JP2007164736A - Image generation system, program and information storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively express view of a rainbow, which is changing according to the various factors of a natural field with a small processing load. <P>SOLUTION: This program for generating an image to be viewed from a virtual camera in an object space makes a computer function as an optical effect expression object setting part 116 for changing at least one of the shape, size and appearing position of an optical effect expression object based on the light source position and the optical vector direction and a plotting part 120 for plotting an image in which the object space where the optical effect expression object has been arranged from a virtual camera. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  Conventionally, an image generation system (game system) that generates an image that can be viewed from a virtual camera (a given viewpoint) in an object space (virtual three-dimensional space) in which an object such as a character is set is known. It is popular as a place to experience so-called virtual reality.

Now, in such a game system, it is an important technical problem to generate a more realistic image in order to improve the player's virtual reality.
JP-A-11-306391

  For example, a rainbow is generated when the light is reflected by water droplets in the air, due to the difference in the refractive index of light depending on the color (wavelength of light), and in the natural world such as the angle of light from the light source and the air condition. The appearance changes depending on various factors.

  However, when expressing a rainbow in the game space, the same rainbow is always displayed because it is usually realized by a simple configuration in which a rainbow object prepared in advance is arranged and drawn. Therefore, it is monotonous as a natural depiction, and it is unsatisfactory for a game with a strong element of enjoying natural depiction.

  However, rigorously simulating the changing appearance of the rainbow, which is caused by various factors in the natural world, adds to the computation, and processing is difficult for game devices that require real-time image generation with limited hardware resources. There was a problem that it was difficult.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to effectively represent the appearance of the rainbow that changes due to various factors in the natural world with a small amount of processing. An image generation system, a program, and an information storage medium are provided.

(1) The present invention
An image generation device for generating an image visible from a virtual camera in an object space,
A light effect expression object setting unit that changes at least one of the shape, size, and appearance position of the light effect expression object based on the light source position or the direction of the light vector;
A drawing unit that draws an image of an object space in which a light effect expression object is arranged viewed from a virtual camera;
Related to an image generation system.

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

  The light effect expression object may be, for example, a rainbow, an object for expressing various phenomena caused by light reflection, refraction, light emission, or the like, or an aurora, a cloud, a mirage, or the like.

  In addition, the case of expressing a light phenomenon that does not exist in the real world is also within the scope of the present invention.

  The ray vector may be a ray vector of a parallel light source. Further, when the point light source is set at a location far away from the object space, the ray vectors are almost parallel, and therefore the ray vector of the point light source may be used.

  The light effect expression object setting information including at least one of the shape, size, and appearance position of the light effect expression object is determined based on the light source position or the direction of the light vector. The correspondence between at least one of the incident angle of the vector, the angle formed by the horizontal circle, the reflection angle, etc.) and the shape, size, and appearance position of the light effect expression object is set in advance as table data or the like. A configuration may be used in which at least one of the shape, size, and appearance position of the light effect expression object is determined based on this.

  Further, a function for obtaining at least one of the shape, size, and appearance position of the light effect expression object is set using the light source position or the direction of the light vector as a variable, and the shape, size, and It may be configured to determine at least one of the appearance positions.

  The shape and size of the light effect expression object are set based on the arc when a predetermined vector V is set at the viewpoint position based on the light source position or the direction of the light vector, and an arc is drawn on the predetermined virtual projection plane with the predetermined vector V. Alternatively, an algorithm for determining at least one of the height and the appearance position may be set, and at least one of the shape, size, and appearance position of the light effect expression object may be determined based on the algorithm.

  Since the light effect expression object is caused by the reflection of sunlight into the water droplets in the air, the position and size of the light effect expression object differ depending on the position of the sun.

  According to the present invention, it is possible to generate an image of a light effect expression object in which at least one of the shape, size, and appearance position differs based on the light source position and the direction of the light vector. Therefore, an effective light effect expression can be expressed with a small calculation load without strictly performing a simulation calculation on the appearance of a light effect expression such as a rainbow that changes depending on the position of the sun.

(2) In the image generation system, program, and information storage medium according to the present invention,
It includes a light source control unit that changes a light source position or a direction of a light vector according to a change in game time.

  Model the situation where the position of the sun changes according to the time of the real world (for example, climbing from the morning east to the south in the daytime and sinking to the west in the evening), and the light source position or the direction of the light vector according to the game time It may be changed.

  According to the present invention, if the game time at which the light effect expression object appears is different, an image of the light effect expression object having at least one different shape, size, and appearance position can be generated.

  Accordingly, since an image of at least one different light effect expression object having a different shape, size, and appearance position is generated depending on the game time, it is possible to express a rainbow with a depth that is not monotonous and the flow of time in the game space Can also feel.

(3) In the image generation system, the program, and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
Set a virtual projection plane at a point away from the viewpoint position by a predetermined distance in the direction opposite to the light source,
The first direction vector V1 is set by shifting by a predetermined angle with respect to the direction of the ray vector, the second direction vector V2 is set by shifting by a slight angle with respect to the first direction vector V1, and the first direction The vector V1 and the second direction vector V2 are extended toward the virtual projection plane starting from the viewpoint position, and based on the intersection of the first direction vector V1 and the extension line of the second direction vector V2 and the virtual projection plane. At least one of a shape, a size, and an appearance position of the light effect expression object is set.

  Since the virtual projection plane may be set far from the viewpoint, the predetermined distance can be appropriately set as long as it is far from the viewpoint.

  The first direction vector V1 and the second direction vector V2 are vectors shifted by a minute angle. The minute angle can be set so as to reflect the difference in refractive index depending on the wavelength of light. For example, it may be set based on an angle formed by red reflected light and purple reflected light.

  In this way, since at least one of the shape, size, and appearance position of the light effect expression object can be determined based on the direction of the light vector, a realistic rainbow image can be generated.

(4) In the image generation system, the program, and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
Set a virtual projection plane at a point away from the viewpoint position by a predetermined distance in the direction opposite to the light source,
A direction vector V obtained by shifting by a predetermined angle with respect to the direction of the ray vector is extended from the viewpoint position to the virtual projection plane, and a first intersection that is an intersection of the extension line of the direction vector V and the virtual projection plane. And extending a ray vector from the viewpoint position toward the virtual projection plane, obtaining a second intersection that is an intersection of the extension line of the ray vector and the virtual projection plane, and producing a light effect based on the first intersection and the second intersection At least one of the shape, size, and appearance position of the expression object is set.

  Since the virtual projection plane may be set far from the viewpoint, the predetermined distance can be appropriately set as long as it is far from the viewpoint.

  Setting at least one of the shape, size, and appearance position of the light effect expression object based on the first intersection and the second intersection means, for example, that the radius of the circle is set based on the first intersection and the second intersection. The shape of the light effect expression object may be set based on the specified circle having the specified radius.

  Further, the position of the light effect expression object may be determined based on the second intersection point (for example, the setting position of the light effect expression object is set at the second intersection point).

  According to the present invention, at least one of the shape, size, and appearance position of the light effect expression object can be changed according to the direction of the light vector.

  For example, at least one of the shape, size, and appearance position of the light effect expression object can be determined based on a circle having a larger radius as the direction of the light vector is closer to the vertical or the position of the light source is higher.

(5) In the image generation system, the program, and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
An annular object is set as the light effect expression object.

  The upper half of the annular light effect expression object may be used.

  A rainbow image may be generated by mapping a rainbow texture (for example, a seven-color light band pattern) of the light effect expression object pattern to the annular light effect expression object.

(6) In the image generation system, the program, and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
The light effect expression object is set to be arranged for a predetermined time at a given timing.

(7) In the image generation system, the program, and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
At least one of a setting process for causing the light effect expression object to fade-in and displaying the light effect expression object in a predetermined period from the start of arrangement, and a setting process for causing the light effect expression object to fade out and display in a predetermined period before the arrangement ends. It is characterized by performing.

  The fade-in process changes the display state of the light effect expression object over time from the state where the light effect expression object is not visible (transparent state) to the state where it gradually becomes dark (transparency gradually decreases). It is a process to change.

  The fade-out process changes the display state of the light effect expression object over time from a state where the light effect expression object is clearly visible to a state where the light effect expression object gradually becomes thinner (transparency increases gradually) and is not visible (transparency is 0). It is processing.

  The display control for fading in the light effect expression object image and the display control for fading out the light effect expression object image can be done by changing the alpha value of the light effect expression object and adding the light effect expression object semitransparent. It may be realized by drawing.

  For example, the reference value of the light effect expression object or the value set in the light effect expression object is α, the value at a certain game time is α ′, and the control parameter k corresponding to the elapsed time t from the start of the light effect expression object arrangement is set. Alternatively, α ′ satisfying α ′ = kα may be obtained.

  The α value may be set for each object, may be set for each vertex of the polygon, or may be set for each pixel.

  The above transparency control is realized by pixel processing performed by the rendering unit (hardware that enables polygon (primitive) rendering processing to be programmed by a shader program described in a shading language), so-called programmable shaders (vertex shaders and pixel shaders). May be.

  Moreover, you may implement | achieve by texture mapping. In this case, the texture color distribution and α value distribution (texel pattern) to be mapped to the light effect expression object may be dynamically changed in accordance with fade-in and fade-out.

  In this case, textures having different color distributions or α value distributions may be dynamically generated, or a plurality of textures having different color distributions or α value distributions are prepared in advance, and the textures to be used are dynamically generated. You may make it switch to. The texture color distribution may be changed in units of objects, or the texture color distribution may be changed in units of objects.

  According to the present invention, the appearance of a light effect expression object can be represented by an image, with the appearance of the light effect expression object appearing faint, gradually becoming clearer, and gradually fading and disappearing.

(8) In the image generation system, the program and the information storage medium according to the present invention,
The light effect expression object setting unit includes:
The display range control information for controlling the display range of the light effect expression object is set, and the light effect expression object is set so as not to be displayed for a portion that falls outside the display range based on the display range control information.

  As the display range control information, for example, a region to be a display range is defined, it is determined whether or not it belongs to the region to be the display range, and a portion not belonging to the region to be the display range of the light effect expression object is not displayed. May be.

  For example, assuming that a light effect expression object is set on the virtual projection plane, an area where the light effect expression object appears on the virtual plane may be set, or a non-display area where the light effect expression object does not appear is set. This is also within the scope of the present invention. The virtual projection plane can be set, for example, as a YX plane orthogonal to the Z axis in the starting point coordinate system.

  The light effect expression object display area may be defined by X and Y values on the virtual projection plane.

  The display / non-display area may be set at random, or may be set according to the atmospheric state (water vapor state) of the object space, for example.

  The display / non-display control may be, for example, a case where the object itself exists and only the part belonging to the display area of the object is displayed and the part belonging to the non-display area is not displayed. In this case, it may be controlled so that the non-display area is not displayed by increasing transparency (for example, α value).

  For the display area, the light effect expression object may be cut out, or the light effect expression object may be generated only in a portion corresponding to the display area.

  According to the present invention, it is possible to perform image representation of a light effect expression such as a rainbow that reflects various conditions such as atmospheric conditions.

  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 this embodiment may have a configuration in which some of the components (each unit) in FIG. 1 are omitted.

  The operation unit 160 is for a player to input operation data, and the function can be realized by a lever, a button, a steering, a microphone, a touch panel display, a housing, or the like.

  The storage unit 170 includes a drawing buffer 172, a Z buffer 174, and a texture storage unit 176, and serves as a work area for the processing unit 100, the communication unit 196, and the like, and its functions can be realized by a RAM or the like.

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

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

  The portable information storage device 194 stores player personal data, game save data, and the like. Examples of the portable information storage device 194 include a memory card and a portable game device.

  The communication unit 196 performs various controls for communicating with the outside (for example, a host device or other image generation system), and functions thereof are hardware such as various processors or a communication ASIC, It can be realized by a program.

  Note that a program (data) for causing a computer to function as each unit of this embodiment is distributed from the information storage medium of the host device (server) to the information storage medium 180 (storage unit 170) via the network and the communication unit 196. You may do it. Use of the information storage medium of such a host device (server) can also be included in the scope of the present invention.

  The processing unit 100 (processor) performs processing such as game processing, image generation processing, or sound generation processing based on operation data and programs from the operation unit 160. Here, as the game process, a process for starting a game when a game start condition is satisfied, a process for advancing the game, a process for placing an object such as a character or a map, a process for displaying an object, and a game result are calculated. There is a process or a process of ending a game when a game end condition is satisfied. The processing unit 100 performs various processes using the storage unit 170 as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs.

  The processing unit 100 includes an object space setting unit 110, a movement / motion processing unit 112, a virtual camera control unit 114, a light effect expression object setting unit 116, a light source control unit 118, a drawing unit 120, and a sound generation unit 130. Some of these may be omitted.

  The object space setting unit 110 is a variety of objects (objects composed of primitive surfaces such as polygons, free-form surfaces or subdivision surfaces) representing display objects such as characters, trees, cars, columns, walls, buildings, and maps (terrain). The process of setting the placement in the object space is performed. 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.

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

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

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

  The light effect expression object setting unit 116 performs a process of changing at least one of the shape, size, and appearance position of the light effect expression object based on the light source position or the direction of the light vector.

  The light effect expression object setting unit 116 sets a virtual projection plane at a point away from the viewpoint position by a predetermined distance in the opposite direction to the light source, and shifts the first direction by shifting the predetermined direction with respect to the direction of the light vector. A vector V1 is set, and a second direction vector V2 is set by shifting the first direction vector V1 by a slight angle, and the first direction vector V1 and the second direction vector V2 are used as the starting point for the virtual position. Extending toward the projection plane, at least one of the shape, size, and appearance position of the light effect expression object is determined based on the intersection of the first direction vector V1 and the extension line of the second direction vector V2 and the virtual projection plane. You may make it set.

  The light effect expression object setting unit 116 sets a virtual projection plane at a predetermined distance away from the viewpoint position in a direction opposite to the light source, and a direction obtained by shifting the virtual projection plane by a predetermined angle with respect to the direction of the light vector. The vector V is extended from the viewpoint position toward the virtual projection plane, the first intersection point of the extension line of the direction vector V and the virtual projection plane, and the ray vector is extended from the viewpoint position toward the virtual projection plane. A second intersection that is an intersection of the ray vector extension line and the virtual projection plane is obtained, and at least one of the shape, size, and appearance position of the light effect expression object is set based on the first intersection and the second intersection. You may do it.

  The light effect expression object setting unit 116 may set an annular object as the light effect expression object.

  The light effect expression object setting unit 116 may set the light effect expression object to be arranged for a predetermined time at a given timing.

  The light effect expression object setting unit 116 fades out the light effect expression object in a predetermined period before the arrangement ends, and a setting process for fading in and displaying the light effect expression object in a predetermined period from the start of the arrangement. You may make it perform at least 1 of the setting processing for displaying.

  The light effect expression object setting unit 116 sets display range control information for controlling the display range of the light effect expression object, and no light effect expression object is displayed for a portion that falls outside the display range based on the display range control information. You may make it set as follows.

  The light source control unit 118 performs a process of changing the light source position or the direction of the light vector according to the change of the game time.

  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.

  The drawing unit 120 draws an image obtained by viewing the object space in which the light effect expression object is arranged from the 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 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 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 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 an object is configured based on the processing result. Change (update, adjust) the vertex data given 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 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 main storage unit 172. The

  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.

  In particular, in the present embodiment, when drawing a light effect expression object, for example, a process of mapping a light effect expression texture for expressing a rainbow or the like may be performed. In this case, the texture color distribution (texel pattern) mapped to the light effect expression object may be dynamically changed. In this case, textures having different color distributions may be dynamically generated, or a plurality of textures having different color distributions may be prepared in advance and the texture to be used may be dynamically switched. The texture color distribution may be changed in units of objects, or the texture color distribution may be changed in units of objects.

  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.

RQ = (1−α) × R1 + α × R2 (1)
GQ = (1−α) × G1 + α × G2 (2)
BQ = (1−α) × B1 + α × B2 (3)
Taking the case where the synthesis process is addition α blending as an example, the color synthesis unit 126 performs the α synthesis process according to the following equation.

RQ = R1 + α × R2 (4)
GQ = G1 + α × G2 (5)
BQ = B1 + α × B2 (6)
Taking the case where the composition processing is α multiplication as an example, the color composition unit 126 performs the α composition processing according to the following equation.

RQ = α × R1 (7)
GQ = α × G1 (8)
BQ = α × B1 (9)
Taking the case where the synthesis process is addition of α power as an example, the color synthesis unit 126 performs the α synthesis process according to the following equation.

RQ = α × R1 + R2 (7)
GQ = α × G1 + G2 (8)
BQ = α × B1 + B2 (9)
Here, R1, G1, and B1 are R, G, and B components of the color (luminance) of an image (background image) that has already been drawn in the drawing buffer 172, and R2, G2, and B2 are in the drawing buffer 172. The R, G, and B components of the color of the object (primitive) to be drawn. RQ, GQ, and BQ are R, G, and B components of the color of an image obtained by α blending. The α value is information that can be stored in association with each pixel (texel, dot), for example, plus alpha information other than color information. The α value can be used as mask information, translucency (equivalent to transparency and opacity), bump information, and the like.

  The α 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. Rainbow Object Setting Control Hereinafter, a rainbow object setting process when a rainbow image is generated using a rainbow object which is an example of a light effect expression object will be described. FIG. 2 shows a first direction set based on a light vector. It is a figure for demonstrating the vector V1 and the 2nd direction vector V2.

  This figure is a view (YZ plane) of the object space viewed in the X-axis direction.

Here, 210 is a parallel light source, and LV is a light vector. When a parallel light source is used, the light vector LV in the object space has the same direction at any point 230 is a virtual projection plane virtually assumed in the object space. In the present embodiment, a rainbow image is generated on the assumption that a rainbow is reflected on the virtual projection plane. Since the rainbow can be opposite to the light source with respect to the viewpoint (the position of the virtual camera), the virtual projection plane 230 is perpendicular to the horizontal plane 260 at a point away from the viewpoint opposite to the virtual projection plane with respect to the viewpoint 250. Is set as a virtually placed surface.

  The first direction vector V1 is set by shifting it by a predetermined angle with respect to the direction of the light vector LV, and the second direction vector V2 is set by shifting by a minute angle with respect to the first direction vector V1.

  The first direction vector V1 is set by shifting by a predetermined angle θ with respect to the direction of the light vector, and the second direction vector V2 is set by shifting by a minute angle Δθ with respect to the first direction vector V1.

  FIG. 3 is a diagram for explaining a method of setting a rainbow object based on the first direction vector V1 and the second direction vector V2.

  The virtual projection plane 230 is set from the viewpoint position 250 in the opposite direction to the light source 210, and the first direction vector V1 and the second direction vector V2 are extended from the viewpoint position to the virtual projection plane 230, and the first The position and size of the rainbow object 300 are determined based on the extension lines of the direction vector V1 and the second direction vector V2 and the intersection points P1 and P2 of the virtual projection plane 230.

  FIG. 4 is a diagram for explaining a method for setting the shape of a ring object of a rainbow object.

  The virtual projection plane 230 is set in the direction opposite to the light source 210 from the viewpoint position 250.

   A direction vector V obtained by shifting by a predetermined angle with respect to the direction of the light vector LV is extended from the viewpoint position to the virtual projection plane, and a first intersection that is an intersection of the extension line of the direction vector V and the virtual projection plane. Find P.

  Further, a second intersection point Q which is an intersection point of the extension line of the ray vector extending from the viewpoint position 250 toward the virtual projection plane and the virtual projection plane is obtained.

  The intersection point Q may be set as the center of a circle of an annular object that is a light effect expression object.

  Then, based on the first intersection P and the second intersection Q, the radius r of the annular object that is the light effect expression object may be determined.

A circle with a radius r centering on Q may be set virtually, and a rainbow object may be set along the circumference 320 of the circle. For example, when determining the position of a rainbow object along a circle (in this case, the rainbow object is set so that the position of the circle and the position of the rainbow object overlap. The highest point of the rainbow object and the highest point of the circle overlap) The position of the rainbow object is determined), and the size of the rainbow object is determined according to the size of the circle (for example, the radius of the arc of the rainbow object is determined).

  FIG. 5 is a diagram for explaining the relationship between the light source position (light source height) and the size and position of the set rainbow object.

  For example, when there is a light source at 210-1, a first direction vector V1-1 and a second direction vector V2-1 are set for the light vector LV-1, and the first position vector 250-1 is set as the first point. The rainbow object 400-1 is set by intersections P1-1 and P2-1 with the virtual projection plane when the direction vector V1-1 and the second direction vector V2-1 are extended in the direction of the virtual projection plane. The

  For example, when the light source is 210-2, the first direction vector V1-2 and the second direction vector V2-2 are set with respect to the light vector LV-2, and the viewpoint position 250 is the starting point. The rainbow object 400-2 is set by intersections P1-2 and P2-2 with the virtual projection plane when the one direction vector V1-2 and the second direction vector V2-2 are extended in the direction of the virtual projection plane. Is done.

  In the present embodiment, the light source position or the direction of the light vector of the parallel light source is changed according to the change of the game time, so that a rainbow image with a different size and such position is generated reflecting the light source position and the direction of the light vector. .

  FIGS. 6A and 6B are diagrams for explaining the control of the display range of the rainbow object according to the present embodiment.

  In this embodiment, a rainbow object is set on the virtual projection plane. At this time, an area where the rainbow object appears can be set. The virtual projection plane can be set, for example, as a YX plane orthogonal to the Z axis in the viewpoint coordinate system.

  FIG. 6A shows a case where an area of X> a on the virtual projection plane is set as the display area of the rainbow object. In this case, 550-1 of the virtual projection plane is a display area, and 560-1 is a non-display area. In the rainbow object 510, the part 510-2 belonging to the display area is displayed, and the parts 510-1 and 510-3 belonging to the non-surface area are not displayed.

  FIG. 6B shows a case where an area of X> b and Y> c on the virtual projection plane is set as the display area of the rainbow object. In this case, the virtual projection plane 550-2 is a display area, and 560-2 is a non-display area. In the rainbow object 510, the part 510-2 'belonging to the display area is displayed, and the parts 510-1' and 510-3 'belonging to the non-surface area are not displayed.

  The display / non-display area may be set at random, or may be set according to the atmospheric state (water vapor state) of the object space, for example.

  The display / non-display control may be, for example, a case where the object itself exists and only the part belonging to the display area of the object is displayed and the part belonging to the non-display area is not displayed. In this case, it may be controlled so that the non-display area is not displayed by increasing transparency (for example, α value).

  As for the display area, a rainbow object may be cut out, or a rainbow object may be generated only in a portion corresponding to the display area.

  FIG. 7 is a diagram for explaining the rainbow fade-in / fade-out process of the present embodiment.

  In the present embodiment, the rainbow object is arranged for a predetermined time at a given timing. That is, a rainbow object is set from the time when the rainbow appears until it disappears (t0 to t3).

  For example, when a rainbow object appears at a given timing t0, a fade-in process is performed during a predetermined period (between t0 and t1) from the arrangement start t0 during the fade-in period 610.

  The fade-in process changes the display state of the rainbow object over time so that the rainbow object is gradually visible (transparent state) and gradually becomes darker (transparency becomes lower). It is a process to make.

  The rainbow object is clearly visible in the state of t1, and a predetermined period (t2 to t3) before the arrangement ends is a fade-out period 620, and a fade-out process is performed.

  The fade-out process is a process of changing the display state of the rainbow object over time so that the rainbow object is gradually thinned (increased in transparency) and invisible (transparency is 0). It is.

  FIG. 8 is a diagram showing the relationship between the elapsed time and the α value.

  The horizontal axis represents the elapsed time t from the appearance of the rainbow object, and the vertical axis represents the transparency information (α value) when the rainbow object is drawn with additive semi-transparency. In this embodiment, the rainbow object is set for a predetermined time from the appearance t0 of the rainbow object to the disappearance t3 of the rainbow object.

  When a rainbow object is drawn with additive semi-transparency, the rainbow object is transparent when the α value is 0, and the rainbow object is clearly visible when the α value is 1.

  When the rainbow object appears (time t0), the α value is set to 0, and thereafter the α value is gradually increased during the fade-in period 610, and the α value is controlled to 1 at the time t1.

  Then, control is performed so that the α value gradually decreases during the fade-out period 620 after t2, and the α value becomes 0 at the time t3.

  In this way, the rainbow object begins to gradually appear from the time point t0, becomes clearly visible at the time point t1, becomes thin again from the time point t3, and shows that the rainbow object becomes invisible at the time point t4. be able to.

  When the rainbow fade-in / fade-out is realized by changing the α value of the rainbow object and rendering the rainbow object semi-transparently, for example, the reference value or set value is α, and the elapsed time t from the appearance of the rainbow object Alternatively, α may be directly controlled based on the predetermined function f (t) = α based on the elapsed time t.

  Alternatively, the α value at the elapsed time t may be α ′, and a value of k that satisfies α ′ = kα with a predetermined function f ′ (t) = k may be obtained based on the elapsed time t.

  The α value may be set for each object, may be set for each vertex of the polygon, or may be set for each pixel.

3. Processing of this Embodiment FIG. 9 is a flowchart showing a flow of rainbow object image generation processing of this embodiment.

  When the occurrence of a rainbow object display event is detected, the following processing is performed (step S10).

  First, a virtual projection plane is set in a direction opposite to the light source with respect to the viewpoint position (step S20).

  The first direction vector V1 is set by shifting it by a predetermined angle with respect to the direction of the light vector, the second direction vector V2 is set by shifting by a slight angle with respect to the first direction vector V1, and the V1 vector and V2 vector are set. To the virtual projection plane starting from the viewpoint position, and the intersections P1 and P2 of the V1 vector and V2 vector extensions and the virtual projection plane are obtained (step S30).

  Next, extending the ray vector from the viewpoint position toward the virtual projection plane, the intersection of the extension line of the ray vector and the virtual projection plane is obtained as the center O of the circle, and the radius of the circle is determined based on the center O and the intersections P1 and P2. The rainbow object is set by determining the position and size of the rainbow object based on the determined circle (step S40).

  Next, α value control information is generated so that the portion other than the display area set on the virtual projection plane of the rainbow object is transparent (step S50).

Next, based on the elapsed time t from the start of the rainbow object display, it is determined whether it is within the fade-in period or the fade-out period (step S60).
If it is within the fade-in period, control information for the α value is generated so that the rainbow object fades out based on the elapsed time t (steps S70 and S80).

  If it is within the fade-out period, α value control information is generated so that the rainbow object fades out based on the elapsed time t (steps S90 and S100).

  Next, the set rainbow object is perspective-transformed (step S110).

Then, the rainbow texture is mapped to the rainbow object that has been subjected to the perspective transformation, the α value is set based on the control information of the set α value, and the rainbow object is rendered semi-transparently (step S120).
4). Hardware Configuration FIG. 10 shows an example of a hardware configuration capable of realizing this embodiment. The main processor 900 operates based on a program stored in a CD 982 (information storage medium), a program downloaded via the communication interface 990, a program stored in the ROM 950, or the like, and includes game processing, image processing, sound processing, and the like. Execute. The coprocessor 902 assists the processing of the main processor 900, and executes matrix operation (vector operation) at high speed. For example, when a matrix calculation process is required for a physical simulation for moving or moving an object, a program operating on the main processor 900 instructs (requests) the process to the coprocessor 902.

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

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

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

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

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

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

  The present invention is not limited to that described in the above embodiment, and various modifications can be made.

  For example, terms (α values / luminance, gradient patterns, polygons, etc.) cited as broad or synonymous terms (texel values, texel value patterns, primitive surfaces, etc.) in the description or drawings are described in the specification or In other descriptions in the drawings, terms can be replaced with terms having a broad meaning or the same meaning.

  In the invention according to the dependent claims of the present invention, a part of the constituent features of the dependent claims can be omitted. Moreover, the principal part of the invention according to one independent claim of the present invention can be made dependent on another independent claim.

  Also, the texture mapping process is not limited to that described in the present embodiment, and a conversion process equivalent to these is also included in the scope of the present invention. The present invention can be applied to various games. Further, the present invention is applied to various image generation systems such as a business game system, a home game system, a large attraction system in which a large number of players participate, a simulator, a multimedia terminal, a system board for generating a game image, and a portable terminal. it can.

The functional block diagram of the image generation system of this embodiment. FIG. 2 is a diagram for explaining the first direction vector V1 and the second direction vector V2 set based on the light vector. The figure for demonstrating the method of setting a rainbow object based on the 1st direction vector V1 and the 2nd direction vector V2. The figure for demonstrating the shape setting method of the ring object of a rainbow object. It is a figure for demonstrating the relationship between the magnitude | size and position of a rainbow object set with a light source position (light source height). The figure for demonstrating the relationship between the size and position of the rainbow object set with a light source position (light source height). 6A and 6B are diagrams for explaining control of the display range of the rainbow object according to the present embodiment. The figure for demonstrating the fade-in / fade-out process of the rainbow object of this Embodiment. It is the figure shown about the relationship between elapsed time and (alpha) value. The flowchart figure which shows the flow of the image generation process of the rainbow object of this Embodiment. It is a hardware structural example.

Explanation of symbols

100 processing unit, 110 object space setting unit, 112 movement / motion processing unit, 114 virtual camera control unit, 116 rainbow object setting unit, 118 light source control unit, 120 drawing unit, 122 hidden surface removal unit, 124 texture mapping unit, 126 Alpha synthesis unit, 130 sound generation unit, 160 operation unit, 170 storage unit, 172 drawing buffer, 174 Z buffer, 176 texture storage unit, 180 information storage medium, 190 display unit, 192 sound output unit, 194 portable information storage device 196 Communication Department

Claims (10)

A program for generating an image visible from a virtual camera in an object space,
A light effect expression object setting unit that changes at least one of the shape, size, and appearance position of the light effect expression object based on the light source position or the direction of the light vector;
A drawing unit that draws an image of an object space in which a light effect expression object is arranged viewed from a virtual camera;
A program that causes a computer to function. In claim 1,
A program comprising a light source control unit that changes a light source position or a direction of a light vector according to a change in game time. In any one of Claims 1 thru | or 2.
The light effect expression object setting unit includes:
Set a virtual projection plane at a point away from the viewpoint position by a predetermined distance in the direction opposite to the light source,
The first direction vector V1 is set by shifting by a predetermined angle with respect to the direction of the ray vector, the second direction vector V2 is set by shifting by a slight angle with respect to the first direction vector V1, and the first direction The vector V1 and the second direction vector V2 are extended toward the virtual projection plane starting from the viewpoint position, and based on the intersection of the first direction vector V1 and the extension line of the second direction vector V2 and the virtual projection plane. A program that sets at least one of a shape, a size, and an appearance position of a light effect expression object. In any one of Claims 1 thru | or 3,
The light effect expression object setting unit includes:
Set a virtual projection plane at a point away from the viewpoint position by a predetermined distance in the direction opposite to the light source,
A direction vector V obtained by shifting by a predetermined angle with respect to the direction of the ray vector is extended from the viewpoint position to the virtual projection plane, and a first intersection that is an intersection of the extension line of the direction vector V and the virtual projection plane. And extending a ray vector from the viewpoint position toward the virtual projection plane, obtaining a second intersection that is an intersection of the extension line of the ray vector and the virtual projection plane, and producing a light effect based on the first intersection and the second intersection A program characterized in that at least one of the shape, size, and appearance position of an expression object is set. In any one of Claims 1 thru | or 4,
The light effect expression object setting unit includes:
A program characterized by setting an annular object as a light effect expression object. In any one of Claims 1 thru | or 5,
The light effect expression object setting unit includes:
A program characterized in that a light effect expression object is set to be arranged for a predetermined time at a given timing. In claim 6,
The light effect expression object setting unit includes:
At least one of a setting process for causing the light effect expression object to fade-in and displaying the light effect expression object in a predetermined period from the start of arrangement, and a setting process for causing the light effect expression object to fade out and display in a predetermined period before the arrangement ends. The program characterized by performing. In any one of Claims 1 thru | or 7,
The light effect expression object setting unit includes:
The display range control information for controlling the display range of the light effect expression object is set, and a process for setting the light effect expression object so that the portion outside the display range is not displayed based on the display range control information is performed. Program.   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 light effect expression object setting unit that changes at least one of the shape, size, and appearance position of the light effect expression object based on the light source position or the direction of the light vector;
A drawing unit that draws an image of an object space in which a light effect expression object is arranged viewed from a virtual camera;
An image generation system comprising:

Images