveling direction) toward the right side of the screen while leaving an afterimage. Thereby, it is possible to produce a sense of speed of the moving object MO that moves from the right side of the screen to the left side of the screen.

  As described above, according to the present embodiment, the virtual camera VC is arranged by arranging the effect object EO composed of the plurality of particles PT generated from the circle and moving in one direction in the object space based on the position of the moving object MO. Even if it is located behind the moving object MO (see FIG. 2) or even if it is located on the side surface of the moving object MO (see FIG. 11), it is always possible to produce an appropriate sense of speed. Can do.

3. Processing of this Embodiment Next, an example of processing of this embodiment will be described using the flowchart of FIG.

  First, based on operation data and a program, the position and direction of the moving body object which moves along a course are calculated | required (step S10).

  Next, the position and direction (gaze point) of the virtual camera that follows the movement of the moving object are obtained based on the position of the moving object and the path information set in the course (step S12).

  Next, the number of generated particles of the effect object is obtained based on the speed of the moving object (step S14). For example, referring to the occurrence frequency parameter 220 stored in the effect parameter table 200 shown in FIG. 4, the parameter is multiplied by a coefficient (0.0 to 2.0) corresponding to the moving speed, and the particle per unit time. The number of occurrences is obtained, and more particles are generated as the speed of the moving object increases.

  Next, a process of placing the effect object defined in the effect coordinate system in the object space (world coordinate system) is performed (step S16). For example, the position of the effect object is obtained based on the position of the moving object, and the direction of the effect object is obtained based on the gazing point of the virtual camera.

  And the process which produces | generates the image seen from a virtual camera is performed (step S18). Note that processing may be performed so that the drawing pixels of the effect object are always drawn without performing the Z test determination. Thereby, even when the course is narrow or there are obstacles, it is possible to always draw an effect object for producing a sense of speed.

4). Modifications 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.

  For example, in the present embodiment, a case has been described in which an effect object in which a plurality of line segments move in one direction on the surface of a cylinder is configured by a plurality of particles that are generated from a circle and move in one direction. As described above, the effect object EO may be constituted by a cylindrical object, and the texture TX in which a plurality of line segments LN parallel to each other is represented on the side surface of the object may be mapped. The plurality of line segments LN may be moved in the + Z-axis direction by changing the texture coordinates and scrolling the texture TX in the + Z-axis direction of the object. A plurality of textures having different numbers of line segments LN may be prepared, and the texture to be mapped may be changed according to the speed of the moving object. In the example shown in FIG. 13, a polygonal column object may be used instead of the columnar object.

The example of a functional block diagram of the image generation system of this embodiment. An example of the game image of this embodiment. The perspective view of the effect object of this embodiment. An example of the effect parameter table of this embodiment. The figure for demonstrating the motion of the mobile body object of this embodiment, and a virtual camera. The figure for demonstrating arrangement | positioning of the effect object of this embodiment. The figure for demonstrating arrangement | positioning of the effect object of this embodiment. The figure for demonstrating arrangement | positioning of the effect object of this embodiment. The figure for demonstrating control of the virtual camera of this embodiment. The figure for demonstrating control of the virtual camera of this embodiment. An example of the game image of this embodiment. The flowchart figure which shows the flow of the process of this embodiment. The modification of the effect object of this embodiment.

Explanation of symbols

100 processing unit, 110 object space setting unit, 112 movement / motion processing unit, 114 virtual camera control unit, 116 effect control unit, 120 drawing unit, 130 sound generation unit, 160 operation unit, 170 storage unit, 180 information storage medium, 190 Display unit, 192 Sound output unit, 196 Communication unit

Claims (11)

A program for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object in which a plurality of line segments move in one direction on the surface of a cylinder or a polygonal column;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
A program that causes a computer to function as an object space setting unit that arranges the effect object in an object space based on the position of the moving object. In claim 1,
A program that further causes a computer to function as an effect control unit that increases or decreases the number of line segments of the effect object based on the speed of the moving object. A program for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object composed of a plurality of particles generated from a circle and moving in one direction;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
A program that causes a computer to function as an object space setting unit that arranges the effect object in an object space based on the position of the moving object. In claim 3,
A program that further causes a computer to function as an effect control unit that increases or decreases the number of occurrences of partying of the effect object based on the speed of the moving object. In any one of Claims 1 thru | or 4,
The object space setting unit
A program characterized in that the effect object is arranged so that the effect object includes the moving object. In any one of Claims 1 thru | or 5,
The movement control unit
Control to move the moving object along the course,
The object space setting unit
A program characterized in that the effect object is arranged based on at least one of a position of the moving object and a shape of a course. In claim 6,
The object space setting unit
A program characterized in that a gazing point of the virtual camera is obtained based on the position of the moving object and a path set along a course, and the effect object is arranged based on the obtained gazing point. In any one of Claims 1 thru | or 7,
The virtual camera control unit
A program for controlling the virtual camera to move around the moving object based on operation data from an operation unit.   A computer-readable information storage medium, wherein the program according to any one of claims 1 to 8 is stored. An image generation system for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object in which a plurality of line segments move in one direction on the surface of a cylinder or a polygonal column;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
An image generation system comprising: an object space setting unit that arranges the effect object in an object space based on the position of the moving object. An image generation system for generating an image visible from a virtual camera in an object space,
A storage unit for storing an effect object composed of a plurality of particles generated from a circle and moving in one direction;
A movement control unit for controlling movement of a moving object placed in the object space;
A virtual camera control unit for controlling the virtual camera to follow the movement of the moving object;
An image generation system comprising: an object space setting unit that arranges the effect object in an object space based on the position of the moving object.

Images