JP2009075867A - Program for image processing, computer-readable recording medium with the program recorded thereon, image processor, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing technology for further increasing power of expression of a handwritten-like image. <P>SOLUTION: This image processor is provided with a storage means and an arithmetic means, and the arithmetic means (a) generates basic image data by perspectively projecting a virtual three-dimensional space on a prescribed perspective projection face; (b) calculates a fog value representing transparency of the virtual three-dimensional space according to a distance between a camera position and an object arranged in the virtual three-dimensional space; (c) setting a density map representing a density value associated with basic image data on the basis of the fog value; (d) reading texture data from a storage means; and (e) generating the two-dimensional image data by combining the texture data with the basic image data by a rate corresponding to the density value set by the density map. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for generating a two-dimensional image by perspective-projecting an event set in a virtual three-dimensional space.

  With the development of computer technology in recent years, image processing technology relating to video game devices, simulators (pseudo-experience devices), etc. has become widely popular. In such a system, it is important to make the displayed image richer in expressiveness in order to increase the product value. In such a background, expression that is close to reality (realistic expression) is distinct, and handwritten-style image expression such as watercolor style or drawing style has been studied (for example, see Patent Document 1).

  A real watercolor painting or the like is created by applying paint (paint, charcoal, etc.) on the canvas. At this time, it is often the case that the pattern of the background of the portion can be visually recognized due to unpainted paint or uneven coating, and this is one of the important factors that create an atmosphere such as a watercolor painting. For this reason, even when an image simulating a watercolor painting or the like is generated, the expression of the ground pattern is important in order to enhance the expressive power. Therefore, there is a demand for an image processing technique capable of freely expressing the background pattern as described above with an appropriate calculation load.

JP 2007-26111 A

  Therefore, an object of the present invention is to provide an image processing technique that can further enhance the expressiveness of handwritten-style images.

  A program for image processing according to an aspect of the present invention is a two-dimensional image obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane, which is executed by an image processing apparatus including a storage unit and a calculation unit. A program for generating data, wherein: (a) a viewpoint is arranged in the virtual three-dimensional space, and perspective projection is performed on the perspective projection plane set corresponding to the viewpoint; And (b) storing the basic image data in the storage means, and (b) depending on the distance between the viewpoint position and the object arranged in the virtual three-dimensional space. Calculating a fog value indicating transparency; and (c) setting a density map indicating a density value associated with the basic image data based on the fog value, and storing the density map in the storage unit Storing, (d) reading out texture data from the storage means, and (e) combining the texture data with the basic image data at a ratio according to the density value set by the density map. Generating the two-dimensional image data. Here, as the texture data, for example, data including an image of a canvas pattern is used.

  Preferably, in (b), when the distance between the viewpoint and the object is smaller than a predetermined threshold value, the fog value is set to a constant value.

 Preferably, in (c), the density map is set using the fog value as the density value as it is.

  A program for image processing according to another aspect of the present invention is executed by an image processing apparatus including a storage unit and a calculation unit, and is obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane. A program for generating image data, wherein: (a) a viewpoint is arranged in the virtual three-dimensional space, and a perspective image is projected onto the perspective projection plane set corresponding to the viewpoint; Generating data and storing the basic image data in the storage means; and (b) a camera vector indicating the direction of the viewpoint and a normal vector of a polygon of an object arranged in the virtual three-dimensional space. A step of calculating an inner product value; and (c) setting a density map indicating a density value associated with the basic image data based on the inner product value, and storing the density map in the storage means. (D) reading the texture data from the storage means; and (e) combining the texture data with the basic image data at a ratio according to the density value set by the density map. Generating the two-dimensional image data. Here, as the texture data, for example, data including an image of a canvas pattern is used.

  Preferably, in (c), with respect to the inner product value, the smaller the inner product value, the larger the density value, and when the inner product value is 0, the data conversion is performed so that the density value becomes the maximum value. And the density map is set based on the density value obtained by the data conversion.

  The computer-readable recording medium according to the present invention is a recording medium on which the program according to the present invention is recorded. The present invention can also be expressed as an image processing apparatus and an image processing method as follows.

  An image processing apparatus according to an aspect of the present invention is an image processing apparatus that includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane. The arithmetic means (a) arranges a viewpoint in the virtual three-dimensional space, and performs perspective projection on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image Means for storing data in the storage means; and (b) calculating a fog value representing the transparency of the virtual three-dimensional space according to the distance between the position of the viewpoint and the object arranged in the virtual three-dimensional space. Means, (c) a density map indicating density values associated with the basic image data is set based on the fog value, and the density map is stored in the storage means; (d) texture data is Memory And (e) means for generating the two-dimensional image data by synthesizing the texture data with the basic image data at a ratio corresponding to the density value set by the density map. It is characterized by doing.

  An image processing apparatus according to another aspect of the present invention is an image processing apparatus that includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane. The arithmetic means (a) arranges a viewpoint in the virtual three-dimensional space, and performs perspective projection on the perspective projection plane set corresponding to the viewpoint to generate basic image data. Means for storing image data in the storage means; (b) means for calculating an inner product value of a camera vector indicating the direction of the viewpoint and a normal vector of a polygon of an object arranged in the virtual three-dimensional space; c) means for setting a density map indicating density values associated with the basic image data based on the inner product value and storing the density map in the storage means; and (d) texture data stored in the storage means. Means for reading, and (e) means for generating the two-dimensional image data by synthesizing the texture data with the basic image data at a ratio corresponding to the density value set by the density map. It is characterized by doing.

 An image processing method according to an aspect of the present invention is a two-dimensional image obtained by perspectively projecting a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane in an image processing apparatus including a storage unit and a calculation unit. An image processing method for generating image data, wherein the computing means (a) places a viewpoint in the virtual three-dimensional space, and performs perspective projection on the perspective projection plane set corresponding to the viewpoint. Generating basic image data and storing the basic image data in the storage means; and (b) the virtual tertiary according to a distance between the position of the viewpoint and the object arranged in the virtual three-dimensional space. Calculating a fog value representing the transparency of the original space; and (c) setting a density map indicating a density value associated with the basic image data based on the fog value; Storing in the storage means, (d) reading out the texture data from the storage means, and (e) the basic image data at a ratio according to the density value set by the density map. Generating the two-dimensional image data by synthesizing each of the steps.

  An image processing method according to another aspect of the present invention is obtained by perspectively projecting a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane in an image processing apparatus including a storage unit and a calculation unit. An image processing method for generating dimensional image data, wherein the computing means (a) arranges a viewpoint in the virtual three-dimensional space and performs perspective projection on the perspective projection plane set corresponding to the viewpoint. Generating basic image data and storing the basic image data in the storage means; (b) a camera vector indicating the direction of the viewpoint and a normal of the polygon of the object arranged in the virtual three-dimensional space Calculating an inner product value with a vector; and (c) setting a density map indicating a density value associated with the basic image data based on the inner product value, and storing the density map in the memory (D) reading texture data from the storage means; and (e) combining the texture data with the basic image data at a rate corresponding to the density value set by the density map. And generating each of the two-dimensional image data.

  Embodiments of the present invention will be described below. In the following, a game device is taken as an example of an image processing device.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the game apparatus. 1 includes a CPU (Central Processing Unit) 10, a system memory 11, a storage medium 12, a boot ROM (BOOT ROM) 13, a bus arbiter 14, a GPU (Graphics Processing Unit) 16, a graphic memory 17, and an audio processor 18. , An audio memory 19, a communication interface (I / F) 20, and a peripheral interface 21. That is, the game apparatus 1 of this embodiment includes a CPU 10 and a GPU 16 as calculation means (calculation unit), a system memory 11 as a storage means (storage unit), a storage medium 12, a graphic memory 17, an audio memory 19, and the like. Composed. In other words, the game apparatus 1 includes a computer (computer system) mainly configured by the CPU 10 and functions as a game apparatus by causing the computer to execute a predetermined program. Specifically, the game device 1 sequentially generates a two-dimensional image of a virtual three-dimensional space (game space) viewed from a given viewpoint (virtual camera) and provides sound effects, etc. Generate the voice of

  A CPU (Central Processing Unit) 10 controls the entire game apparatus 1 by executing a predetermined program.

  The system memory 11 stores programs and data used by the CPU 10. The system memory 11 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) and an SRAM (static random access memory).

  The storage medium 12 stores data such as game programs and output images and sounds. The storage medium 12 as the program data ROM includes an IC memory that can electrically read data such as mask chrome and flash ROM, a device that can read data optically such as a CD-ROM and a DVD-ROM, and an optical disk or magnetic disk. It may be a disc or the like.

  The boot ROM 13 stores a program for initializing each block when the game apparatus 1 is activated.

  The bus arbiter 14 controls a bus for exchanging programs and data between the blocks.

  The GPU 16 generates an image to be output to the display based on the calculation of the position coordinates and orientation (geometry calculation) of the object displayed on the display in the virtual three-dimensional space (game space) and the orientation and position coordinates of the object. Perform processing (rendering processing).

  The graphic memory 17 is connected to the GPU 16 and stores data and commands for generating an image. The graphic memory 17 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) or an SRAM (static random access memory). The graphic memory 17 functions as various buffers used during image generation, such as a frame buffer and a texture buffer.

  The audio processor 18 generates data for outputting sound from the speaker. The audio data generated by the audio processor 18 is converted into an analog signal by a digital / analog converter (not shown) and input to the speaker, so that the speaker outputs audio.

  The audio memory 19 is configured in the audio processor 18 and stores data and commands for generating sound. The audio memory 19 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) or an SRAM (static random access memory).

  The communication interface (I / F) 20 performs communication processing when the game apparatus 1 needs to perform data communication with other game apparatuses, server apparatuses, and the like.

  The peripheral interface (I / F) 21 incorporates an interface for inputting and outputting data from the outside, and a peripheral as a peripheral device is connected thereto. Here, peripherals include a mouse (pointing device), a keyboard, switches for key operations such as a game controller, and a touch pen, as well as a backup memory for storing program progress and generated data, a display device, and shooting. And devices that can be connected to the image processing apparatus main body or other peripherals.

  The system memory 11, the graphic memory 17, and the sound memory 19 may be connected to the bus arbiter 14 and used in common for each function. Moreover, each functional block should just exist as a function, and functional blocks may be integrated, and each component inside a functional block may be isolate | separated as another block.

  The game device according to the present embodiment has the above-described configuration. Next, the contents of the image generation processing of the present embodiment will be described.

  FIG. 2 is a conceptual diagram showing each of an object (virtual object), a light source, and a viewpoint arranged in a virtual three-dimensional space. The object 300 is a virtual object formed using one or a plurality of polygons. The object 300 refers to any virtual object that can be placed in a virtual three-dimensional space, such as a living thing such as a human being or an animal, or a building, a car, or another inanimate object. The virtual three-dimensional space is expressed by a world coordinate system defined by three axes (XYZ) orthogonal to each other. The object 300 is represented by an object coordinate system that is different from the world coordinate system, for example. The light source 302 is disposed at an arbitrary position in the virtual three-dimensional space. This light source 302 is, for example, an infinite light source. The position, direction, and intensity of the light source 302 are expressed by a light vector L. In the present embodiment, the length of the light vector L (in other words, the light intensity) is normalized to 1. The viewpoint (virtual camera) 304 is defined by the viewpoint position (coordinates in the world coordinate system) and the line-of-sight direction, and is represented by a camera vector C.

  Next, the contents of image processing executed by the game device of the present embodiment will be described using a flowchart and the like. The overall image processing flow of the present embodiment includes an object 300, a viewpoint 304, and a light source 302 (see FIG. 2), and rendering processing (coordinate conversion, clipping, perspective projection conversion, hidden surface removal, shading, shadowing). , Texture mapping, etc.), and the following processing relating to the canvas representation is performed. Note that the processing described below can change the processing order or perform each processing in parallel as long as the results do not contradict each other.

  FIG. 3 is a flowchart showing a flow of image processing executed by the game device of the first embodiment.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S10).

  The CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S11). The position of the viewpoint is set, for example, at a certain distance behind the object operated by the player. The position of the light source is fixed at a predetermined position, for example, or moves with time. The GPU 16 performs each process (rendering process) such as coordinate conversion, clipping, perspective projection conversion, hidden surface removal, etc., corresponding to each setting of the light source and the viewpoint. Thereby, an image obtained by perspective projection of the virtual three-dimensional space in which the object is arranged on the perspective projection plane is obtained. In the present embodiment, this image data is referred to as “basic image data”. The basic image data is stored in a frame buffer (first storage area) set in the graphic memory 17. FIG. 4 is a diagram schematically illustrating an example of basic image data. The basic image data shown in FIG. 4 includes a person image 400, a building image 402, a tree image 404, and a distant view image 406. Note that texture mapping is appropriately performed on each object (person, building, tree, distant view), but the expression is omitted here for convenience of explanation.

  Next, the GPU 16 sets a density map based on the data read from the storage medium 12 (step S12). The density map is data indicating density values associated with at least a part of the basic image data. The set density map is stored in a texture buffer (second storage area) set in the graphic memory 17.

  FIG. 5 is a diagram visually representing the contents of the density map. In FIG. 5, an annular region 410 provided in association with the outer edge side of the basic image data is shown in color. In this example, the density map shows density values associated with the annular area 410. Specifically, the density value is set within a numerical range of 0.0 to 1.0, for example. A density value of 0.0 is non-transparent (opaque), a density value of 1.0 is fully transmissive (transparent), and a middle part thereof is partially transmissive (semi-transparent). The density value is set for each pixel, for example. In the region colored in FIG. 5, this density value may be set to a constant value for all pixels, or may be set to a different value depending on the position of the pixel. In the storage medium 12, for example, two-dimensional data having the same size as the basic image data and in which a density value of 0.0 to 1.0 is set for each pixel is stored in advance. In this case, for an uncolored area 412 (area shown in white) inside the colored annular area 410 in FIG. 5, for example, the density value of each pixel in this area is set to 0.0. The By reading out such two-dimensional data, a density map as shown in FIG. 5 can be set.

  Next, the GPU 16 reads texture data from the storage medium 12 (step S13). FIG. 6 is a diagram for explaining an example of texture data. The texture data is image data including an arbitrary pattern. In the present embodiment, the texture data includes an image suitable for expressing a canvas pattern. For example, as shown in the figure, the image includes a pattern imitating a texture.

  Next, the GPU 16 generates two-dimensional image data by synthesizing the texture data read in step S13 with the basic image data at a ratio corresponding to the density value set by the density map set in step S12 ( Step S14). The generated two-dimensional image data is stored in a frame buffer set in the graphic memory 17.

  FIG. 7 is a diagram for explaining the state of the texture synthesized at a rate according to the density value. For example, if the density value is 0.5, “combine at a ratio according to the density value” means that both are mixed in the annular area 410 at a ratio of 50% texture data and 50% basic image data. It means that In this case, as shown in FIG. 7, the texture has a density value lower than the original density value (see FIG. 6). FIG. 8 shows a state in which texture data and basic image data are combined in this way. Texture data is synthesized in the annular region 410 at the periphery of the basic image data. The basic image is transmitted at a rate corresponding to the density value, and the texture is also translucent. If it is desired to display the texture darker, the density value may be close to 1.0. Thereby, since the degree of transmission of the basic image is reduced and the texture is displayed darker, the unpainted atmosphere can be more emphasized. When the density value is 1.0, the texture data is mixed at a ratio of 100% and the basic image data is 0%. As a result, the basic image is not transmitted and only the texture is displayed. become. In that case, the unpainted feeling in the annular region 410 is most emphasized. On the other hand, when it is desired to display the texture lighter, the density value may be close to 0.0. Thereby, the degree of transmission of the basic image is increased and the texture is displayed lighter, so that the unpainted atmosphere is weakened. That is, by appropriately setting the density value, the mixing ratio of the texture data including the canvas to the basic image data can be controlled, and the unpainted feeling can be freely controlled. Further, by setting the density value finely for each pixel instead of a constant value, it is possible to express the feeling of unpainted more delicately. In addition, by repeating the process shown in FIG. 3 at every predetermined timing, it is possible to generate a moving image in which the feeling of unpainted changes at any time according to each scene.

  In the present embodiment, the above-described annular area is given as an example of “part of the area in the basic image data”, but the method of setting the area is not limited to this. Further, the patterns included in the texture data shown in FIG. 6 are merely examples, and are not limited thereto.

(Second Embodiment)
A second embodiment according to the present invention will be described. The configuration of the game device according to the present embodiment (see FIG. 1), the relationship between the objects arranged in the virtual three-dimensional space, the light source, the viewpoint (see FIG. 2), and the overall flow of image processing (rendering processing) are described above. Since it is the same as that of the case of 1st Embodiment, description is abbreviate | omitted here. Hereinafter, processing relating to the expression of the canvas will be described. Note that the processing described below can change the processing order or perform each processing in parallel as long as the results do not contradict each other.

  FIG. 9 is a flowchart showing a flow of image processing executed by the game device of the second embodiment. Note that the description overlapping with the first embodiment is omitted as appropriate.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S20).

  The CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S21). Details of the processing in step S21 are the same as those in step S11 in the first embodiment described above. The basic image data (see FIG. 4) obtained here is stored in a frame buffer (first storage area) set in the graphic memory 17.

  Next, the CPU 10 arranges the translucent model associated with the density value in the virtual three-dimensional space based on the data read from the system memory 11 (step S22). FIG. 10 is a schematic diagram for explaining the processing content of step S22. As described above, the translucent model 306 is arranged in the virtual three-dimensional space in which the object 300, the light source 302, and the viewpoint 304 are set. This translucent model is configured by using, for example, one or several polygons. For each polygon, it is possible to set information of each color of R, G, and B and an α value (alpha value) as additional information. In the present embodiment, a density value is set as an α value that is additional information. The density value is set within a numerical range of 0.0 to 1.0, for example. A density value of 0.0 is non-transparent (opaque), a density value of 1.0 is fully transmissive (transparent), and a middle part thereof is partially transmissive (semi-transparent). By using the α value, it is possible to prepare a translucent model in which density values are associated. Note that the method using the α value is merely an example of a method for associating the density value with the semi-transparent model.

  Here, as shown in FIG. 10, the position of the translucent model 306 can be changed and set at any time in conjunction with a predetermined processing timing (for example, each frame in moving image generation). Thereby, for example, the state when the wind is blowing can be expressed by the canvas. An example of the image will be described later.

  Next, the GPU 16 sets a density map by rendering the translucent model arranged in the virtual three-dimensional space in step S22 (step S23). FIG. 11 is a visual representation of the density map set in step S23. In FIG. 11, a density map is set in a region represented by coloring. Specifically, the rendering defines a partial area 414 (in the illustrated example, an elliptical area) of the basic image data corresponding to the shape of the translucent model, and corresponds to this partial area. The assigned density value is specified. The set density map is stored in a texture buffer (second storage area) set in the graphic memory 17.

  Next, the GPU 16 reads texture data from the storage medium 12 (step S24). An example of the texture data is as shown in FIG.

  Next, the GPU 16 generates two-dimensional image data by combining the texture data read in step S24 with the basic image data at a ratio corresponding to the density value set by the density map set in step S23 ( Step S25). The generated two-dimensional image data is stored in a frame buffer set in the graphic memory 17.

  FIG. 12 is a diagram illustrating a state in which texture data and basic image data are synthesized at a ratio according to the density value. A texture is synthesized in a partial region 414 near the center of the basic image data. The basic image is transmitted at a rate corresponding to the density value, and the texture is also translucent. If it is desired to display the texture darker, the density value may be close to 1.0. Thereby, since the degree of transmission of the basic image is reduced and the texture is displayed darker, the unpainted atmosphere can be more emphasized. When the density value is 1.0, the texture data is mixed at a ratio of 100% and the basic image data is 0%. As a result, the basic image is not transmitted and only the texture is displayed. become. In that case, the unpainted feeling in the partial region 414 is most emphasized. On the other hand, when it is desired to display the texture lighter, the density value may be close to 0.0. Thereby, the degree of transmission of the basic image is increased and the texture is displayed lighter, so that the unpainted atmosphere is weakened. That is, by appropriately setting the density value, the mixing ratio of the texture data including the canvas to the basic image data can be controlled, and the unpainted feeling can be freely controlled. Further, by repeating the processing shown in FIG. 9 at every predetermined timing, it is possible to generate a moving image in which the feeling of unpainted changes at any time according to each scene.

  FIG. 13 is a diagram for explaining a display image when the position of the translucent model is moved as needed. As shown in FIG. 13, by reading from the system memory 11 or the storage medium 12 data that changes the position coordinates and density values of the translucent model in the virtual three-dimensional space as needed, the movement and density of the unpainted part in the moving image It is possible to express changes. This expression is suitable for representing, for example, how the wind flows.

  Note that the first process (FIG. 3; step S13) in the first embodiment and the second process (FIG. 9; steps S22 and S23) in the second embodiment are executed together, thereby both. An expression having both effects is possible (see FIG. 14).

(Third embodiment)
A third embodiment according to the present invention will be described. The configuration of the game device according to the present embodiment (see FIG. 1), the relationship between the objects arranged in the virtual three-dimensional space, the light source, the viewpoint (see FIG. 2), and the overall flow of image processing (rendering processing) are described above. Since it is the same as that of the case of 1st Embodiment, description is abbreviate | omitted here. Hereinafter, processing relating to the expression of the canvas will be described. Note that the processing described below can change the processing order or perform each processing in parallel as long as the results do not contradict each other.

  FIG. 15 is a flowchart illustrating a flow of image processing executed by the game device of the third embodiment. In addition, about the matter which overlaps with said each embodiment, description is abbreviate | omitted suitably.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S30).

  Further, the CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S31). Details of the processing in step S31 are the same as those in step S11 in the first embodiment described above. The basic image data (see FIG. 4) obtained here is stored in a frame buffer (first storage area) set in the graphic memory 17.

  Next, the GPU 16 calculates a fog value corresponding to the distance between the viewpoint position (camera position; see FIG. 2) and the object (step S32). More specifically, for example, the distance between the vertexes of the polygons forming each object and the viewpoint is calculated, and the fog value is calculated according to the calculated distance. Here, “fog” represents (simulates) fog in a virtual three-dimensional space, and more specifically represents the transparency of the space.

The fog value will be described with reference to FIG. The fog value is a parameter having a numerical value range of 0.0 to 1.0, for example. As the distance between the object and the viewpoint is shorter, the fog value becomes larger. When the fog value = 1.0, the fog is not applied at all. That is, the transparency is increased. Conversely, the fog value decreases as the distance between the object and the viewpoint increases, and when the fog value = 0.0, the fog is completely applied. That is, the transparency is lowered. In the example shown in FIG. 16A, when the distance is smaller than a certain threshold value L _th , the fog value is uniformly 1.0, and when the distance is greater than or equal to the threshold value L _th , the distance is long. As a result, the fog value decreases, and when a certain distance is reached, the fog value = 0.0. At this time, the relationship between the distance and the fog value changes linearly in FIG. 16A, but may also change nonlinearly as shown in FIGS. 16B and 16C. For example, in the example shown in FIG. 16B, the fog value decreases relatively slowly as the distance increases, and the fog value decreases abruptly when the distance increases to some extent. In the example shown in FIG. 16C, the fog value decreases relatively rapidly as the distance increases, and the degree of decrease in the fog value becomes milder as the distance increases to some extent. Note that the threshold value L _th for the distance is an arbitrary matter and need not be set. By setting the threshold value L _th , it is possible to prevent fog from being applied to an object (for example, a central drawing target such as a human character) that is close to a certain point of view.

  Next, the GPU 16 sets a density map based on the fog value calculated in step S32 (step S33). In the present embodiment, a value obtained by subtracting the fog value calculated in step S32 from 1.0 (1.0−fog value) is used as the density value. Note that the fog value may be appropriately adjusted to obtain the density value, such as by multiplying a predetermined constant. The density map set based on the fog value is stored in a texture buffer (second storage area) set in the graphic memory 17.

  FIG. 17 is a visual representation of the density map set in step S33. In FIG. 17, a density map is set in a region represented by coloring in a gray scale. This means that the darker the region, the higher the density value.

  Next, the GPU 16 reads texture data from the storage medium 12 (step S34). An example of the texture data is as shown in FIG.

  Next, the GPU 16 generates two-dimensional image data by combining the texture data read in step S34 with the basic image data at a ratio corresponding to the density value set by the density map set in step S33 ( Step S35). The generated two-dimensional image data is stored in a frame buffer set in the graphic memory 17.

  FIG. 18 is a diagram showing a state in which texture data and basic image data are synthesized at a ratio according to the density value. A fog value is calculated according to the distance between each object (person, building, tree, distant view) and viewpoint, and a density map is set based on the calculated fog value, so that a person image 400, a building image 402, a tree image 404, For each distant view image 406, the basic image is transmitted at a rate corresponding to the density value, and the texture is also translucent. Images that correspond to objects that are farther from the viewpoint have a higher degree of texture transparency, that is, the texture appears to be darker (see, for example, the distant view image 406), and images that correspond to objects that are closer to the viewpoint are more textured. It can be seen that the degree of transmission is small, that is, the texture looks thinner (see, for example, the person image 400). In this way, by setting the density map using the fog value, it is possible to control the mixing ratio of the texture data including the canvas to the basic image data according to the distance from the viewpoint and produce a feeling of unpainted color. it can. This is an expression that matches the general tendency that even in actual watercolor paintings, the closer the image is, the more delicate it is expressed, so there is less feeling of unpainted, and the more distant the image, the more unpainted feeling is. . In addition, by repeating the process shown in FIG. 15 at predetermined timings, it is possible to generate a moving image in which the feeling of unpainted changes at any time according to each scene.

(Fourth embodiment)
A fourth embodiment according to the present invention will be described. The configuration of the game device according to the present embodiment (see FIG. 1), and the relationship between objects, light sources, and viewpoints arranged in the virtual three-dimensional space (see FIG. 2) The overall flow of image processing (rendering processing) is the same as in the case of the first embodiment described above, and therefore description thereof is omitted here. Hereinafter, processing relating to the expression of the canvas will be described. Note that the processing described below can change the processing order or perform each processing in parallel as long as the results do not contradict each other.

  FIG. 19 is a flowchart illustrating a flow of image processing executed by the game device of the fourth embodiment. In addition, about the matter which overlaps with said each embodiment, description is abbreviate | omitted suitably.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S40).

  In addition, the CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S41). Details of the processing in step S41 are the same as those in step S11 in the first embodiment described above. The basic image data (see FIG. 4) obtained here is stored in a frame buffer (first storage area) set in the graphic memory 17.

  Next, the GPU 16 calculates an inner product value between the camera vector C (see FIG. 2) and the normal line of each polygon forming the object (step S42).

  Here, the relationship between each polygon forming the object and the camera vector will be described using the conceptual diagram shown in FIG. In FIG. 20, a single polygon 306 is shown to represent a plurality of polygons forming the object 300. The polygon 306 is a triangular piece having three vertices as shown. The polygon may be another polygon (for example, a quadrangle). A normal vector N is set at each vertex of the polygon 306. These normal vectors N are normalized to 1 in length. Note that these normal vectors N may be set at locations other than the vertices of the polygon, for example, arbitrary points on a plane defined by the vertices. In this embodiment, the inner product value of each normal vector N and light vector C is used as a parameter. Since the normal vector N and the camera vector C are both normalized to 1, this inner product value is cos θ, which is the cosine of the angle θ formed by them, and the value falls within the range of −1 to +1.

  Next, the GPU 16 sets a density map based on the inner product value calculated in step S42 (step S43). In the present embodiment, predetermined data conversion is performed on the inner product value, and the value after the data conversion is used as the density value. “Data conversion” generally means that the density value increases as the angle θ between the normal vector N and the camera vector C increases (that is, the inner product value decreases), and when θ = 90 ° (that is, The inner product value is converted according to a certain rule so that the density value becomes the maximum value when the inner product value is 0). The density map set based on the inner product value is stored in a texture buffer (second storage area) set in the graphic memory 17.

  FIG. 21 is a diagram illustrating a specific example of data conversion. As shown in FIG. 21, the density value is 1.0 when the inner product value is 0, and the density value is 0.0 when the inner product value is a predetermined upper limit value (0.15 in the illustrated example). In this example, the above-described data conversion can be realized by performing interpolation such that the density value changes linearly (between 0 and 0.15). At this time, the density value is uniformly set to 0.0 for a portion where the inner product value exceeds a predetermined value. Note that nonlinear interpolation may be performed instead of such linear interpolation. By adjusting the upper limit value, it is possible to freely determine the size of the range in which the density value is greater than 0.0 (see FIG. 22 described later). Note that this upper limit is not essential for data conversion. As simpler data conversion, for example, an operation of (1.0−inner product value) = density value may be employed.

FIG. 22 is a visual representation of the density map set in step S43. In FIG. 22, a density map is set in a region represented by being colored in gray scale. Although not shown in the figure, the angle θ between the normal vector N and the camera vector C approaches 90 ° on the outside of the object and the like, and the density value increases as such a position. Also, the above-described upper limit is set. By converting the inner product value into data, an area having a density value greater than 0.0 can be limited to a location where the angle θ formed by the camera vector C and the normal vector N is relatively large.

  Next, the GPU 16 reads texture data from the storage medium 12 (step S44). An example of the texture data is as shown in FIG.

  Next, the GPU 16 synthesizes the texture data read in step S44 with the basic image data at a ratio corresponding to the density value set by the density map set in step S33, thereby generating two-dimensional image data ( Step S45). The generated two-dimensional image data is stored in a frame buffer set in the graphic memory 17.

  FIG. 23 is a diagram showing a state in which texture data and basic image data are synthesized at a ratio corresponding to the density value. Since the density map is set based on the inner product value of the polygon normal vector and the camera vector of each object (person, building, tree, distant view), each of the person image 400, the building image 402, and the tree image 404 is set. The basic image is transmitted at a rate corresponding to the density value, and the texture is also translucent. The greater the angle between the normal vector and the camera vector (that is, the smaller the inner product value), the greater the degree of transmission of the texture, that is, the state where the texture appears darker. Thereby, the outer side (outer edge) of each object is more emphasized. In this way, by setting the density map using the inner product value, the mixing ratio of the texture data including the canvas to the basic image data is controlled according to the angle formed by the camera vector (line of sight) and the object surface, An unpainted feeling can be produced. This is an expression that matches a general tendency that the feeling of unpainted ink increases toward the outside (outer edge) of the object to be drawn even in an actual watercolor painting or the like. In addition, by repeating the process shown in FIG. 19 at every predetermined timing, it is possible to generate a moving image in which the feeling of unpainted changes at any time according to each scene.

(Fifth embodiment)
The image processing described in the first to fourth embodiments described above can also be used in combination. The details will be described below. Note that the configuration of the game device according to the present embodiment (see FIG. 1), the relationship between the objects arranged in the virtual three-dimensional space, the light source, the viewpoint (see FIG. 2), and the overall flow of image processing (rendering processing). Since it is the same as that of each above-mentioned embodiment, description is abbreviate | omitted here. In addition, the processing described below can change the processing order or perform each processing in parallel as long as no contradiction arises in the results.

  FIG. 24 is a flowchart illustrating a flow of image processing executed by the game device of the fifth embodiment. In addition, about the matter which overlaps with said each embodiment, description is abbreviate | omitted suitably.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S50).

  Further, the CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S51). Details of the processing in step S51 are the same as those in step S11 in the first embodiment. The basic image data (see FIG. 4) obtained here is stored in a frame buffer (first storage area) set in the graphic memory 17.

  Next, the GPU 16 performs the first process in the first embodiment (see FIG. 3; see step S13), the second process in the second embodiment (see FIG. 9; see steps S22 and 23), and the third implementation. Each of the third process in the embodiment (see FIG. 3; steps S32 and 33) and the fourth process in the fourth embodiment (see FIG. 3; steps S42 and 43) is executed (step S52). Details of each of the first process to the fourth process are as described above, and a detailed description thereof will be omitted. Briefly, the first process is a process for setting a density map using fixed data prepared in advance, the second process is a process for setting a density map using a semi-transparent model, and the third process is a fog process. A process for setting a density map using a value and a fourth process are processes for setting a density map using an inner product value of a camera vector and a polygon normal.

  In step S52, at least any two of the first process, the second process, the third process, and the fourth process may be performed. It is arbitrary which process is combined.

  Next, the GPU 16 synthesizes the density map set by each of the first process to the fourth process (if any process is selectively executed, the selected process) (step S53). . Specifically, the density values obtained by each process are compared for each pixel, and the highest density value is selected for each pixel. FIG. 25 is a visualization of the density map (synthetic density map) obtained by this synthesis process.

  Note that the method of synthesizing the density map in step S53 is not limited to the above. For example, the density value obtained by each process of the first process to the fourth process may be compared for each pixel, and the lowest density value may be selected for each pixel, or the first value may be selected for each pixel. You may average the density value by each of a process-4th process. Further, the density map obtained by any of the processes may be used with priority over other density maps. For example, it is preferable to use the density map of the first process with priority.

  Next, the GPU 16 reads texture data from the storage medium 12 (step S54). An example of the texture data is as shown in FIG.

  Next, the GPU 16 generates two-dimensional image data by combining the texture data read in step S54 with the basic image data at a ratio corresponding to the density value set by the combined density map obtained in step S53. (Step S55). The generated two-dimensional image data is stored in a frame buffer set in the graphic memory 17.

  FIG. 26 is a diagram showing a state in which texture data and basic image data are synthesized at a ratio corresponding to the density value. It can be seen that the results of the first process to the fourth process are combined.

(Modified Example)
In addition, this invention is not limited to the content of each embodiment mentioned above, A various deformation | transformation implementation is possible within the scope of the summary of this invention. For example, in the above-described embodiment, a game device is realized by causing a computer including hardware such as a CPU to execute a predetermined program. However, each functional block provided in the game device is dedicated hardware or the like. It may be realized using.

  In the above description, the game apparatus is taken as an example, and the embodiments of the image processing apparatus, the image processing method, and the image processing program according to the present invention have been described. However, the scope of the present invention is not limited to this. For example, the present invention can also be applied to a simulator device or the like that reproduces various real world experiences (for example, driving operations) in a pseudo manner.

(Supplementary note: technical idea)
A part of the technical idea according to the above-described embodiment will be additionally described below.

  A program according to the present invention is a program that is executed by an image processing apparatus including a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane. And (a) arranging a viewpoint in the virtual three-dimensional space, generating perspective image data by performing perspective projection on the perspective projection plane set corresponding to the viewpoint, and generating the basic image Storing data in the storage means; and (b) setting a density map indicating density values associated with a partial area of the basic image data, and storing the density map in the storage means; (C) reading texture data from the storage means; and (d) the texture data at a ratio corresponding to the density value set by the density map. Characterized in that to execute the steps of generating the two-dimensional image data by combining the data.

  Preferably, in (b), data defining the partial area and designating the density value of the partial area is read from the storage means, and the density map is calculated based on the read data. Set.

  Preferably, (b) defines the partial area by rendering the translucent model by arranging the translucent model associated with the density value in the virtual three-dimensional space and rendering the translucent model. The density map for designating the density value in a partial area is set.

  Preferably, the texture data includes a canvas pattern image. The “canvas pattern” refers to a general pattern that can simulate the surface of a canvas (canvas) used for a watercolor painting or the like, for example, a pattern imitating the surface of linen or the like.

  The computer-readable recording medium according to the present invention is a recording medium on which the program according to the present invention is recorded. The present invention can also be expressed as an image processing apparatus and an image processing method as follows.

  An image processing apparatus according to the present invention is an image processing apparatus that includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane, The computing means (a) arranges a viewpoint in the virtual three-dimensional space, generates perspective image data by perspective projection on the perspective projection plane set corresponding to the viewpoint, and generates the basic image data Means for storing in the storage means; (b) means for setting a density map indicating density values associated with a partial area of the basic image data; and means for storing the density map in the storage means; and (c) texture. Means for reading out data from the storage means; and (d) combining the texture data with the basic image data at a ratio corresponding to the density value set by the density map. It means for generating over data, characterized in that function as each.

  In an image processing method according to the present invention, two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane in an image processing apparatus including a storage unit and a calculation unit. In the image processing method to be generated, the arithmetic means (a) arranges a viewpoint in the virtual three-dimensional space, and performs perspective projection on the perspective projection plane set corresponding to the viewpoint to perform basic image data. And (b) setting a density map indicating density values associated with a partial area of the basic image data, and storing the density map in the memory (C) reading the texture data from the storage means; (d) dividing the texture data according to the density value set by the density map. In and executes each step, generating the two-dimensional image data by combining said basic image data.

It is a block diagram which shows the structure of the game device of one Embodiment. It is the conceptual diagram shown about each of the object (virtual object) arrange | positioned in virtual three-dimensional space, a light source, and a viewpoint. It is a flowchart which shows the flow of the image process performed by the game device of 1st Embodiment. It is a figure which shows an example of basic image data typically. It is the figure which expressed the contents of the density map visually. It is a figure explaining an example of texture data. It is a figure explaining the mode of the texture synthesize | combined in the ratio according to a density value. It is the figure which showed a mode that the texture data and the basic image data were synthesize | combined. It is a flowchart which shows the flow of the image processing performed by the game device of 2nd Embodiment. It is a schematic diagram explaining the processing content of step S22. This is a visual representation of the density map set in step S23. It is the figure which showed a mode that the texture data and the basic image data were synthesize | combined in the ratio according to a density value. It is a figure explaining the display image at the time of moving the position of a semi-transparent model at any time. It is an example of the image which has the effect by the 1st process in 1st Embodiment, and the 2nd process in 2nd Embodiment. It is a flowchart which shows the flow of the image processing performed by the game device of 3rd Embodiment. It is a figure for demonstrating a fog value. This is a visual representation of the density map set in step S33. It is the figure which showed a mode that the texture data and the basic image data were synthesize | combined in the ratio according to a density value. It is a flowchart which shows the flow of the image processing performed by the game device of 4th Embodiment. It is a conceptual diagram explaining the relationship between each polygon which forms an object, and a camera vector. It is a figure explaining the specific example of the data conversion in step S43. This is a visual representation of the density map set in step S43. It is the figure which showed a mode that the texture data and the basic image data were synthesize | combined in the ratio according to a density value. It is a flowchart which shows the flow of the image processing performed by the game device of 5th Embodiment. It is the figure which visualized and showed the synthetic density map. It is the figure which showed a mode that the texture data and the basic image data were synthesize | combined in the ratio according to a density value.

Explanation of symbols

10 ... CPU
11 ... System memory 12 ... Storage medium 13 ... Bootrom 14 ... Bus arbiter 16 ... GPU
17 ... Graphic memory 18 ... Audio processor 19 ... Audio memory 20 ... Communication interface (I / F)
21 ... Peripheral interface

Claims (19)

A program that is executed by an image processing apparatus including a storage unit and a calculation unit and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane,
In the calculation means,
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit And steps to
(B) calculating a fog value representing the transparency of the virtual three-dimensional space according to the distance between the position of the viewpoint and the object arranged in the virtual three-dimensional space;
(C) setting a density map indicating a density value associated with the basic image data based on the fog value, and storing the density map in the storage unit;
(D) reading texture data from the storage means;
(E) generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
A program that executes In (b), when the distance between the viewpoint and the object is smaller than a predetermined threshold, the fog value is set to a constant value.
The program according to claim 1. (C) sets the density map using the fog value as the density value as it is.
The program according to claim 1. A program that is executed by an image processing apparatus including a storage unit and a calculation unit and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane,
In the calculation means,
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit And steps to
(B) calculating an inner product value of a camera vector indicating the direction of the viewpoint and a normal vector of a polygon of an object arranged in the virtual three-dimensional space;
(C) setting a density map indicating a density value associated with the basic image data based on the inner product value, and storing the density map in the storage unit;
(D) reading texture data from the storage means;
(E) generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
A program that executes In (c), with respect to the inner product value, the smaller the inner product value is, the larger the density value is, and when the inner product value is 0, data conversion is performed so that the density value becomes the maximum value, Setting the density map based on the density value obtained by the data conversion;
The program according to claim 4. The texture data includes an image of a canvas pattern,
The program according to any one of claims 1 to 5.   A computer-readable recording medium on which the program according to any one of claims 1 to 6 is recorded. An image processing apparatus that includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane,
The computing means is
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit Means to
(B) means for calculating a fog value representing the transparency of the virtual three-dimensional space according to the distance between the position of the viewpoint and the object arranged in the virtual three-dimensional space;
(C) means for setting a density map indicating density values associated with the basic image data based on the fog value, and storing the density map in the storage means;
(D) means for reading texture data from the storage means;
(E) means for generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
An image processing apparatus that functions as each of the above. In (b), when the distance between the viewpoint and the object is smaller than a predetermined threshold, the fog value is set to a constant value.
The image processing apparatus according to claim 8. (C) sets the density map using the fog value as the density value as it is.
The image processing apparatus according to claim 8. An image processing apparatus that includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space on a predetermined perspective projection plane,
The computing means is
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit Means to
(B) means for calculating an inner product value between a camera vector indicating the direction of the viewpoint and a normal vector of a polygon of an object arranged in the virtual three-dimensional space;
(C) means for setting a density map indicating density values associated with the basic image data based on the inner product value, and storing the density map in the storage means;
(D) means for reading texture data from the storage means;
(E) means for generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
An image processing apparatus that functions as each of the above. In (c), with respect to the inner product value, the smaller the inner product value is, the larger the density value is, and when the inner product value is 0, data conversion is performed so that the density value becomes the maximum value, Setting the density map based on the density value obtained by the data conversion;
The image processing apparatus according to claim 11. The texture data includes an image of a canvas pattern,
The image processing apparatus according to claim 8. In an image processing apparatus including a storage unit and a calculation unit, an image processing method for generating two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane,
The computing means is
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit And steps to
(B) calculating a fog value representing the transparency of the virtual three-dimensional space according to the distance between the position of the viewpoint and the object arranged in the virtual three-dimensional space;
(C) setting a density map indicating a density value associated with the basic image data based on the fog value, and storing the density map in the storage unit;
(D) reading texture data from the storage means;
(E) generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
An image processing method for executing each of the above. In (b), when the distance between the viewpoint and the object is smaller than a predetermined threshold, the fog value is set to a constant value.
The image processing method according to claim 14. (C) sets the density map using the fog value as the density value as it is.
The image processing method according to claim 14. In an image processing apparatus including a storage unit and a calculation unit, an image processing method for generating two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane,
The computing means is
(A) A viewpoint is arranged in the virtual three-dimensional space, perspective projection is performed on the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit And steps to
(B) calculating an inner product value of a camera vector indicating the direction of the viewpoint and a normal vector of a polygon of an object arranged in the virtual three-dimensional space;
(C) setting a density map indicating a density value associated with the basic image data based on the inner product value, and storing the density map in the storage unit;
(D) reading texture data from the storage means;
(E) generating the two-dimensional image data by combining the texture data with the basic image data at a ratio according to the density value set by the density map;
An image processing method for executing each of the above. In (c), with respect to the inner product value, the smaller the inner product value is, the larger the density value is, and when the inner product value is 0, data conversion is performed so that the density value becomes the maximum value, Setting the density map based on the density value obtained by the data conversion;
The image processing method according to claim 17. The texture data includes an image of a canvas pattern,
The image processing method according to claim 14.