JP4078926B2 - Image generation method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image generation method and apparatus for generating an image when a stereoscopic model is viewed from the viewpoint by setting a stereoscopic model, a light source, and a viewpoint in a stereoscopic space, and in particular, a bump mapping technique using a normal map. The present invention relates to a method and an apparatus for generating an image having a partially different texture by applying the method.
[0002]
[Prior art]
For example, a virtual reality (VR) system includes various three-dimensional models in a three-dimensional coordinate system three-dimensional space virtually represented by three coordinate axes (X axis, Y axis, Z axis) orthogonal to each other in a computer. Set a light source, set a viewpoint that can freely move in the three-dimensional space according to an input signal from the input device, generate an image of the three-dimensional space viewed from this viewpoint, and display it on a screen such as a screen or a display By this, the viewer can get a feeling as if he / she entered the virtual space and was looking at the 3D model.
[0003]
By the way, the surface of the three-dimensional model has various patterns. These patterns are stored in advance in a storage device in the computer as image data called texture. At the time of image generation, the texture image is pasted on the surface of the corresponding three-dimensional model, shaded (shaded) according to the viewpoint, the position of the light source, etc., and displayed on the screen.
[0004]
Further, there is a case where a more realistic image can be obtained by giving an uneven feeling to the pattern. It is possible by shading to make a texture image without unevenness appear as if there is unevenness. Such shading is called bump mapping. As bump mapping, a technique using a normal map is generally used.
[0005]
FIG. 13 shows an example of the normal map 1. The normal map 1 is created corresponding to the image of the texture 2 shown in FIG. As shown in FIG. 15, the normal map 1 indicates the orientation of the pixel p with respect to the three-dimensional coordinate system composed of the X axis, the Y axis, and the Z axis for each normal vector S (X, Y, Z). The vector values of X, Y, and Z are converted into R (Red), G (Green), and B (Blue) values and set for each pixel p. ing. Here, the lengths of the normal vectors S are all normalized to “1”. Accordingly, the magnitude of the gradient of the normal vector S is in the range of −1.0 to 1.0, but the intensity of the color is 0 to 255, and thus, for example, the normal vector S (X, Y, Z) is ( The flat portion of (0.0, 0.0, 1.0) becomes (R, G, B) = (127, 127, 255) and is expressed in blue.
[0006]
FIG. 16 is a flowchart showing the procedure of a conventional bump map process executed by an image generation apparatus that generates this type of image. That is, the image generation apparatus acquires the texture 2 of the image pasted on the surface of the three-dimensional model and the normal map 1 created corresponding to the image of the texture 2 from the storage unit (ST1, ST2).
[0007]
Next, the image generation apparatus calculates, for each pixel p, a light vector indicating the direction of the surface in the light source direction from the direction of the surface of the three-dimensional model to which the texture 2 image is pasted and the position of the light source ( ST3). Next, the image generation apparatus calculates the inner product of this light vector and the normal vector S of the normal map 1 corresponding to the image of the texture 2 for each pixel p, and diffuses (Diffuse). The luminance value of each pixel p with respect to light is obtained (ST4). Thereafter, the luminance value of each pixel p, which is the inner product calculation result (inner product value), is multiplied by the image of the texture 2 to generate a rendered image by diffuse light (ST5).
[0008]
Further, the image generation device calculates the sum of the light direction from the light source of the surface and the line-of-sight direction from the viewpoint from the orientation of the surface of the stereo model to which the image of the texture 2 is pasted and the positions of the light source and the viewpoint. A half-angle vector indicating the direction is calculated for each pixel p (ST6). Next, the image generation apparatus calculates the inner product of the half-angle vector and the normal vector S of the normal map 1 for each pixel p, and the luminance value of each pixel p with respect to specular (specular) light. Is obtained (ST7). Thereafter, the luminance value of each pixel p, which is the result of the inner product calculation, is multiplied by a predetermined specular color to generate a rendered image by specular light (ST8). The specular color is determined by the type of light source that irradiates the surface to which the image of the texture 2 is attached.
[0009]
In this way, when the rendering image by the diffuse light and the rendering image by the specular light are generated, the image generation apparatus adds the both rendering images to obtain a final output image (ST9). Then, the image generation device outputs the final output image to the display device (ST10) and displays it on the screen or display screen.
[0010]
It should be noted that either the rendering image generation process using the diffused light of ST3 to ST5 or the rendering image generation process using the specular light of ST6 to ST8 may be processed first, or may be processed in parallel. Is.
[0011]
FIG. 17 shows an example of an image shaded by the conventional bump map process. This image is obtained by pasting the texture 2 image shown in FIG. 14 on the surface of the three-dimensional model showing the wrinkle at the center of the screen, and the texture 2 image has a gold leaf pasted on portions other than the pine. Therefore, bump map processing is applied to increase the gloss of the gold leaf. However, in the conventional bump map processing, since the glossiness is uniform throughout the whole picture, the whole picture is expressed as being glossy, and the gold leaf portion is not conspicuous.
[0012]
Therefore, as shown in FIG. 18, a texture 3 of a mask image is prepared by blackening a pine portion that does not have a glossy look. Then, as shown by the broken line in FIG. 16, the image generation device multiplies the rendering image by specular light by the mask image to lower the luminance value of the mask portion (ST11), and then displays the rendering image by diffuse light. Addition is performed (ST9) to obtain a final output image (ST10). By doing so, the luster of the pine part to which the gold foil is not attached is suppressed, so that the glossiness of the gold foil is enhanced.
[0013]
Incidentally, in the case of generating the image shown in FIG. 17, a rendering image by the specular light before applying the texture 3 of the mask image is shown in FIG. 19, and by the specular light after applying the texture 3 of the mask image The rendered image is shown in FIG.
[0014]
[Problems to be solved by the invention]
However, when the texture 3 of the mask image is applied because the glossiness of the texture image is partially different, the complexity of having to create the texture 3 of the mask image from the image of the texture 2 in advance. In addition to the texture 2 and the normal map 1, there is also a problem that a storage area for storing and holding the mask image texture 3 is also required, resulting in a large storage capacity. In addition, since a processing step for multiplying the image for masking by the specular light rendered image is added, the processing takes time, and for images that must be generated one after another in a very short time like a virtual reality system. Was unsuitable.
[0015]
The present invention has been made based on such circumstances, and an object of the present invention is to provide an image generation method capable of generating high-quality images with partially different textures with a small number of processing steps and saving storage capacity. The device is intended to be provided.
[0016]
[Means for Solving the Problems]
The present invention solves such a problem, and the invention corresponding to claim 1 sets a solid model, a light source, and a viewpoint in which a texture of an image having a partially different texture is pasted in a three-dimensional space, An image generation method for generating an image when a stereoscopic model is viewed from a viewpoint, wherein the diffused light is obtained by multiplying the texture image by a light vector indicating a direction in a light source direction of a surface on which the texture image of the stereoscopic model is pasted. A normal map corresponding to the texture image and a half-angle vector indicating the sum direction of the light direction from the light source of the surface to which the texture image of the three-dimensional model is pasted and the line-of-sight direction from the viewpoint The inner product with the normal vector is calculated and the specified specular color is multiplied by the inner product value to render the specular light. And generating an output image by adding the rendered image by the diffuse light and the rendered image by the specular light, and the length of the normal vector of the normal map is set to the value of the corresponding texture image. It is different depending on the texture.
[0017]
In the image generation method according to the first aspect of the present invention, the length of each normal vector set for each pixel of the normal map differs depending on the texture difference of the corresponding texture image. Therefore, the rendered image by specular light is generated by calculating the inner product of the half angle vector and the normal vector of the normal map, and multiplying the inner product value by a predetermined specular color. The brightness value of the specular light differs depending on the difference, and the difference in texture is expressed with high quality. If the lengths of the normal vectors are not uniform, the image information of the texture is lost and darkened when calculating the diffuse light. Therefore, in the present invention, a rendering image based on diffuse light is generated by simply multiplying the texture image data by the component in the height direction of the light vector so that the normal vector is not considered in the calculation of diffuse light. .
[0018]
The invention corresponding to claim 2 of the present invention is the invention corresponding to claim 1 described above, wherein the normal map corresponding to the texture of the image partially different in glossiness is the normal vector set for each pixel. Among them, the normal vector of the pixel corresponding to the image that suppresses the glossiness in the corresponding texture image is made shorter than the normal vector of the other pixels.
[0019]
In the image generation method according to the second aspect of the present invention, the normal vector of the normal map is a method in which the normal vector of the pixel corresponding to the image that suppresses the glossiness in the corresponding texture image is a method of another pixel. It is shorter than the line vector. Therefore, in the rendered image by specular light, the luminance of the specular light is reduced in the portion where the normal vector is short, so that the glossiness of the image corresponding to this portion can be suppressed.
[0020]
The invention corresponding to claim 3 of the present invention is an image generation device that sets a stereoscopic model, a light source, and a viewpoint in a stereoscopic space, and generates an image when the stereoscopic model is viewed from the viewpoint, and is pasted on the stereoscopic model. Storage means for storing a texture image and a normal map corresponding to the texture image, and when the texture image is a speckled gloss image, the direction of the surface to which the texture image of the three-dimensional model is pasted in the light source direction A diffuse light rendering means for multiplying the texture image by the light vector shown to generate a rendered image by diffuse light, and the texture image of the three-dimensional model is pasted when the texture image is a speckled image A half-angle vector indicating the direction of the sum of the light direction from the light source and the line-of-sight direction from the viewpoint Specular light rendering means for calculating an inner product with a normal vector of a normal map corresponding to the texture image, multiplying the inner product value by a predetermined specular color and generating a rendered image by specular light, and a diffuse light rendering means Output image generating means for adding the rendered image generated by the diffused light generated by the specular light and the rendered image generated by the specular light generated by the specular light rendering means to generate an output image, and the normal map is a normal vector Are made different depending on the texture of the corresponding texture image.
[0021]
In the image generation apparatus according to the third aspect of the present invention, the storage unit stores the texture image to be pasted on the three-dimensional model and the normal map corresponding to the texture image by the storage unit. Here, in the normal map, the length of the normal vector differs depending on the difference in the texture of the corresponding texture image.
[0022]
The rendered image by the diffuse light is generated by multiplying the texture image by the height direction component of the light vector. On the other hand, the rendered image by specular light is generated by calculating the inner product of the half angle vector and the normal vector of the normal map corresponding to the texture image, and multiplying the inner product value by the specular color. Thus, the rendered image by the diffuse light and the rendered image by the specular light are added to generate an output image having a partially different texture depending on the length of the normal vector.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In this embodiment, a case where a three-dimensional space image displayed in the virtual reality system is generated will be described.
[0024]
FIG. 1 is a block diagram showing the main configuration of an image generation apparatus 10 according to the present embodiment. The image generation apparatus 10 is configured by a computer such as a personal computer or a workstation.
[0025]
The image generation device 10 converts various signals input from the input device 20 into input commands having corresponding contents, and inputs the input commands to the image generation calculation unit 13 and a model file 121. , The light source file 122, the texture file 123, the normal map file 124, etc., the data storage unit 12 as storage means for storing and saving, and the data storage according to the input command given from the input signal conversion unit 11 An image generation calculation unit 13 that generates a stereoscopic space image using the data of the unit 12, a frame memory 14 that stores data of the stereoscopic space image generated by the image generation calculation unit 13, and a storage in the frame memory 14 D / A (decode) that reads the image data, converts it into an analog video signal, and outputs it to the display device 30. And a digital / analog) converter unit 15.
[0026]
The input device 20 is for moving the viewpoint position and line-of-sight direction set in the three-dimensional space. The display device 30 projects and displays a three-dimensional space image on a screen such as a screen or a display.
[0027]
The model file 121 stores and saves data relating to the shape and position of various stereo models set in the stereo space. FIG. 2 shows an example of the data record 41 stored and saved in the model file 121. In FIG. 2, an item “model ID” is a unique code set for each model in order to uniquely identify various stereo models. For example, the file name for each model uniquely determined may be used. The item “shape data” is data indicating each vertex coordinate and the like of the three-dimensional shape of the three-dimensional model in which the corresponding model ID is set. In the item “position coordinates”, a three-dimensional model having a corresponding model ID is installed in a three-dimensional space of a three-dimensional coordinate system virtually represented by three coordinate axes (X axis, Y axis, Z axis) orthogonal to each other. This is data indicating position coordinates. The item “texture No” is an identification symbol that identifies a texture image to be pasted on the surface of the three-dimensional model in which the corresponding model ID is set. This identification symbol may be, for example, a texture image file name.
[0028]
The light source file 122 stores and saves data related to various light sources set in the three-dimensional space. FIG. 3 shows an example of the data record 42 stored and saved in the light source file 122. In FIG. 3, the item “light source ID” is a unique code uniquely set for each light source in order to identify various light sources. The item “type” is data indicating the type of light source (infinite light source, point light source, line light source, ambient light, etc.) for which the corresponding light source ID is set. The item “position coordinates” is data indicating the position coordinates where the light source of the corresponding light source ID is installed in the three-dimensional space of the three-dimensional coordinate system.
[0029]
The texture file 123 stores and saves texture data indicating patterns and materials to be pasted on the surfaces of various three-dimensional models. FIG. 4 shows an example of a data record stored and saved in the texture file 123. In FIG. 4, an item “texture No” is a unique identification symbol set for each texture in order to identify each texture data. For example, the texture number may be a file name of texture data. The item “image data” is image data of a texture for which a corresponding texture No. is set. The item “normal map No.” is an identification symbol that identifies a normal map created from the texture image of the corresponding texture No. For example, the normal map number may be a file name of normal map data. The item “gloss flag” is data for identifying whether or not the texture image of the corresponding texture No. is an image with speckled gloss.
[0030]
Further, the file of the texture file 123 may be provided with an item called “rendering instruction”. This rendering instruction describes an instruction for rendering the surface of the model. For example, the rendering instruction is normal bump mapping for model A, normal map A and normal map B for model B, normal map B for model C, and model D for model D. As in the normal map E required for carrying out the present invention, the three-dimensional model and the method are associated with each other. By describing such a rendering instruction in a file, it is possible to associate a method such as the same normal map with different three-dimensional models. This eliminates the need to record duplicate normal maps.
[0031]
The normal map file 124 stores and saves data related to normal maps generated from various texture images. FIG. 5 shows an example of a data record stored and saved in the normal map file 124. In FIG. 5, an item “normal map No” is a unique identification symbol set for each normal map in order to identify each normal map. Each “normal map data” is a normal vector of each pixel of the normal map in which the corresponding normal map No is set.
[0032]
Further, the records of the various files shown in FIGS. 2 to 5 may be integrated into one file and one record. In this case, duplicate items are omitted.
[0033]
Here, in the present embodiment, the restriction of normalizing the length of each normal vector performed by the conventional method to 1 is removed, and each normal vector set for each pixel of the normal map is removed. The size is varied depending on the difference in texture of the corresponding texture image. Such a normal vector is calculated by the following equation (1), for example.
[0034]
(R, G, B) = [(r, g, b) − (127, 127, 127)] × α + (127, 127, 127) (1)
Here, r, g, and b are RGB values corresponding to the X, Y, and Z vectors when the normal vector is normalized to 1, respectively. α is optional within the range of 0 ≦ α ≦ 1.
[0035]
In the image generation apparatus having such a configuration, the image generation calculation unit 13 sets the various three-dimensional models set in the model file 121 and the various light sources set in the light source file 122 in the three-dimensional space of the three-dimensional coordinate system. When the viewpoint position and the line-of-sight direction are determined by the input signal from the input device 20, an image of the three-dimensional space viewed from the viewpoint is generated. At this time, the image generation calculation unit 13 performs bump map processing on a predetermined three-dimensional model, and pastes a texture image with a sense of unevenness on the surface of the three-dimensional model.
[0036]
FIG. 6 is a flowchart showing a procedure of bump map processing executed by the image generation calculation unit 13. First, when the image generation calculation unit 13 acquires the texture No. of the texture image data to be pasted on the model from the data record 41 related to the three-dimensional model acquired from the model file 21, the data record of the texture No. from the texture file 123 as ST21. 43 is read.
[0037]
Next, in ST22, the image generation calculation unit 13 detects the normal map No. from the texture data record 43, and reads the data record 44 of the normal map No. from the normal map file 124.
[0038]
Next, the image generation calculation unit 13 checks the gloss flag of the texture data record. When the gloss flag indicates that the image has a glossy appearance, a rendering image generation process using diffuse light shown in ST24 and ST25 and a rendering image generation process using specular light shown in ST26 to ST28 are executed. Note that either of these processes may be processed first, or both may be processed in parallel.
[0039]
That is, the image generation calculation unit 13 calculates, for each pixel p, the light vector indicating the direction of the surface in the light source direction from the direction of the surface of the stereo model to which the texture image is pasted and the position of the light source in ST24. . Then, in ST25, the image generation calculation unit 13 reads the image data (texture image data) of the texture data record 43 obtained by reading the height direction component of the light vector (usually the Z-axis component of the light vector) from the texture file 123. ) To generate a rendering image by diffuse light (diffuse light rendering means).
[0040]
In ST26, the image generation calculation unit 13 determines the direction of the light from the light source on the surface and the direction of the line of sight from the viewpoint based on the orientation of the surface of the stereo model to which the texture image data is pasted and the positions of the light source and the viewpoint. A half-angle vector indicating the direction of the sum of is calculated for each pixel. Next, the image generation calculation unit 13 calculates, for each pixel, an inner product of this half angle vector and the normal map data (normal vector S) of the normal map data record 44 read from the normal map file 124. Thus, an inner product value, that is, a luminance value of each pixel with respect to specular light is obtained. Then, the luminance value of each pixel, which is the result of the inner product calculation, is multiplied by a predetermined specular color to generate a rendering image using specular light. Note that the specular color is determined by the type of light source that irradiates the surface to which the texture image is attached.
[0041]
In this way, if the rendering image by the diffuse light and the rendering image by the specular light are generated, the image generation calculation unit 13 adds both the rendering images to obtain a final output image in ST29. Therefore, the image generation calculation unit 13 draws and outputs the final output image to the frame memory 14 in ST30.
[0042]
The image data of the final output image drawn in the frame memory 14 is converted into an analog video signal by the D / A conversion unit 15 and displayed on a screen such as a screen or a display by the display device 32. .
[0043]
In the present embodiment configured as described above, for example, when generating the three-dimensional space image shown in FIG. 12, the texture of the lacquer that is pasted on the surface of the three-dimensional model that forms the wrinkle at the center of the screen in advance is shown in FIG. The texture 2 of the image shown in FIG. 7 is stored in the texture file 123, and as a normal map corresponding to the image of the texture 2, as shown in FIG. A normal map 1 ′ in which the normal vector is shorter than the normal vector of the pixel corresponding to the glossy gold foil portion is stored in the normal map file 124.
[0044]
Then, when the image generation calculation unit 13 executes bump map processing on the three-dimensional model, a light vector as shown in FIG. 8 is calculated, and a component in the height direction of the light vector is converted into the image data of the texture 2. Multiplication is performed to generate a rendered image with diffuse light as shown in FIG. Further, a half angle vector as shown in FIG. 9 is calculated, and an inner product of the half angle vector and the normal vector of the normal map 1 ′ is calculated, and then the inner product value, that is, the luminance value is set to a predetermined specular color. Is multiplied to generate a rendering image by specular light as shown in FIG. Then, the rendered image by the diffused light and the rendered image by the specular light are added to obtain a final output image as shown in FIG. Since this final output image suppresses the gloss of the portion of the normal map 1 'where the normal vector is short, that is, the non-glossy pine portion, on the contrary, the portion where the normal vector is long, that is, the gold foil is pasted. The glossiness of the existing portion is enhanced, and an image having a quality equivalent to or close to that when the texture 3 of the conventional mask image is used is obtained.
[0045]
Therefore, according to the present embodiment, the texture 3 of the mask image can be made unnecessary, so that the trouble of creating the texture 3 of the mask image can be eliminated and the memory for storing the texture of the mask image can be saved. The storage capacity of the part can be saved. In addition, the processing step of multiplying the rendered image by specular light by the texture 3 of the mask image becomes unnecessary, and the number of processing steps is reduced, so that the processing time can be shortened.
[0046]
In addition, if the lengths of the normal vectors are not uniform, the texture image information may be lost when the diffuse light is calculated, and blackening may occur. However, in this embodiment, the normal vector is used for calculating the diffuse light. Therefore, such a problem cannot occur because the rendering image by the diffused light is generated only by multiplying the texture image data by the height vector component of the light vector.
[0047]
Note that the present invention is not limited to the image generation technique in the virtual reality system, and can be applied, for example, when generating a three-dimensional space image in a CG animation or a TV game.
[0048]
The present invention is also effective when applied to the generation of images having different textures other than the gold foil portion.
[0049]
In the prior art, the brightness value of the diffuse light is obtained by calculating the inner product of the light vector and the normal vector. In the present invention, the normal vector is vertically upward (0, 0) in all pixels. , 1), the luminance value is obtained only with the height component of the light vector. Therefore, in the present invention, if the three-dimensional space image is a flat surface that receives light completely uniformly, a further texture and gloss can be produced.
[0050]
【The invention's effect】
As described above in detail, according to the invention corresponding to claim 1, it is possible to provide an image generation method capable of generating images with partially different textures with high processing quality with a small number of processing steps and saving storage capacity.
[0051]
Further, according to the invention corresponding to claim 2, it is possible to provide an image generation method capable of generating images with partially different glossiness with high processing quality with few processing steps and saving storage capacity.
[0052]
According to the invention corresponding to claim 3, it is possible to provide an image generating apparatus that can generate images with partially different textures with high processing quality with a small number of processing steps and save storage capacity.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main configuration of an image generation apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing an example of a data record stored in a model file of the image generation apparatus according to the embodiment.
FIG. 3 is a schematic diagram showing an example of a data record stored in a light source file of the image generation apparatus according to the embodiment.
FIG. 4 is a schematic diagram illustrating an example of a data record stored in a texture file of the image generation apparatus according to the embodiment.
FIG. 5 is a schematic diagram showing an example of a data record stored in a normal map file of the image generation apparatus according to the embodiment.
FIG. 6 is a flowchart showing a main procedure of bump map processing executed by an image generation calculation unit of the image generation apparatus according to the embodiment;
FIG. 7 is an image showing a normal map used in the embodiment.
FIG. 8 is a conceptual diagram of a light vector calculated in the embodiment.
FIG. 9 is a conceptual diagram of a half angle vector calculated in the embodiment.
FIG. 10 is a rendering image by diffuse light generated in the embodiment.
FIG. 11 is a rendering image by specular light generated in the embodiment.
FIG. 12 shows a final output image generated in the embodiment.
FIG. 13 is an image showing a normal map used in the conventional description.
FIG. 14 is an image showing a texture used in the embodiment and the conventional description.
FIG. 15 is a conceptual diagram used for explaining a normal map.
FIG. 16 is a flowchart showing a main procedure of bump map processing performed at the time of conventional image generation;
FIG. 17 is an output image generated by conventional bump map processing.
FIG. 18 is a mask image used in the prior art.
FIG. 19 is a rendering image by specular light generated by conventional bump map processing.
FIG. 20 is a rendering image by specular light generated by bump map processing using a conventional mask image.
[Explanation of symbols]
1,1 '... Normal map
2 ... Texture
10. Image generating device
11 ... Input signal converter
12. Data storage unit
13. Image generation calculation unit
14: Frame memory
15 ... D / A converter
20 ... Input device
30 ... Display device
121 ... Model file
122: Light source file
123 ... Texture file
124 ... Normal map file

Claims (3)

An image generation method for setting a solid model, a light source, and a viewpoint each having a texture of an image having a partially different texture in a three-dimensional space, and generating an image when the stereoscopic model is viewed from the viewpoint ,
Multiplying the texture image by a light vector indicating the direction of the surface of the stereo model to which the texture image is pasted in the light source direction to generate a rendered image by diffuse light;
A half-angle vector indicating the direction of the sum of the light direction from the light source and the line-of-sight direction from the viewpoint of the surface to which the texture image of the stereo model is pasted, and the normal vector of the normal map corresponding to the texture image And calculating a dot product with the specular light by multiplying the dot product value by a predetermined specular color;
Adding the rendered image by the diffused light and the rendered image by the specular light to generate an output image,
An image generation method characterized in that the length of a normal vector of the normal map is made different depending on the texture of the corresponding texture image. The image generation method according to claim 1,
The normal map corresponding to the texture of an image with partially different glossiness is the normal line of the pixel corresponding to the image whose glossiness is suppressed in the corresponding texture image among the normal vectors set for each pixel. An image generation method, wherein a vector is shorter than a normal vector of another pixel. In an image generation device that sets a stereoscopic model, a light source, and a viewpoint in a stereoscopic space, and generates an image when the stereoscopic model is viewed from the viewpoint,
Storage means for storing a texture image to be pasted on the three-dimensional model and a normal map corresponding to the texture image;
When the texture image is a speckled image of gloss, the texture image is multiplied by a light vector indicating the direction of the surface to which the texture image of the three-dimensional model is pasted in the light source direction, and diffused light is used. A diffuse light rendering means for generating a rendered image;
When the texture image is a speckled image, a half indicating the sum direction of the light direction from the light source and the line-of-sight direction from the viewpoint of the surface to which the texture image of the three-dimensional model is attached A specular light rendering unit that calculates an inner product of an angle vector and a normal vector of a normal map corresponding to the texture image, and multiplies the inner product value by a predetermined specular color to generate a rendered image by specular light;
An output image generation means for generating an output image by adding a rendering image by diffuse light generated by the diffuse light rendering means and a rendering image by specular light generated by the specular light rendering means;
The image generating apparatus according to claim 1, wherein the normal map is obtained by changing the length of a normal vector depending on a difference in texture of a corresponding texture image.

Images