JP4028055B2 - Image generating apparatus and information storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image generation apparatus and an information storage medium that generate an image using texture mapping.
[0002]
[Background Art and Problems to be Solved by the Invention]
Conventionally, various types of image generation devices such as game devices and simulators are known. In such an image generating apparatus, how to improve the quality of an image has become a major technical issue in order to realize so-called virtual reality. A technique called translucent processing is known as one of such image quality enhancement techniques.
[0003]
In the translucent process, the color of each pixel (dot) is obtained by performing a blend process for blending the color of the background object and the color of the translucent object and a filter process for filtering the color of the background object. By performing translucent processing, translucent expression is possible, and the reality of the image can be increased.
[0004]
However, in the semi-transparent processing, calculation processing such as blend processing and filter processing has to be performed for each pixel. Therefore, there is a problem that the processing load on the image generation apparatus is heavy and the speeding up of the processing of the image generation apparatus is hindered.
[0005]
On the other hand, pseudo-translucent expression is possible only by blend processing and filter processing, but real translucent expression faithful to the real world cannot be achieved. For this reason, the realization of virtual reality has been insufficient with the conventional translucent processing methods.
[0006]
Further, in an image generation apparatus that does not have a hardware function for realizing translucent processing, there is a problem that translucent expression itself is impossible.
[0007]
In order to represent a more realistic image, it is desirable to be able to express light refraction and reflection. However, if such an expression is to be realized, the hardware of the image generation device becomes larger and more complicated, This increases the cost of the image generation apparatus.
[0008]
The present invention has been made to achieve the above technical problem, and an object of the present invention is to provide an image generation apparatus and an information storage medium capable of more realistic image expression with a small processing load. Is to provide.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides an image generation apparatus that generates an image using texture mapping, and includes a first texture and a second texture having the first texture as an original image. Means for storing, and means for mapping the first texture to the first object and mapping the second texture to the second object arranged to overlap the first object And an image obtained when an object having a material property different from that of the object is superimposed on the object.
[0010]
According to the present invention, the second texture having the first texture mapped to the first object as the original image is mapped to the second object arranged to overlap the first object. Then, an image obtained when an object having a material property different from that of the object is superimposed on the object is generated. That is, first and second textures for generating such an image are prepared. As a result, for example, an image or the like that can be seen when a translucent object is placed on a background object can be generated without significantly increasing the processing load of the image generation apparatus. In addition, by making the first and second texture images high-definition and high-quality, it is possible to generate a realistic image that cannot be obtained by a normal translucent process or the like.
[0011]
The present invention also relates to an image generation apparatus that generates an image using texture mapping, the first texture and a second texture having the first texture as an original image, a first texture, Means for mapping the first texture to a second object and means for mapping the second texture to a second object arranged to overlap the first object, An image obtained when the property is partially changed is generated.
[0012]
According to the present invention, the second texture having the first texture as the original image is mapped to the second object, and an image obtained when the material property of the object is partially changed is generated. That is, first and second textures for generating such an image are prepared. As a result, for example, an image that can be seen when the color, brightness, translucency, reflectance, and refractive index of the background object are partially changed can be generated without increasing the processing load of the image generating apparatus so much. become. In addition, by making the first and second texture images high-definition and high-quality, it is possible to generate a realistic image that cannot be obtained by normal processing.
[0013]
In the invention, it is preferable that the material property is at least one of color, luminance, translucency, reflectance, and refractive index. As described above, various material properties can be considered. However, the material property in the present invention is not limited to these.
[0014]
The present invention is characterized in that at least one of the position and shape of the second object is changed in real time. In this way, it is possible to obtain various images such as a semi-transparent object moving on the background object or changing its shape.
[0015]
Further, the present invention obtains texture coordinates to be given to the vertices of the second object based on the positions of the vertices of the first and second objects, and assigns the second object to the second object based on the texture coordinates. It is characterized by mapping a texture. By doing in this way, the texture coordinate used when reading a 2nd texture from a memory | storage means can be obtained by a simple process.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following, a case where an object is composed of one or a plurality of polygons will be described as an example. However, the present invention can be applied to various objects such as an object composed of a primitive surface such as a curved surface other than a polygon.
[0017]
First, the principle of this embodiment will be described. Now, as shown in FIG. 1, consider an image that appears when a translucent object 302 is superimposed on a background object 300 on which a letter A is drawn. In the past, a method called translucent processing has been employed to generate such an image. For example, in the blending process which is one of the translucent processes, an arithmetic process such as the following expression (1) is performed.
R _Q = OP ₁ × R _T + (1−OP ₁ ) × R _X
G _Q = OP ₁ × G _T + (1−OP ₁ ) × G _X (1)
B _Q = OP ₁ × B _T + (1−OP ₁ ) × B _X
Here, OP ₁ is an opacity (opacity) in the blending process, R _T, G _T , and B _T are color data of the translucent object, R _X , G _X , and B _X are color data of the background object, R _Q , G _Q and B _Q are color data obtained by translucent processing. Note that OP ₁ may be different for each of R, G, and B.
[0018]
In the filter process, which is one of the translucent processes, an arithmetic process such as the following expression (2) is performed.
R _Q = OP ₂ × F _R × R _X
G _Q = OP ₂ × F _G × G _X (2)
B _Q = OP ₂ × F _B × B _X
Here, OP ₂ is an opacity in the filtering process, and F _R , F _G , and F _B are filter coefficients of the translucent object.
[0019]
In the translucent processes such as the blend process and the filter process as described above, it is necessary to perform an arithmetic process as shown in the above equations (1) and (2) for each pixel. Therefore, there is a problem that the processing load on the image generating apparatus becomes excessive and the speeding up of the processing is hindered.
[0020]
In addition, in the arithmetic processing shown in the above formulas (1) and (2), pseudo-translucent expression is possible, but there is a problem that realistic translucent expression close to the real world cannot be performed.
[0021]
In order to solve such a problem, the image generation apparatus according to the present embodiment has the following characteristics. That is, as shown in FIG. 2, in the present embodiment, first, a first texture 20 and a second texture 22 using the first texture 20 as an original image are prepared in a texture space (U, V space). To do. More specifically, the first texture 20 represents an image of a background object on which the letter A is drawn. On the other hand, the second texture 22 represents an image that can be seen when a semi-transparent object overlaps the entire surface of the background object represented by the first texture 20. For example, when the color of the translucent object is blue, the second texture 22 represents an image in which the first texture 20 is entirely bluish.
[0022]
In the image generation apparatus according to the present embodiment, the first texture 20 is mapped to the first object 30 as shown in FIG. On the other hand, the second texture 22 is mapped to the second object 32 arranged so as to overlap the first object 30. The first and second objects 30 and 32 are constituted by at least one primitive surface (polygon, curved surface, etc.), for example.
[0023]
By performing texture mapping as described above, an image as shown in B1 of FIG. 2 can be obtained. In other words, an image that can be seen when a semi-transparent object (an object having a material property different from that of the background object) is superimposed on the background object can be generated without performing a semi-transparent process such as a blend process or a filter process. .
[0024]
In this case, the first and second textures 20 and 22 are created in advance by a workstation or the like having the ability to generate high-definition and high-quality images, and the texture storage unit (see 130 in FIG. 7) in the image generation apparatus. ) Is stored. Therefore, the image generation device does not need to generate the first and second textures 20 and 22 themselves, and the processing load on the image generation device is only the processing load required for mapping the first and second textures 20 and 22. It becomes. Therefore, the processing load can be greatly reduced as compared with translucent processing such as blend processing and filter processing as shown in the above formulas (1) and (2). Since the first and second textures 20 and 22 can be created by a workstation that can generate high-definition and high-quality images, the first and second textures 20 and 22 are compared to the case where images are generated by translucent processing such as blend processing and filter processing. Thus, a much more realistic image can be generated.
[0025]
In the above description, semi-transparency (transparency) has been described as an example of material properties. However, there are various other material properties such as color, brightness, reflectivity (specular reflection, diffuse reflection), and refractive index. Can think. That is, according to the present embodiment, it is possible to generate an image that is visible when an object having different material properties such as color, brightness, reflectance, translucency, and refractive index is superimposed on the background object.
[0026]
For example, FIG. 3 shows an example of an image that can be seen when an object having a refractive index different from that of the background object is superimposed on the background object. In general, expressing the refraction or reflection of light causes an increase in processing load on the image generation apparatus, an increase in hardware scale, and an increase in cost. On the other hand, in the present embodiment, an image as shown in FIG. 3 can be expressed simply by creating the first and second textures 20 and 22 in FIG. 2 in advance so as to express the refraction of light. it can. Therefore, a real image can be generated without increasing the processing load of the image generating apparatus so much.
[0027]
In the above, an example has been shown in which an image that is visible when an object having a material property different from that of the background object is superimposed on the background object is generated. However, according to the present embodiment, it is possible to generate an image that can be seen when the material property of the background object is partially changed.
[0028]
That is, in FIG. 4, the second texture 22 represents an image when the first texture 20 is the original image and the luminance of the first texture 20 is increased overall. Then, the first texture 20 is mapped to the first object 30, and the second texture 22 is mapped to the second object 32 arranged so as to overlap the first object 30. As a result, as shown in C1 of FIG. 4, an image obtained when the luminance (material property) of the background object is partially changed is generated. As a result, a real image can be generated without increasing the processing load of the image generating apparatus so much.
[0029]
Various material properties such as color, brightness, translucency, reflectance, and refractive index can be considered as material properties in this case.
[0030]
In FIG. 5A, the position of the second object 32 is changed on the first object 30 in real time. By doing so, as shown in FIG. 5B, it is possible to express that the translucent object moves in real time on the background object. That is, for example, an expression that an amoeba freely moves on a signboard is possible.
[0031]
In FIG. 6A, the shape of the second object 32 is changed on the first object 30 in real time. By doing so, as shown in FIG. 6B, it is possible to express that the shape of the translucent object changes in real time on the background object. That is, for example, an expression that the amoeba gradually becomes larger or smaller on the signboard is possible.
[0032]
In order to realize the expressions shown in FIGS. 5B and 6B using the above-described translucent processing such as blend processing and filter processing, the range to be subjected to the translucent processing must be changed in real time. I must. Therefore, the processing becomes complicated and the processing load increases. According to the present embodiment, it is possible to express as shown in FIGS. 5B and 6B only by changing the position and shape of the second object 32. Therefore, an unprecedented realistic video effect can be obtained with a small processing load.
[0033]
FIG. 7 shows an example of a functional block diagram of the image generation apparatus of the present embodiment.
[0034]
The processing unit 100 performs various processes for image generation. The function of the processing unit 100 can be realized by various hardware such as a CPU (CISC type, RISC type), a DSP, a custom (gate array, etc.) IC, and a memory.
[0035]
The information storage medium 190 stores programs and data. The function of the information storage medium 190 can be realized by hardware such as a CD-ROM, game cassette, IC card, MO, FD, DVD, hard disk, and memory. The processing unit 100 performs various processes based on the program and data from the information storage medium 190.
[0036]
The processing unit 100 includes an object space setting unit 110, a mapping unit 120, a texture storage unit 130, and an image generation unit 150.
[0037]
Here, the object space setting unit 110 performs processing for arranging objects in the object space. Taking a three-dimensional game as an example, a position or direction of a moving object such as a car is calculated in real time, or a process of arranging objects constituting a map on which the moving object moves is performed. In the present embodiment, the object space setting unit 110 performs processing for arranging the first and second objects 30 and 32 in FIG. 2 and processing for changing the position and shape of the second object 32 in real time.
[0038]
The mapping unit 120 performs a process for mapping a texture on the object placed in the object space by the object space setting unit 110. In the present embodiment, the mapping unit 120 maps the first texture 20 to the first object 30 in FIG. 2, and the second object 32 arranged so as to overlap the first object 30. On the other hand, a process for mapping the second texture 22 is performed.
[0039]
The mapping unit 120 includes a texture coordinate calculation unit 122. The texture coordinate calculation unit 122 performs processing for calculating texture coordinates U and V for designating a texture to be mapped to an object. More specifically, the texture coordinate calculation unit 122 performs a calculation process for obtaining texture coordinates to be given to the vertices of the second object 32 based on the positions of the vertices of the first and second objects 30 and 32, for example. .
[0040]
The texture storage unit 130 stores a texture to be mapped to an object. The first and second textures 20 and 22 in FIG. 2 are stored in the texture storage unit 130. The texture data is stored in the information storage medium 190 in the initial state, and is transferred from the information storage medium 190 to the texture storage unit 130 after the power is turned on.
[0041]
Further, the image generation unit 150 performs a process of generating an image including an image of the object to which the texture is mapped by the mapping unit 120. The image generated by the image generation unit 150 is displayed on the display unit 160.
[0042]
FIGS. 8A and 8B show examples of images generated by this embodiment. FIGS. 8A and 8B are images representing a state in which a wave strikes the coast. In order to express such an image, in this embodiment, first and second textures 20 and 22 as shown in FIG. 9 are prepared. The first texture 20 is a texture representing a rock, and the second texture 22 is a texture representing a rock in the water. These first and second textures 20 and 22 are mapped to the first and second objects 30 and 32 shown in FIGS. And the shape of the 2nd object 32 arrange | positioned so that it may overlap with the 1st object 30 is changed so that a wave may be represented. This makes it possible to realize a realistic expression of the coast where waves hit, with a small processing load.
[0043]
10A and 10B show other examples of images generated by this embodiment. FIGS. 10A and 10B are images representing a state in which a bomb is dropped on a city and the explosion range expands in real time. In this case, a texture representing the state of the city before the explosion is prepared as the first texture 20, and a texture representing the state of the city after the explosion is prepared as the second texture 22. Then, as shown in FIGS. 10A and 10B, the shape of the second object 32 arranged so as to overlap the first object 30 is changed so as to represent the expansion of the explosion range. As a result, a realistic expression of the destruction of the city by the bomb can be realized with a small processing load.
[0044]
Next, a detailed processing example of this embodiment will be described with reference to the flowchart of FIG.
[0045]
First, as shown in FIG. 12, the first and second objects 30 and 32 are arranged so that the second object 32 overlaps the first object 30 (step S1).
[0046]
Next, the first texture 20 is mapped to the first object 30 (step S2). Here, the first texture 20 mapped to the first object 30 is texture coordinates (Ua0, Va0), (Ua1, Va1), (Ua2) given to the vertices a0, a1, a2, a3 of the first object 30. , Va2), (Ua3, Va3).
[0047]
Next, texture coordinates (Ub0, Vb0), (Ub1, Vb1), (Ub2, Vb2), (Ub3, Vb3) to be given to the vertices b0, b1, b2, b3 of the second object 32 are calculated (step S3). ). These texture coordinates are used to read out the second texture 22 corresponding to the first texture 20 from the texture storage unit 130. More specifically, for example, the position (Xa0, Ya0), (Xa1, Ya1), (Xa2, Ya2), (Xa3, Ya3) of the vertex of the first object 30 and the position of the vertex of the second object Based on the positional relationship with (Xb0, Yb0), (Xb1, Yb1), (Xb2, Yb2), (Xb3, Yb3), texture coordinates (Ub0, Vb0), (Ub1, Vb1), (Ub2, Vb2) and (Ub3, Vb3) are calculated.
[0048]
Next, based on the calculated texture coordinates (Ub0, Vb0) to (Ub3, Vb3), the second texture 22 is mapped to the second object 32 (step S4).
[0049]
As described above, images as shown in B1 of FIG. 2 and C1 of FIG. 4 can be obtained.
[0050]
Next, an example of a hardware configuration capable of realizing the present embodiment will be described with reference to FIG. In the apparatus shown in the figure, a CPU 1000, a ROM 1002, a RAM 1004, an information storage medium 1006, a sound generation IC 1008, an image generation IC 1010, and I / O ports 1012, 1014 are connected to each other via a system bus 1016 so that data can be transmitted and received. A display 1018 is connected to the image generation IC 1010, a speaker 1020 is connected to the sound generation IC 1008, a control device 1022 is connected to the I / O port 1012, and a communication device 1024 is connected to the I / O port 1014. Has been.
[0051]
The information storage medium 1006 mainly stores programs, image data for expressing display objects, sound data, and the like. For example, a consumer game device uses a CD-ROM, game cassette, DVD, or the like as an information storage medium for storing a game program or the like. The arcade game machine uses a memory such as a ROM. In this case, the information storage medium 1006 is a ROM 1002.
[0052]
The control device 1022 corresponds to a game controller, an operation panel, and the like, and is a device for inputting a result of a determination made by the player in accordance with the progress of the game to the device main body.
[0053]
In accordance with a program stored in the information storage medium 1006, a system program stored in the ROM 1002 (such as device initialization information), a signal input by the control device 1022, the CPU 1000 controls the entire device and performs various data processing. . The RAM 1004 is a storage means used as a work area of the CPU 1000 and stores the given contents of the information storage medium 1006 and the ROM 1002 or the calculation result of the CPU 1000. In addition, a data structure (for example, a data structure of a texture or an object) having a logical configuration for realizing the present embodiment is constructed on this RAM or information storage medium.
[0054]
Further, this type of apparatus is provided with a sound generation IC 1008 and an image generation IC 1010 so that game sounds and game images can be suitably output. The sound generation IC 1008 is an integrated circuit that generates game sounds such as sound effects and background music based on information stored in the information storage medium 1006 and the ROM 1002, and the generated game sounds are output by the speaker 1020. The image generation IC 1010 is an integrated circuit that generates pixel information to be output to the display 1018 based on image information sent from the RAM 1004, the ROM 1002, the information storage medium 1006, and the like. As the display 1018, a so-called head mounted display (HMD) can be used.
[0055]
The communication device 1024 exchanges various types of information used inside the game device with the outside. The communication device 1024 is connected to other game devices to send and receive given information according to the game program, and to connect a communication line. It is used for sending and receiving information such as game programs.
[0056]
Various processes described with reference to FIGS. 1 to 10 and 12 include an information storage medium 1006 that stores a program for performing the process shown in the flowchart of FIG. 11, a CPU 1000 that operates according to the program, an image generation IC 1010, a sound This is realized by the generation IC 1008 or the like. The processing performed by the image generation IC 1010, the sound generation IC 1008, and the like may be performed by software using the CPU 1000 or a general-purpose DSP.
[0057]
FIG. 14A shows an example in which the present embodiment is applied to an arcade game machine. The player enjoys the game by operating the lever 1102, the button 1104, and the like while viewing the game image displayed on the display 1100. A CPU, an image generation IC, a sound generation IC, and the like are mounted on a system board 1106 built in the apparatus. Then, information for storing the first texture and the second texture having the first texture as the original image, the first texture is mapped to the first object, and the first object is mapped to the first object. Information for mapping the second texture to the second object arranged so as to overlap, and an image obtained when an object having a material property different from that of the object is superimposed on the object , Information for generating an image obtained when the material property of the object is partially changed, and the like are stored in a memory 1108 that is an information storage medium on the system board 1106. Hereinafter, these pieces of information are referred to as stored information. The stored information includes at least one of program code, image information, sound information, display object shape information, table data, list data, player information, and the like for performing the various processes described above.
[0058]
FIG. 14B shows an example in which the present embodiment is applied to a home game device. The player enjoys the game by operating the game controllers 1202 and 1204 while viewing the game image displayed on the display 1200. In this case, the stored information is stored in a CD-ROM 1206, IC cards 1208, 1209, etc., which are information storage media detachable from the main unit.
[0059]
FIG. 14C shows an example in which the present embodiment is applied to a game device including a host device 1300 and terminals 1304-1 to 1304-n connected to the host device 1300 via a communication line 1302. Show. In this case, the stored information is stored in an information storage medium 1306 such as a magnetic disk device, a magnetic tape device, or a memory that can be controlled by the host device 1300, for example. When the terminals 1304-1 to 1304-n have a CPU, an image generation IC, and a sound generation IC and can generate a game image and a game sound stand-alone, the host device 1300 receives a game image and a game A game program or the like for generating sound is delivered to the terminals 1304-1 to 1304-n. On the other hand, if it cannot be generated stand-alone, the host device 1300 generates a game image and a game sound, which is transmitted to the terminals 1304-1 to 1304-n and output at the terminal.
[0060]
The present invention is not limited to that described in the above embodiment, and various modifications can be made.
[0061]
For example, the texture mapping method is not limited to that described in the present embodiment. For example, the texture space is not limited to two dimensions, and may be three dimensions. That is, texture mapping may be performed using a spatial texture.
[0062]
Further, the image expressed by the present invention is not limited to that described in the present embodiment. For example, according to the present invention, a fire spreads in the grass, mowing, an object corroding or burning, a dirt or stain spreading, a building breaking, a cloud in a puddle Various things can be expressed, such as being crowded.
[0063]
Also, the types of material properties are not limited to those described in this embodiment.
[0064]
The present invention is not limited to home and business game devices, but also various image generation devices such as a simulator, a large attraction device in which a large number of players participate, a personal computer, a multimedia terminal, and a system board for generating game images. It can also be applied to.
[0065]
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an image that can be seen when a semi-transparent object is superimposed on a background object.
FIG. 2 is a diagram for explaining the principle of the present embodiment.
FIG. 3 is a diagram illustrating an example of an image that can be seen when an object having a refractive index different from that of the background object is superimposed on the background object.
FIG. 4 is a diagram for explaining the principle of the present embodiment.
FIGS. 5A and 5B are diagrams for explaining a technique for changing the position of the second object in real time; FIGS.
FIGS. 6A and 6B are diagrams for explaining a technique for changing the shape of a second object in real time. FIGS.
FIG. 7 is an example of a functional block diagram of the image generation apparatus of the present embodiment.
FIGS. 8A and 8B are diagrams illustrating examples of images generated according to the present embodiment.
FIG. 9 is a diagram illustrating examples of first and second textures.
FIGS. 10A and 10B are diagrams illustrating examples of images generated according to the present embodiment.
FIG. 11 is a flowchart for explaining a detailed processing example of the present embodiment;
FIG. 12 is a diagram for describing a method for calculating texture coordinates of a second object.
FIG. 13 is a diagram illustrating an example of a hardware configuration capable of realizing the present embodiment.
14A, 14B, and 14C are diagrams illustrating examples of various types of apparatuses to which the present embodiment is applied.
[Explanation of symbols]
20 first texture 22 second texture 30 first object 32 second object 100 processing unit 110 object space setting unit 120 mapping unit 122 texture coordinate calculation unit 130 texture storage unit 150 image generation unit 160 display unit 190 information storage Medium

Claims (4)

An image generation device that generates an image in which material properties of an original image are partially changed ,
A first texture that is created in advance, formed in advance as the first texture original image, a texture memory for storing a second texture totally alter the material properties of the first texture Means,
Object space setting means for arranging the second object so as to overlap the first object;
With mapping the first texture to the first object, and mapping means for mapping the second texture to the second object,
An image that generates an image obtained by superimposing an image obtained by mapping the first texture on the first object and an image obtained by mapping the second texture on the second object without performing translucent processing. Generating means,
The mapping means is
Generating a texture coordinate of the second texture to be given to the vertex of the second object based on a positional relationship between the vertex of the first object and the vertex of the second object apparatus. In claim 1,
The material property is at least one of color, brightness, translucency, reflectance and refractive index;
The texture storage means
An image generating apparatus that stores the second texture in which the color, brightness, translucency, reflectance, or refractive index of the first texture is changed as a whole . In any one of Claims 1 thru | or 2 .
An image generating apparatus comprising: means for changing in real time at least one of a position and a shape of the second object. A computer-readable information storage medium for generating an image in which material properties of an original image are partially changed ,
A first texture that is created in advance, formed in advance as the first texture original image, a texture memory for storing a second texture totally alter the material properties of the first texture Means,
Object space setting means for arranging the second object so as to overlap the first object;
With mapping the first texture to the first object, and mapping means for mapping the second texture to the second object,
An image that generates an image obtained by superimposing an image obtained by mapping the first texture on the first object and an image obtained by mapping the second texture on the second object without performing translucent processing. Let the computer function as a generation means,
In the mapping means,
An information storage medium storing a program for calculating texture coordinates of the second texture to be given to the vertex of the second object based on a positional relationship between the vertex of the first object and the vertex of the second object .

Images