JP4632855B2 - Program, information storage medium, and image generation system - Google Patents

Description

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

  Conventionally, an image generation system (game system) that generates an image that can be seen from a virtual camera (a given viewpoint) in an object space that is a virtual three-dimensional space is known. Popular. Taking an image generation system capable of enjoying a role-playing game (RPG) as an example, a player operates a player character (player object), which is his or her own character, to move it on a map in the object space, and to create an enemy character. Enjoy the game by playing against (enemy objects), interacting with other characters, and visiting various towns.

  In such an image generation system, a post-filter method (post-effect method) is known in which an image drawn once (original image) is further processed to create an image having an atmosphere different from that of the original image. It has been. For example, a technique for blurring an original image using a blur filter, a technique for performing edge enhancement using a color difference filter, and the like are known. In addition, there is a fluctuation filter that distorts the original image with the passage of time to express the heat and fluctuations (ripples) of the water surface.

When you want to apply such a post-filter effect only to a specific part of the original image, specify the area that contains the image of the object to be filtered (the object to be filtered) as the effect area. There is a technique in which a filter image is texture-mapped to a virtual polygon having the size of an effect area and synthesized with an original image to reflect the effect of the filter image on the original image (see Patent Document 1). However, such a conventional method requires special processing for designating an effect area, and thus further simplification of processing is desired.
Japanese Patent No. 3467259

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a program, an information storage medium, and an image generation system that can easily perform partial filtering.

  (1) The present invention is an image generation system for generating an image viewed from a given viewpoint in an object space, and includes a geometry processing unit that performs geometry processing on an object, and the geometry-processed object. A filtering processing unit that performs a filtering process on the drawn original image, wherein the filtering target object is drawn with an α value different from that of other objects in the original image, and the filtering processing unit The present invention relates to an image generation system that performs the filtering process using an α value set in an α plane of an image as mask information. 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 an information storage medium that can be read by a computer and stores (records) a program that causes the computer to function as each of the above-described units.

  The computer refers to a physical device (system) having basic components such as a processor (processing unit: CPU or GPU), a memory (storage unit), an input device, and an output device. The same applies to the following.

  According to the present invention, it is possible to set information (mask information) for masking a non-permitted region for filter processing on the α plane of the original image generated by the drawing processing simply by drawing the object after the geometry processing. . Therefore, according to the present invention, the processing can be simplified when the filtering process is locally performed on the original image.

  (2) In the image generation system, the program, and the information storage medium of the present invention, the filter processing unit performs a blurring process or a pixel replacement process to generate a filter image corresponding to the original image. You may make it perform the filter process which synthesize | combines this filter image. For example, according to the blurring process, glare and soft focus can be expressed. In addition, for example, according to the pixel replacement process, fluctuations such as soot or hot flame can be expressed. As a method for synthesizing the original image and the filter image, for example, translucent drawing using an α test, normal α blending, or additive α blending can be employed.

  (3) In the image generation system, the program, and the information storage medium of the present invention, when the filter processing unit performs the filter processing including the blurring processing, the drawing area of the filter processing target object in the original image Only, a work image obtained by copying the α value set in the α plane of the original image as mask information is generated, the filter image is generated based on the work image, and the original image and the filter image are synthesized. You may make it perform the process to perform. In this way, it is possible to easily perform local glare expression and the like by performing blurring processing only on the portion that needs to be filtered.

  (4) Further, in the image generation system, the program, and the information storage medium of the present invention, when the filter processing unit performs the filter processing including the pixel replacement processing, the image processing system, the program, and the information storage medium are configured based on the work image copied from the original image. A filter image is generated, and only the drawing area of the filter processing target object in the filter image is combined with the original image using the α value set in the α plane of the original image as mask information. Good. In the pixel replacement process, if the color information of all the pixels of the original image is not used, an unnatural image with noise is generated. Therefore, the pixel replacement process is performed on the work image obtained by copying the entire original image. In addition, by causing the filter image and the original image to be synthesized only for the drawing region of the object to be filtered, it is possible to prevent a situation in which the generated image becomes unnatural.

  (5) In the image generation system, the program, and the information storage medium according to the present invention, the filter processing unit includes pixels that are lighter than a given reference color from each pixel of the original image or a blurred image corresponding to the original image. A filtering process including a color extracting process for extracting the image may be performed. Assuming that glare is generated in a portion drawn in a bright color in the image as described above, realistic glare expression can be performed without performing detailed light source calculation.

  (6) In the image generation system, the program, and the information storage medium of the present invention, the filter processing unit obtains the color information of the reference color from the color information of each pixel of the original image or the blurred image corresponding to the original image. The color extraction process may be performed by subtraction. In this way, since the component having a color darker than the reference color is cut, it is possible to easily specify only the area where the glare is necessary.

  (7) Further, the present invention is an image generation system for generating an image viewed from a given viewpoint in the object space, the geometry processing unit for performing geometry processing on the object, and the object subjected to the geometry processing A filter processing unit that generates a filter image corresponding to the original image on which the image is drawn, and performs a filter process for synthesizing the original image and the filter image. Are drawn with different α values, and the filter processing unit uses the α value set in the α plane of the original image as mask information for the first filter processing and the second filter processing for the original image. When performing at least one and performing the first filtering process, the filtering target object in the original image A drawing image of the original image is copied using the α value set in the α plane of the original image as mask information, a first filter image is generated based on the work image, and the original image and the When performing the process of combining with the first filter image and performing the second filter process, a second filter image is generated based on a work image obtained by copying the original image, and the second filter image The image generation system performs processing for combining only the drawing area of the filter processing target object with the original image using the α value set in the α plane of the original image as mask information. 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 an information storage medium that can be read by a computer and stores (records) a program that causes the computer to function as each of the above-described units.

  According to the present invention, it is possible to obtain mask information suitable for partial filter processing for various uses from the α plane of the same original image only by drawing a filtering target object with an α value different from that of other objects. it can.

  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 a player object (an example of a moving object, a player character operated by the player), and functions thereof are a lever, a button, a steering, a microphone, and a touch panel display. Alternatively, it can be realized by a housing or the like. The storage unit 170 serves as a work area for the processing unit 100, the communication unit 196, and the like, and its function can be realized by a RAM (VRAM) or the like.

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

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

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

  Note that a program (data) for causing a computer to function as each unit of 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 communication unit 196. May be. Use of the information storage medium of such a host device (server) can also be included in the scope of the present invention.

  The processing unit 100 (processor) performs processing such as game processing, image generation processing, or sound generation processing based on operation data and programs from the operation unit 160. Here, as the game process, a process for starting a game when a game start condition is satisfied, a process for advancing the game, a process for placing an object such as a character or a map, a process for displaying an object, and a game result are calculated. There is a process or a process of ending a game when a game end condition is satisfied. The processing unit 100 performs various processes using the main storage unit 171 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, 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. 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 character, a car, or an airplane). That is, based on operation data input by the player through the operation unit 160, a program (movement / motion algorithm), various data (motion data), or the like, the object is moved in the object space, or the object is moved (motion, animation). ) Is performed. 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.

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

  For example, when an object (eg, character, ball, car) is photographed from behind using a virtual camera, the position or rotation angle of the virtual camera (the direction of the virtual camera is set so that the virtual camera follows changes in the position or rotation of the object. ) To control. In this case, the virtual camera can be controlled based on information such as the position, rotation angle, or speed of the object obtained by the movement / motion processing unit 112. Alternatively, the virtual camera may be controlled to rotate at a predetermined rotation angle or to move along a predetermined movement path. In this case, the virtual camera is controlled based on the virtual camera data for specifying the position (movement path) or rotation angle of the virtual camera. When there are a plurality of virtual cameras (viewpoints), the above-described control process is performed for each virtual camera.

  The 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. In the case of generating a so-called three-dimensional game image, first, geometric processing such as coordinate transformation (world coordinate transformation, camera coordinate transformation), clipping processing, or perspective transformation is performed, and drawing data ( Primitive vertex position coordinates, texture coordinates, color data, normal vector, α value, etc.) are created. Then, based on the drawing data (object data), the model object (one or a plurality of primitives) after perspective transformation (after geometry processing) is converted into a pixel unit such as a drawing buffer 172 (frame buffer or intermediate buffer (work buffer)). The image information is stored in a buffer (VRAM). Thereby, an image that can be seen from the virtual camera (given viewpoint) in the object space is generated. In addition, when there are a plurality of virtual cameras (viewpoints), the drawing process can be performed so that an image seen from each virtual camera can be displayed as a divided image on one screen.

  The drawing unit 120 includes a geometry processing unit 122 and a filter processing unit 124.

  The geometry processing unit 122 performs geometry processing such as coordinate transformation, clipping processing, perspective transformation, or light source calculation on the object. Then, object data (positional coordinates of object vertices, texture coordinates, color data, normal vector, α value, etc.) after geometry processing (after perspective transformation) is stored in the main storage unit 172.

  The filter processing unit 124 performs a filter process on the original image on which the geometry-processed object is drawn. As filter processing, blurring processing, pixel replacement processing, and the like can be performed. At that time, a filter image corresponding to the original image is generated, and the original image and the filter image are combined to filter the original image. Processing can be performed. As a synthesis method of the original image and the filter image, there are α blending (usually α blending, addition α blending, subtraction α blending) and translucent drawing using an α test.

  In this embodiment, an original image is created by drawing an object after geometry processing. In the original image, an object to be filtered is drawn with an α value different from other objects. Then, the filter processing unit 124 performs a filter process using the α value set in the α plane of the original image as mask information. As a result, it is possible to generate an image in which the effect of the filter processing is added only to a given drawing area of the original image.

  As a technique for rendering the α value set in the α plane of the original image to be mask information, the α component of the vertex color of the object to be filtered is set to α ≧ α1, and the vertex of another object is set to α ≧ α1. The method of setting the α component of the vertex color to α <α1, α ≧ α1 is set to the α plane of the texture mapped to the object to be filtered, and α <α is set to the α plane of the texture mapped to the other object. A method of setting α1, or a value obtained by multiplying the α component of the vertex color of the object to be filtered by the α value set in the α plane of the texture for the object to be filtered so that α ≧ α1. The value obtained by multiplying the α component of the vertex color of the other object by the α value set in the α plane of the texture for the other object is α <α1 So as there is a method such as to set in. When the mask information is set in the α component of the vertex color of the object, the object data is stored in the object data storage unit 176. When the mask information is set for the α plane of the texture, the texture mapped to the object is stored in the texture storage unit 173.

  The filter processing unit 124 switches the usage of the mask information (α value) set in the α plane of the original image according to the content of the filter processing.

  For example, when performing filter processing (first filter processing) including blurring processing, only the drawing area of the object to be filtered in the original image is used as mask information using the α value set in the α plane of the original image. A copied work image is generated, a filter image is generated based on the work image, and a process of combining the original image and the filter image is performed.

  Also, for example, when performing a filter process including a pixel replacement process (second filter process), a filter image is generated based on a work image obtained by copying the entire original image, and the filter processing target object of the filter image is generated. Only the drawing area is combined with the original image using the α value set in the α plane of the original image as mask information.

  The drawing unit 120 can perform texture mapping, hidden surface removal processing, α blending, and the like as other drawing processing.

  Texture mapping is a process for mapping a texture (texel value) stored in the texture storage unit 176 to an object. Specifically, the texture (surface properties such as color and α value) is read from the texture storage unit 176 using texture coordinates or the like set (given) to the vertex of the object. Then, a texture that is a two-dimensional image is mapped to an object. In this case, bilinear interpolation or the like is performed as processing for associating pixels with texels or texel interpolation.

  In the present embodiment, text mapping using a color look-up table (CLUT) for index color / texture mapping stored in the LUT storage unit 175 can also be performed as texture mapping. In this case, an index texture in which a number (color) determined based on the relative position of each pixel of the original image or the relative position of each pixel of the divided block obtained by dividing the original image is set as an index number (index color) is used. While referring to a color lookup table that associates index numbers with image information (R component, G component, B component, A component (α component)), virtual objects (display screen size polygons, divided block size polygons) ) Texture mapping. When performing pixel replacement processing, prepare an index texture to replace the index number assigned to each texel of the index texture corresponding to the original image or the divided block of the original image, and use the color lookup table for the index texture. A pixel replacement image (an example of a filter image) can be generated by performing texture mapping on a virtual object while referring to the image.

  As the hidden surface removal processing, hidden surface removal processing may be performed by a Z buffer method (depth comparison method, Z test) using a Z buffer 178 (depth buffer) in which a Z value (depth information) of a drawing pixel is stored. it can. That is, when the drawing pixel corresponding to the primitive of the object is drawn, the Z value stored in the Z buffer 174 is referred to. Then, the Z value of the referenced Z buffer 174 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 174 is updated to a new Z value.

  As the α blending, a translucent synthesis process (usually α blending, addition α blending, subtraction α blending, or the like) based on the α value (A value) is performed. For example, in the case of normal α blending, the following processes (1) to (3) are performed.

R _Q = (1−α) × R ₁ + α × R ₂ (1)
G _Q = (1−α) × G ₁ + α × G ₂ (2)
B _Q = (1−α) × B ₁ + α × B ₂ (3)
In addition, in the case of addition α blending, the following expressions (4) to (6) are performed. In the case of simple addition, α = 1 and the following formulas (4) to (6) are performed.

R _Q = R ₁ + α × R ₂ (4)
G _Q = G ₁ + α × G ₂ (5)
B _Q = B ₁ + α × B ₂ (6)
In the case of subtractive α blending, the processing of the following equations (7) to (9) is performed. In the case of simple subtraction, α = 1 and the following formulas (7) to (9) are processed.

R _Q = R ₁ −α × R ₂ (7)
G _Q = G ₁ −α × G ₂ (8)
B _Q = B ₁ −α × B ₂ (9)
Here, R ₁ , G ₁ , B ₁ are RGB components of an image (original image) already drawn in the drawing buffer 172, and R ₂ , G ₂ , B ₂ should be drawn in the drawing buffer 172. This is the RGB component of the image. R _Q , G _Q , and B _Q are RGB components of an image obtained by α blending. The α value is information that can be stored in association with each pixel (texel, dot), for example, plus alpha information other than color information. The α value can be used as 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. In the following description, the case where the method of the present embodiment is employed with respect to the filter processing for expressing glare or the filter processing for expressing fluctuations such as ripples will be mainly described. It can be applied not only to such filter processing but also to various filter processing.

2.1 Glare Filter Method In this embodiment, the α value set in the α plane of the original image is treated as mask information, and the glare filter is selectively applied to the drawing area of the object to be filtered in the original image and its periphery. A method of applying processing is adopted.

  Specifically, as indicated by A1 in FIG. 2, when the objects OB1 to OB3 existing in the scene (in the view volume) seen from the virtual camera arranged in the object space are drawn in the frame buffer, the filter processing target The object OB1, which is an object, is drawn with a different α value from the other objects OB2 and OB3 to generate an original image. In the example shown in FIG. 2, the object OB1 is drawn with α1, the object OB2 is drawn with α2 having a value smaller than α1, and the object OB3 is also drawn with α2 having a value smaller than α1. In the example shown in FIG. 2, an α value serving as mask information is set for the α component (A component) of the vertex color of each object. That is, the mask information is obtained from the object data after the geometry processing.

  When the glare filter is applied to the original image drawn in the frame buffer, as shown by A2 in FIG. 2, an α test is performed using the α value set in the α plane of the original image as mask information, and α Only the drawing area of ≧ α1 is reduced and copied to a work buffer smaller in size than the frame buffer. At this time, the image information in the work buffer must be cleared (filled in black). In the example shown in FIG. 2, since α ≧ α1 is only the object OB1 to be filtered, only the drawing area of the object OB1 is reduced and copied as indicated by A3 in FIG. Then, color extraction processing and blurring processing are performed on the image (work image) reduced and copied to the work buffer to generate a filter image for glare expression as indicated by A4 in FIG.

  Here, as the color extraction process, a process is performed in which a color brighter than the reference color is extracted from each pixel of the work image and the color information of the difference is obtained. For example, as shown in B1 of FIG. 3, a single-color virtual polygon (single-color polygon) in which the reference color C1 is set to the vertex color is prepared, and the single-color polygon is drawn in the work buffer with translucency. As a result, as shown in B2 of FIG. 3, if the color of an arbitrary pixel P of the work image is C2, the color of the pixel P of the color extraction image created in the work buffer after rendering the monochrome polygon subtracted semi-transparently Becomes C2-C1. That is, in the color extraction image, a color darker than the reference color is clamped to black, and a lighter color than the reference color is a difference color. Thus, by obtaining only colors brighter than a certain reference color, it is possible to specify an area where glare is likely to occur.

  In addition, as blurring processing, it is possible to blur the image by interpolating the color information of each pixel by bilinear filter method by repeatedly reducing and enlarging the image, and by performing texture mapping by bilinear filter method while shifting texture coordinates. There is a method of blurring an image by interpolating pixel color information. The blurring processing method is not limited to the above, and various methods can be employed. For example, the method of blurring an image by texture mapping using the bilinear filter method is to set the work image of the work buffer as a texture as shown by D1 in FIG. 4, and shift the texture coordinates to a virtual polygon of the work buffer size. It is realized by mapping. For example, as shown in D2 of FIG. 4, the texture coordinates are shifted in the X direction (horizontal direction) and the texture based on the work image is texture-mapped to the virtual polygon, or the texture coordinates are changed as shown in D3 of FIG. By shifting the texture based on the work image to the virtual polygon by shifting in the Y direction (vertical direction), the color information of each pixel of the work buffer is interpolated by the bilinear filter method, and the image becomes blurred. At this time, by repeatedly performing the process indicated by D2 and the process indicated by D3 in FIG. 4, the degree of blurring of the image can be further increased.

  In the glare filter method of this embodiment, as shown in A5 of FIG. 2, the filter image created in the work buffer by performing color extraction processing and blurring processing on the work image is added to the original image of the frame buffer and synthesized. Thus, it is possible to generate an image in which glare processing is performed only in the vicinity of the drawing area of the object OB1 in the original image. Note that the addition synthesis of the original image and the filter image can be performed by addition α blending. In addition, if the glare filter method of the present embodiment is performed by normal α blending for the method of combining the original image and the filter image, it can be applied to soft focus expression by filter processing.

2.2 Fluctuation Filter Method In this embodiment, the α value set in the α plane of the original image is treated as mask information, and the fluctuation filter processing is selectively performed on the drawing area of the object to be filtered in the original image. The method is adopted.

  Specifically, as indicated by E1 in FIG. 5, the object to be filtered (filtering target object) OB1 (α = α1) is changed to another object OB2 (α = α2) and OB3 (α = α3). The original image is generated by drawing with a different α value. At this time, as indicated by E4 in FIG. 5, the filter processing is performed only on the drawing region of the object OB1 to be filtered by combining the filter image only in the region of α ≧ α1 (semi-transparent drawing) by the α test. Can be generated. Also in the example shown in FIG. 5, an α value serving as mask information is set for the α component (A component) of the vertex color of each object. That is, the mask information is obtained from the object data after the geometry processing. As described above, in the fluctuation filter method of the present embodiment, the mask information can be drawn on the α plane of the original image only by drawing the filtering target object OB1 subjected to the geometry processing.

  In the present embodiment, as shown by E3 in FIG. 5, a pixel replacement process is performed on the work image to generate a filter image. At this time, a pixel replacement process in which the pixel replacement distance fluctuates periodically is performed using an index color / texture mapping technique.

  Specifically, as shown in F1 of FIG. 6, a filter image (filter image generated by dividing the original image drawn in the drawing buffer into a plurality of divided blocks and performing pixel replacement processing in units of the divided blocks. A filtering process is performed to synthesize (semi-transparent drawing) the image of the processed object) with the original image.

  At this time, each divided block has a size of, for example, 16 × 16 pixels, and can be handled as a color lookup table in which these 256 pixels are indexed based on their relative positions, as indicated by F2 in FIG. . Further, as indicated by F3 in FIG. 6, a shift table in which the position of each pixel of the divided block is shifted can be prepared separately from the color lookup table (CLUT), and the shift table can be handled as an index texture. In the shift table, the index number determined based on the relative position of the pixel of the divided block is handled as the coordinate value of the pixel in the divided block, and the index number of the pixel shifted by the pixel replacement distance ΔY is set for each pixel.

  Then, as indicated by F4 in FIG. 6, the index texture set based on the shift table is texture-mapped with respect to the polygon (virtual object) having the divided block size while referring to the color lookup table. Then, as indicated by F5 in FIG. 6, a polygon having a divided block size obtained by texture mapping the index texture is drawn at a corresponding position in the original image. By doing in this way, the process which replaces the pixel of an original image is realizable. These processes can be performed on all the divided blocks to generate a filter image corresponding to the original image. Finally, as shown at F6 in FIG. 6, a filter process for applying a post effect to the original image can be performed by synthesizing the filter image with the original image.

  In the pixel replacement process of this embodiment, the pixel replacement distance ΔY is set based on a periodic function as shown in FIG. That is, the shift table set in the index texture is rewritten according to the periodically changing pixel replacement distance ΔY. A plurality of index textures in which the pixel replacement distance ΔY is periodically changed may be prepared in advance. The periodic function is represented by the following formula (A).

ΔY = Asin (ωt + f (x, y)) (A)
As shown in FIG. 7, A is an amplitude component parameter. ω is a frequency component parameter. f (x, y) is an initial phase parameter determined based on the position of the pixel in the divided block. Among these parameters, parameters that are largely related to the strength of the filter processing are the amplitude component parameter A and the frequency component parameter ω. When the amplitude component parameter A is increased, the pixel replacement distance ΔY is increased, and the fluctuation can be increased. Further, when the frequency component parameter ω is reduced, the pixel replacement period 2π / ω is shortened, so that the fluctuation speed is increased and the fluctuation per unit time can be increased.

  By the way, as shown in FIG. 5, when creating a filter image after pixel replacement in the work buffer, it is preferable to copy the entire original image to the work buffer as shown by E2 in FIG. In contrast to this, a method of performing partial copying in which only the filtering target object OB1 is drawn in the work buffer is conceivable. However, in this case, color information other than the filtering target object OB1 is lost, and that If the pixels are replaced in a state, an unnatural color protrusion appears in the filter image. For this reason, as shown in E2 of FIG. 5, the entire original image is copied to the work buffer, and a pixel replacement process is performed on the copy image (work image) to generate a filter image. It is possible to avoid the inconvenience that an unnatural color protrudes.

3. Processing of this Embodiment Next, a detailed processing example of this embodiment will be described with reference to the flowcharts of FIGS.

  First, the glare filter process will be described with reference to the flowchart of FIG.

  First, an original image is generated by drawing a scene viewed from the virtual camera in a frame buffer so that the α value of a region where glare occurs is α1 (for example, 128) or more and the α value of a region where glare does not occur is less than α1. (Step S20).

  Next, the work buffer (first work buffer) WB1 having a size half that of the frame buffer is cleared. That is, the work buffer WB1 is painted black (R, G, B) = (0, 0, 0) (step S21).

  Next, the original image of the frame buffer is reduced and copied to the work buffer WB1 (step S22). At that time, the state of the most significant bit of the α value bit string is determined using an α test, and partial reduced copy is performed to reduce and copy to the work buffer only for pixels having an α value of α1 (eg, 128) or more. Then, the monochrome polygon image is subtracted and synthesized in the work buffer WB1 (step S23). That is, a component having a low color intensity is dropped by the color extraction processing described with reference to FIG.

  Next, the image of the work buffer WB1 is reduced and copied to a work buffer (second work buffer) WB2 having a size of 1/4 of the frame buffer (step S24). Then, using the method described in D1 and D2 of FIG. 4, an image obtained by shifting the image of the work buffer WB2 horizontally is added to the work buffer WB2, and the image is blurred in the horizontal direction (X direction). (Step S25). Further, using the method described in D1 and D3 of FIG. 4, an image obtained by shifting the image in the work buffer WB2 vertically is added to the work buffer WB2, and the image is blurred in the vertical direction (Y direction). This is performed (step S26).

  Next, the image of the work buffer WB2 is reduced and copied to a work buffer (third work buffer) WB3 having a size of 1/8 of the frame buffer (step S27). Then, in the same manner as in step S25, an image obtained by shifting the image of the work buffer WB3 horizontally is added and synthesized to the work buffer WB3, and a process of blurring the image in the horizontal direction (X direction) is performed (step S28). Further, the image obtained by shifting the image of the work buffer WB3 vertically is added and synthesized to the work buffer WB3 by the same method as in step S26, and a process of blurring the image in the vertical direction (Y direction) is performed (step S29).

  Next, the image of the work buffer WB2 is enlarged to the size of the frame buffer, and the enlarged image is multiplied by an appropriate coefficient (first α value) and added to the frame buffer and synthesized (step S30). Further, the image in the work buffer WB3 is enlarged to the size of the frame buffer, and the enlarged image is multiplied and combined with an appropriate coefficient (second α value) in the frame buffer (step S31).

  Next, the fluctuation filter process will be described with reference to the flowchart of FIG.

  First, an original image is generated by drawing a scene viewed from the virtual camera in a frame buffer so that the α value of a region where ripples occur is α1 (for example, 128) or more and the α value of a region where ripples do not occur is less than α1. (Step S10).

  Next, on the basis of change information such as the position, direction, and angle of view of the virtual camera, whether the wave should be strengthened (whether the wavefront motion will increase) or the wave should be weakened (whether the wavefront motion will be small) Determine (step S11). For example, if the moving distance of the gazing point of the virtual camera exceeds a threshold value, it is determined that the wave should be weakened. In addition, for example, when the moving distance of the point of sight of the virtual camera changes from a state where it exceeds the threshold value to fall below the threshold value, it is determined that the wave should be strengthened.

  Next, a filter strength parameter setting process is performed. Specifically, the wave strength level (first level) when the wavefront motion is large and the wave strength level (second level) when the wavefront motion is small and ripples are set in advance. If the current wave intensity level is determined to be different from the target wave intensity level by comparing the current wave intensity level with the target value, Is performed so that the intensity value (amplitude component parameter or frequency component parameter of the periodic function) approaches the target value (first level or second level) (step S12).

  Next, based on the wave intensity level set in step S12, table data (shift table) for shifting the position coordinates of each point of the pixel is created (step S13). This table data is handled as an index texture in the index color / texture mapping.

  Next, a work buffer (reduction buffer) having a size half that of the frame buffer (display screen) is prepared, and the entire screen (original image) is reduced and copied to the work buffer (step S14).

  Next, the screen (work image) reduced and copied to the work buffer is divided into blocks each having a size of 16 × 16 (pixels), and each divided block is divided into 256 colors indexed by relative positions in the block. It is regarded as a lookup table (CLUT) and is set as a color lookup table for index color / texture mapping (step S15).

  Next, the table data for shifting the pixel position coordinates is regarded as an index texture of 256 colors, and the index texture is mapped to the position corresponding to each divided block while referring to the color lookup table set in step S15. A polygon (virtual object) is drawn (step S16). As a result, a filter image is created in the work buffer.

  Next, the work buffer for storing the image (filter image) subjected to the pixel replacement process is enlarged to the size of the frame buffer and written to the frame buffer (step S17). At this time, the α test is used to determine the state of the most significant bit of the α value bit string, and the pixels of the image obtained by enlarging the image stored in the work buffer only to pixels having an α value of α1 (for example, 128) or more are half. Combine with the original image of the frame buffer by transparent drawing.

4). Hardware Configuration FIG. 8 shows an example of a hardware configuration capable of realizing this embodiment. The main processor 900 operates based on a program stored in a DVD 982 (information storage medium, which may be a CD), a program downloaded via the communication interface 990, a program stored in the ROM 950, or the like. Perform processing, sound processing, etc. The coprocessor 902 assists the processing of the main processor 900, and executes matrix operation (vector operation) at high speed. For example, when a matrix calculation process is required for a physical simulation for moving or moving an object, a program operating on the main processor 900 instructs (requests) the process to the coprocessor 902.

  The geometry processor 904 performs geometry processing such as coordinate conversion, perspective conversion, light source calculation, and curved surface generation based on an instruction from a program operating on the main processor 900, and executes matrix calculation at high speed. The data decompression processor 906 performs decoding processing of the 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 (vertex data and other parameters) to the drawing processor 910 and, if necessary, the texture to the texture storage unit 924. Forward. 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 DVD drive 980 (may be a CD drive) accesses a DVD 982 (may be a CD) in which programs, image data, sound data, and the like are stored. The communication interface 990 performs data transfer with the outside via a network (communication line, high-speed serial bus).

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

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

  The present invention is not limited to that described in the above embodiment, and various modifications can be made. For example, terms cited as broad or synonymous terms in the description in the specification or drawings can be replaced with broad or synonymous terms in other descriptions in the specification or drawings. Further, the glare filter method, the soft focus method, the fluctuation filter method, and the like are not limited to those described in the present embodiment, and methods equivalent to these are also included in the scope of the present invention.

  The present invention can also be applied to various games (such as fighting games, shooting games, robot fighting games, sports games, competitive games, role playing games, music playing games, dance games, etc.). Further, the present invention is applied to various image generation systems such as a business game system, a home game system, a large attraction system in which a large number of players participate, a simulator, a multimedia terminal, a system board for generating a game image, and a mobile phone. it can.

The functional block diagram of the image generation system of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. The flowchart which shows the specific process example of this embodiment. The flowchart which shows the specific process example of this embodiment. Hardware configuration example.

Explanation of symbols

100 processing unit,
110 Object space setting unit, 112 Movement / motion processing unit,
114 virtual camera control unit,
120 drawing units, 122 geometry processing units, 124 filter processing units,
130 sound generation unit, 160 operation unit, 170 storage unit,
171 main storage unit, 172 drawing buffer, 173 texture storage unit,
174 Z buffer, 175 LUT storage unit, 176 Object data storage unit,
180 information storage medium, 190 display unit, 192 sound output unit,
194 Portable information storage device, 196 communication unit

Claims (3)

A program for generating an image viewed from a given viewpoint in an object space,
A geometry processing unit that performs geometry processing on objects;
As a filter processing unit that generates a filter image corresponding to an original image on which the geometry-processed object is drawn, and performs a filter process for synthesizing the original image and the filter image,
Make the computer work,
In the original image, the filtering target object is drawn with a different α value from other objects,
The filter processing unit
Performing at least one of the first filter processing and the second filter processing on the original image using the α value set in the α plane of the original image as mask information,
When performing the first filter processing, a work image is generated by copying only the drawing area of the object to be filtered among the original image using the α value set in the α plane of the original image as mask information. , Generating a first filter image based on the work image, and performing a process of combining the original image and the first filter image,
When performing the second filter processing, a second filter image is generated based on a work image obtained by copying the original image, and only the drawing region of the filter processing target object is included in the second filter image. A program for performing processing for combining an α value set in an α plane of the original image as mask information with the original image. An information storage medium readable by a computer, wherein the program according to claim 1 is stored. An image generation system for generating an image viewed from a given viewpoint in an object space,
A geometry processing unit that performs geometry processing on objects;
A filter processing unit that generates a filter image corresponding to the original image on which the geometry-processed object is drawn, and performs a filter process for combining the original image and the filter image;
Including
In the original image, the filtering target object is drawn with a different α value from other objects,
The filter processing unit
Performing at least one of the first filter processing and the second filter processing on the original image using the α value set in the α plane of the original image as mask information,
When performing the first filter processing, a work image is generated by copying only the drawing area of the object to be filtered among the original image using the α value set in the α plane of the original image as mask information. , Generating a first filter image based on the work image, and performing a process of combining the original image and the first filter image,
When performing the second filter processing, a second filter image is generated based on a work image obtained by copying the original image, and only the drawing region of the filter processing target object is included in the second filter image. An image generation system for performing processing for combining an α value set in an α plane of the original image with the original image as mask information.