JP2000348196A - Three-dimensional image generation device and environment map generation method - Google Patents

Abstract

(57) Abstract: The present invention relates to a three-dimensional image generation device, and an object of the present invention is to efficiently store an environment map necessary for executing an environment mapping using a mip mapping method in a cube memory. I do. A cube memory (18) capable of specifying a memory address by designating two-dimensional coordinates is provided. An environment map having a mipmap structure including environment maps 20, 20-1, 20-2, and 20-3 having a reduced scale of 1/2 as a common ratio is stored in the cube memory 18. Environment map 20, 2
Each of 0-1, 20-2, and 20-3 has six pieces of image data projected on each surface of the cube. The six image data are arranged in an L-shape occupying 3/4 of the memory area having an aspect ratio of 1: 2. The small scale environment maps are sequentially arranged in a memory area having an aspect ratio of 1: 2 circumscribing the concave corners of the L-shaped memory area occupied by the large scale environment map.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a three-dimensional image generating apparatus and an environment map generating method, and more particularly to a mip.
The present invention relates to a three-dimensional image generation apparatus that executes environment mapping using a technique of (MIP: Multum in Parvo) mapping, and a method of generating an environment map suitable as a method of generating an environment map used for the processing.

[0002]

2. Description of the Related Art Conventionally, as one of the methods for enhancing the realism of a three-dimensional image, environment mapping for reflecting the surrounding environment on the surface of an object is known. A method of generating a three-dimensional image using environment mapping is described in, for example, “Reflecti
on Vector Shading Hardware "(Douglas Voorhies and J
im Foran: SIGGRAPH 94 Conference Proceedings, P16
It is disclosed in 3).

According to this technique, environment mapping is performed using an environment map having a memory area corresponding to each surface of a predetermined cube. Hereinafter, the memory area corresponding to each of these surfaces is referred to as “each surface of the environment map” for convenience. Each plane of the environment map stores image data obtained by projecting a landscape (including a distant view at infinity) in a three-dimensional space surrounding the above-described cube toward each center toward the center of the cube. Have been.

[0004] An object to be subjected to environment mapping (hereinafter referred to as an "object to be displayed") is virtually located at the center of a cube corresponding to the environment map. The displayed object is
The image is displayed as a two-dimensional image on a display unit having a plurality of pixels arranged two-dimensionally. The environment mapping process is performed on a pixel-by-pixel basis. Hereinafter, one pixel being processed is referred to as a “pixel of interest”, and a pixel is referred to as a “dot”.
Consider

In the environment mapping process, a line of sight from the pixel of interest to the object to be displayed is set for each pixel of interest under the above-described virtual situation, and a point where the line of sight intersects the object to be displayed is reflected. Defined as a point. A normal vector is determined in advance for each point of the displayed object, and when a reflection point is set as described above, a reflection vector of a line of sight at the reflection point is obtained based on the normal vector of the point. .

[0006] The line-of-sight reflection vector is a vector in the opposite direction to the light that generates reflected light from the reflection point toward the target vector. Therefore, if the color of the scenery present in the direction of travel of the reflection vector is reflected on the color of the pixel of interest, it is possible to realize an expression as if the scenery is reflected at the reflection point. In the environment mapping processing, the intersection between the reflection vector and the environment map determined as described above is determined as a reference point, and the image data of the reference point (the luminance of each color component, etc.)
Is reflected in the color of the pixel of interest. As a result, an object to be displayed that reflects the surrounding environment is displayed on the display unit.

[0007] The scale of the scene projected on the display object by the environment mapping changes according to the curvature of the surface of the object. By the way, if the size of the landscape stored in the environment map, that is, the size of the picture (hereinafter, referred to as “original picture”) that is the source of the landscape projected on the display target object is constant, When displaying a large image, many points on the original picture are sampled, and when displaying a small landscape, a small number of points on the original picture may be sampled.

When the display is to be reproduced based on the sampling result of the original picture, if the original picture contains a frequency component exceeding 1/2 of the sampling frequency, aliasing, that is, a reproduction screen A failure that causes a problem such as a flicker occurs on the top. Therefore, if the original picture is too large for the scene to be displayed by the environment mapping, that is, if the resolution of the original picture is too high, the sampling density becomes inappropriately small and aliasing may occur.

Conventionally, mip mapping has been known as a method for preventing the above-mentioned aliasing. In the mip mapping, a plurality of original pictures of different sizes prepared in advance for the same image are used. More specifically, in mip mapping, a predetermined number of original pictures (usually 2 pictures) are selected from a plurality of original pictures according to the size of the image to be displayed.
Is selected, and image data of each pixel is obtained by interpolating image data sampled from each of the predetermined number of original pictures.

According to the mip mapping described above, it is possible to prevent the sampling density for the original picture from becoming too small. For this reason, by performing the conventional environment mapping in combination with the above-described mip mapping, it is possible to effectively prevent the occurrence of aliasing regardless of the size of the scenery projected on the display target object. .

[0011]

In order to execute the conventional environment mapping, images of six planes corresponding to each plane of the cube are required. Therefore, in order to perform the environment mapping and the mip mapping in combination, a plurality of original pictures having different sizes are required for each of the six images.

In order to eliminate waste occurring in the memory area,
It is desirable that the plurality of original pictures be efficiently stored in the memory. Also, in order to facilitate the design of the environment map, the data of six images drawn at the same scale,
It is desirable that the connection between images be stored two-dimensionally in an arrangement that is easy to understand sensory. Furthermore, in order to facilitate the execution of the mip mapping, it is necessary to easily correspond the same point on a plurality of images having different scales without performing complicated coordinate transformation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and stores an environment map required to execute both environment mapping and mip mapping in a state satisfying the above-mentioned requirements. A first object is to provide a three-dimensional image generation device.

It is a second object of the present invention to provide a method of generating an environment map capable of generating an environment map stored in a state satisfying the above requirements.

[0015]

According to a first aspect of the present invention, there is provided a three-dimensional image generating apparatus for performing environment mapping in which a surrounding scene is projected on a surface of an object to be displayed. There is provided a memory which can be used as a two-dimensional memory capable of specifying a memory address by designating two-dimensional coordinates. The memory includes a plurality of environment maps having a reduced scale forming a geometric progression having a common ratio of 1/2. An environment map having a mipmap structure is stored. Each of the plurality of environment maps has image data corresponding to six images projected on each surface of the cube, and each of the plurality of environment maps has The image data of the six images is stored in the memory in an L-shape occupying 3/4 of the memory area having an aspect ratio of 1: 2, and the environment map of the mipmap structure is scaled. of The environment maps are sequentially stored in a memory area having an aspect ratio of 1: 2 circumscribing the concave corners of the L-shaped memory area occupied by the large-scale environment map. It has a configuration to be performed.

According to a second aspect of the present invention, there is provided the three-dimensional image generating apparatus according to the first aspect, wherein the arrangement of the image data for the six images included in each of the plurality of environment maps is performed on all the environment maps. Of the plurality of environment maps, the smaller scale environment map is stored in the memory area closer to the origin (0, 0) of the memory than the memory area occupied by the larger scale environment map. It is configured to:

According to a third aspect of the present invention, in the three-dimensional image generating apparatus according to the first or second aspect, the image data of the six images included in each of the plurality of environment maps includes The image is configured to be stored in the memory in a state where the continuity of the images on five of the six surfaces is maintained.

According to a fourth aspect of the present invention, there is provided the three-dimensional image generating apparatus according to any one of the first to third aspects, wherein:
The image data of the six images included in each of the plurality of environment maps includes, among the images projected on the cube, four images located on the front, back, right, and left in relation to the display target object Is stored in the memory in a state where continuity is maintained.

According to a fifth aspect of the present invention, in order to achieve the second object, in the process of generating a three-dimensional image, it is referred to when performing environment mapping in which the surrounding scenery is projected on the surface of the display target object. Generating an image data corresponding to six images projected on each surface of a cube, based on the six image data; Creating an environment map of a mipmap structure including a plurality of environment maps,
Storing a mipmap structure environment map in a memory having a memory area associated with a cubic surface, wherein a memory address can be specified by specifying dimensional coordinates. Image data of six images included in each of the environment maps is stored in the memory in an L-shape occupying 3/4 of a memory area having an aspect ratio of 1: 2, and the mip map structure is provided. In the environment map, the small-scale environment map is sequentially arranged in the memory area having an aspect ratio of 1: 2 circumscribing the concave corner of the L-shaped memory area occupied by the large-scale environment map. Has a configuration stored in the memory.

According to a sixth aspect of the present invention, there is provided the environment map generating method according to the fifth aspect, wherein the arrangement of the six pieces of image data included in each of the plurality of environment maps includes:
All of the environment maps are unified, and among the plurality of environment maps, the smaller scale environment map is located closer to the origin (0,0) of the memory than the memory area occupied by the larger scale environment map. It is configured to be stored in the area.

According to a seventh aspect of the present invention, there is provided the environment map generating method according to the fifth or sixth aspect, wherein the image data of the six images included in each of the plurality of environment maps includes the image data of the cube. The image is configured to be stored in the memory in a state where the continuity of the images on five of the six surfaces is maintained.

The invention according to claim 8 is the method for generating an environment map according to any one of claims 5 to 7, wherein the image data of six images included in each of the plurality of environment maps is provided. Is stored in the memory in a state where continuity of four images located on the near side, the back side, the right side, and the left side in relation to the object to be displayed among the images projected on the cube is maintained. Is configured.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 shows a block diagram of a three-dimensional image generation device according to Embodiment 1 of the present invention. As shown in FIG. 1, the three-dimensional image generation device of the present embodiment includes a geometry unit 10, a rendering unit 12, a memory unit 14, and a display unit 16.

The geometry section 10 is a section for executing a process of generating data of a three-dimensional image to be displayed, a process of converting the generated data of the three-dimensional image into two-dimensional data, and outputting the data.

The rendering unit 12 is a unit that executes various processes necessary for rendering a three-dimensional image on the display unit 16. The processing in the rendering unit 12 is executed based on data supplied from the geometry unit 10, various data stored in the memory unit 16, and the like.

The memory unit 14 is an area for storing information necessary for executing the processing of the rendering unit 12. In the present embodiment, the memory unit 14 includes a Z buffer (not shown) for storing depth information of polygons constituting the three-dimensional image, and a texture memory (not shown) for storing data relating to texture used for the three-dimensional image. And a cube memory 18 for storing an environment map necessary for processing the environment mapping. In this embodiment, the cube memory 18 corresponds to the “memory” in the first aspect.

The display section 16 is a section for displaying a three-dimensional image by appropriately coloring each of a plurality of pixels arranged two-dimensionally. In the present embodiment, the display unit 16 displays a three-dimensional image by receiving rendering data for each pixel from the rendering unit 12.

In the three-dimensional image apparatus according to the present embodiment, the rendering unit 16 executes environment mapping, that is, a process of reflecting the surrounding environment on the surface of the display object forming the three-dimensional image. FIG. 2 is a conceptual diagram illustrating the contents of environment mapping. The environment mapping is performed using the environment map 20 shown in FIG. The environment map 20 is stored in the cube memory 18 and has a memory area corresponding to each surface of a predetermined cube assumed in a predetermined three-dimensional space. Hereinafter, the memory area corresponding to each of these surfaces is referred to as “each surface of the environment map 20” for convenience.

On each surface of the environment map 20, image data on a landscape (including a distant view at infinity) in the three-dimensional space surrounding the above-mentioned cube is more specifically directed to the center of the cube. Data of an image obtained by projecting on each surface of the cube is stored. In the image data, for example, the luminance of each color component (R, G, B, etc.) at each point on the cube, the opacity indicating the opacity of each point, and the like are stored.

In the environment mapping process, an object (hereinafter, referred to as “displayed object 22”) to be reflected in the surrounding landscape is arranged at the center of the cube corresponding to the environment map 20. For convenience of explanation, FIG. 2 shows the displayed object 22 in a large size. However, in the environment mapping processing, the displayed object 22 is infinitesimal, and all the points on the surface are collected at the center point of the cube. Is treated as if it were.

The object 22 to be displayed is displayed on the display section 16 having a plurality of pixels arranged two-dimensionally. Hereinafter, a pixel corresponding to each point of the display target object 22 is referred to as a “pixel of interest”, and the pixel is regarded as a point. In the environment mapping process, the display object 2
2 is set, and a point at which the line of sight 24 intersects the displayed object 22 is defined as a reflection point 26.

With respect to the displayed object 22, a normal vector (not shown) is determined in advance for each point on the surface. In the environment mapping process, for the reflection point 26 set as described above, the reflection vector 28 of the line of sight 24 is obtained based on the normal vector of the point. The reflection vector 28 is a vector in the opposite direction to the light that generates reflected light from the reflection point 26 toward the target vector. Therefore, by reflecting the color of the scenery existing in the traveling direction of the reflection vector 28 on the color of the pixel of interest, it is possible to realize an expression as if the scenery is reflected at the reflection point 26.

In the environment mapping process, the intersection between the reflection vector 28 and the environment map 20 determined as described above is determined as a reference point 30, and an image to be reflected on each pixel of interest using data on the reference point 30. Data is calculated. As a result, the display object 16 is displayed on the display unit 16, reflecting the surrounding environment.

In the three-dimensional image generating apparatus according to the present embodiment, the rendering unit 12 performs a mip mapping process together with the above-described environment mapping. FIG. 3 is a conceptual diagram for explaining the contents of mip mapping. More specifically, FIG. 3A shows the original picture (plane 0) of scale 1 referred to during mip mapping, and FIG. 3B shows the same image as plane 0 at scale 1/2. Fig. 3 shows the original picture (side 1)
(C) shows the original picture (Surface 2) in which the same image as plane 0 was drawn at a scale of 1/4, and FIG. 3 (D) shows the original picture in which the same image as plane 0 was drawn at a scale of 1/8. (Surface 3) is shown.

The mip mapping is shown in FIGS.
This is performed using a plurality of original pictures as shown in (D), that is, a plurality of original pictures representing the same image at different scales. That is, in the process of mip mapping, a predetermined number (for example, two) of original pictures whose scales are similar to the image to be displayed are selected from the plurality of original pictures described above, and the images sampled from those original pictures are selected. The image data of each pixel is calculated by performing the interpolation process using the data.
The desired number of original pictures having different scales can be provided by changing the scale in a geometric progression. Less than,
These series of original pictures with different scales are called “mip maps”
A structure in which a series of original pictures having different scales are combined is referred to as a “mip map structure”.

In the present embodiment, mip maps are prepared for each of the six landscape images projected on each surface of the cube corresponding to the environment map 20. In other words, in the present embodiment, the cube memory 18 has
A plurality of environment maps having different scales are stored in the mipmap structure described above. Hereinafter, "Environment Map 20"
Is an environment map corresponding to “Surface 0” shown in FIG.
That is, it refers to an environment map of a scale 1/1.
When it is necessary to particularly designate an environment map of a scale 1/2 or less corresponding to "surface 1" and thereafter, the environment map is described as "environment map 20-n" (n is an integer).

The rendering unit 12, as shown in FIG.
Cube address generator 32, environment generator 34,
And a color calculation unit 36. In the cube address generation unit 32, the following processing is executed. (1) The line of sight 24 and the reflection vector 28 are generated for each pixel of interest by the above-described method, and an environment map 2 with a scale of 1/1
The process of determining the reference point 30 on 0. (2) A process of selecting two environment maps 20-n to be referred to according to the size of an image to be displayed. (3) Processing for finding points corresponding to the reference points 30 on the selected environment map 20-n and outputting the addresses on the cube memory 18 corresponding to those points (hereinafter referred to as "cube addresses"). .

The cube address output from the cube address generator 32 is supplied to an environment generator 34. In the environment generator 34, the following processing is executed. (1) A process of accessing the cube memory 18 and reading out image data corresponding to the cube address. (2) A process of obtaining image data suitable for the size of an image to be displayed by performing an appropriate interpolation process using the image data read from the cube memory 18.

The image data obtained by the environment generator 34 is supplied to a color operation unit 36. The color calculation unit 36 calculates data on a color to be developed at the target pixel by reflecting the image data calculated by the environment generator 34 on the image data calculated by the other parts of the rendering unit 12. The data generated by the color calculation unit 36 is supplied to the display unit 16. As a result, the display target object 22 on which the landscape is projected is displayed on the display unit 16.

As described above, the rendering unit 12 uses the mipmap structure environment map stored in the cube memory 18 to combine the mip mapping and the environment mapping to obtain image data to be reflected on the target pixel. According to the mip mapping, it is possible to prevent the sampling density for the original picture from largely changing according to the size of the scene to be displayed, and to prevent aliasing from occurring in a small image. Therefore, according to the three-dimensional image generation device of the present embodiment, the display object 22
It is possible to project a detailed scenery of any size on the surface of the camera.

In the three-dimensional generating apparatus of the present embodiment, the two-dimensional data (x, y) is converted into a memory address of the cube memory 18 inside the cube memory 18, inside its interface, or inside the environment generator 34. A conversion unit is included. Therefore, in the present embodiment, the cube memory 18 can be used as a memory that can specify a memory area by designating two-dimensional coordinates (hereinafter, referred to as “two-dimensional memory”).

The three-dimensional generating apparatus according to the present embodiment is different from the three-dimensional generating apparatus in that an environment map having a mipmap structure is stored in a cube memory 18 which can be treated as a two-dimensional memory as described above in a state described below. Has features.
Hereinafter, the characteristic portion of the present embodiment will be described with reference to FIGS.

FIG. 4A shows an example of a development view of a cube corresponding to the environment map 20. The environment map 20 stores six landscape images as described above. FIG.
In (A), “up”, “down”, “left”, “right”,
“Front” and “back” indicate the directions of the screen to the viewer, respectively. However, the relationship between the front and back is the direction viewed from the display target object. Therefore, in FIG. 4, the left and right are reversed. The data of the six scenery images is obtained by developing each surface onto which the images are projected as shown in FIG. 4A, for example, while maintaining the continuity of the images to the maximum.
It can be stored in a dimensional data area.

Accordingly, the cube memory 18 is stored in FIG.
If a memory area of the same two-dimensional shape as that of the developed view shown in (A) is secured and the image data is stored in the memory area in the same arrangement as the developed view, the mutual continuity of the images on each surface is maintained to the maximum. In this state, the image data of the environment map 20 can be stored in the cube memory 18. However, FIG.
The arrangement of the development view shown in FIG.
8, the useless area is easily generated in the cube memory 18.

For this reason, in this embodiment, FIG.
As shown in (B), the image data of the environment map 20 is stored in the cube memory 18 in a state where the image data of “lower” is moved to a position in contact with both “up” and “left”. By arranging the image data of the environment map 20 in this way, it is possible to efficiently store the data in the cube memory 18 while maintaining the continuity of the five landscape images.

FIG. 5 is a conceptual diagram showing a memory area of the cube memory 14 used in the present embodiment. In the present embodiment, the cube memory 14 is provided with a memory area having an aspect ratio of 1: 2 and an area of 4/3 of the total area of the environment map 20. As shown in FIG. 5, the data of the environment map 20 is stored in the cube memory 14 so that the vicinity of the origin (0, 0) of the cube memory 14 becomes an unused area.

When the environment map 20 is stored in the cube memory 14 as described above, an area not used by the environment map 20 near the origin (0,0) of the cube memory 14 becomes an area used by the environment map 20. Only 1/3 of the remaining. In the present embodiment, the unused area stores the data of the environment map 20-1 arranged in the state shown in FIG. The total area of the environment map 20-1 whose scale is 1/2 is 1 of the total area of the environment map 20 whose scale is 1/1.
Therefore, the environment map 20-1 can be stored in the unused area described above.

Similarly, the environment map 20-2 is sequentially arranged in an area not used by the environment map 20-1, and the environment map 20-3 is sequentially arranged in an area not used by the environment map 20-2. As described above, inside the cube memory 18 used in the present embodiment, the data of the environment map having the mipmap structure is stored in the entire area of the environment map 20 without generating a useless memory area. ３ is efficiently stored in a memory area having an area of.

As described above, the individual environment maps 20, 20-1, 20-2,
.. Are stored in a state where the continuity of five landscape images among the six landscape images is maintained. In particular, in the present embodiment, the front side, the back side,
The continuity of the left and right images is maintained. The scenery surrounding the display target object 22 is easier to understand intuitively as the continuity of the individual scenery images is maintained. In particular, when the continuity of the front, back, left, and right images that should be continued in the horizontal direction is maintained, it is easy to intuitively understand the scenery. A system using environment mapping is easier to handle as the scenery used for environment mapping is more intuitively understood. For this reason, according to the three-dimensional image generation device of the present embodiment, an effect that handling becomes easy can be obtained.

Further, in the three-dimensional image generating apparatus according to the present embodiment, the environment map having the mipmap structure has a reduced scale of 1 /.
The data area is stored in the cube memory 18 such that the data area approaches the origin (0, 0) every time the value becomes 2. According to such a data structure, after determining the reference point 20 on the environment map 20, the x and y coordinate values of the reference point 20 are both reduced to １ ／.
, The coordinate value (x / 2, y / 2) of the corresponding point on the environment map 20-1 can be obtained.

Further, the x and y coordinate values of the reference point 20 are set to 1
と す る or ８, the environment map 20-
2 or the coordinate value (x / 4, y /
2) or (x / 8, y / 8). As described above, according to the data structure of the environment map used in the present embodiment, the coordinate conversion required in the process of the mip mapping can be realized by an easy process. Therefore, according to the three-dimensional image generation device of the present embodiment, mip mapping processing can be easily performed.

[0052]

According to the first aspect of the present invention, six pieces of image data included in each of the plurality of environment maps are stored in the memory in a state of being arranged in a predetermined L-shape. Further, the image data of the environment maps are stored in the memory such that the image data of the small scale environment map sequentially circumscribes the concave corners of the L-shaped memory area occupied by the large scale environment map. Is done. According to such a structure, an environment map having a mipmap structure including a plurality of environment maps having different scales can be efficiently stored in the memory. Therefore, according to the present invention, it is possible to reduce the size and cost of the three-dimensional image generation device.

According to the second aspect of the present invention, the plurality of environment maps included in the mipmap-structured environment map are arranged so that the memory does not occupy the memory area near the origin (0,0). Is stored in the memory area. Also,
In the present invention, the memory area in which each of the environment maps is stored approaches the origin (0, 0) every time the scale of the environment map is reduced to half. In this case, assuming that the coordinates of an arbitrary point on a predetermined environment map are (x, y), the point corresponding to the arbitrary point on the environment map having a scale 1/2 that of the scale of the environment map. The coordinates of the point are (x / 2, y /
2). Therefore, according to the present invention, mutually corresponding points on an environment map having a mipmap structure can be easily associated only by performing simple coordinate conversion. Therefore, according to the present invention, it is possible to realize a process combining the mip mapping and the environment mapping by a simple process.

According to the third aspect of the present invention, each of the plurality of environment maps included in the environment map having the mipmap structure is stored in the memory while maintaining the continuity of the five image data. . According to such an arrangement of the image data, the image stored in the environment map can be easily and intuitively understood. For this reason, according to the present invention, the handling of the three-dimensional image generation device can be facilitated.

According to the fourth aspect of the present invention, each of the plurality of environment maps included in the mipmap structure environment map indicates the continuity of the four image data located at the front, back, right, and left. It is stored in the memory as it is maintained. According to such an arrangement of the image data, it is possible to intuitively and particularly easily understand the image stored in the environment map. For this reason, according to the present invention, the handling of the three-dimensional image generation device can be facilitated.

According to the fifth aspect of the present invention, it is possible to efficiently store, in a memory, six pieces of image data included in each of a plurality of environment maps in a state of being arranged in a predetermined L-shape. it can. For this reason, according to the present invention, an environment map for performing a combination of mip mapping and environment mapping can be manufactured inexpensively with small memory consumption.

According to the present invention, a plurality of environment maps included in the environment map having the mipmap structure can be efficiently stored in the memory in a state where the corresponding points can be associated by simple coordinate conversion. it can. For this reason, according to the present invention, it is possible to easily generate an environment map suitable for realizing a process combining the mip mapping and the environment mapping with a simple process.

According to the seventh aspect of the present invention, each of the plurality of environment maps included in the mipmap structured environment map is stored in the memory such that the continuity of the five image data is maintained. Can be. For this reason, according to the present invention, it is possible to generate an environment map that stores an image in a state in which it is easy to intuitively understand.

According to the eighth aspect of the present invention, each of the plurality of environment maps included in the mipmap structure environment map is used to determine the continuity of the four image data located at the front, back, right, and left. It is stored in memory to be maintained. For this reason, according to the present invention, it is possible to generate an environment map that stores an image in a state that is particularly easy to understand intuitively.

[Brief description of the drawings]

FIG. 1 is a block diagram of a three-dimensional image generation device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the contents of environment mapping executed in the three-dimensional image generation device shown in FIG.

FIG. 3 is a diagram for explaining the contents of mip mapping executed in the three-dimensional image generation device shown in FIG. 1;

FIG. 4 is a diagram for explaining an arrangement of image data stored in a cube memory included in the three-dimensional image generating apparatus shown in FIG. 1;

FIG. 5 is a diagram conceptually showing a memory area of a cube memory provided in the three-dimensional image generation device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Geometry part 12 Rendering part 14 Memory part 16 Display part 18 Cube memory 20, 20-1, 20-2, 20-3 Environment map 22 Displayed object 24 Gaze 26 Reflection point 28 Gaze reflection vector 30 Reference point

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B047 AA30 EB15 5B080 CA09 GA22 5C061 AA21 AB12 AB17 5C082 BA12 BA34 BA46 BB15 CA32 CA55 CB01 DA53 MM04 MM07 MM10

Claims (8)

[Claims] 1. A three-dimensional image generating apparatus for performing environment mapping for projecting a surrounding scenery on a surface of an object to be displayed, comprising a two-dimensional memory capable of specifying a memory address by specifying two-dimensional coordinates. A mipmap structure comprising a plurality of environment maps that can be used and have a memory area associated with a surface of a cube, wherein the memory includes a plurality of environment maps having a geometric ratio of 1/2 in common ratio. Each of the plurality of environment maps has image data corresponding to six images projected on each surface of the cube, and the six images included in each of the plurality of environment maps Are stored in the memory in a state of being arranged in an L-shape occupying 3/4 of a memory area having an aspect ratio of 1: 2,
In the mipmap structure environment map, the small scale environment map sequentially circumscribes the concave corners of the L-shaped memory area occupied by the large scale environment map.
2. A three-dimensional image generation device, wherein the three-dimensional image generation device is stored in the memory so as to be arranged in two memory areas. 2. The arrangement of the image data for the six images included in each of the plurality of environment maps is unified for all the environment maps, and among the plurality of environment maps, the environment map having a small scale is a scale map. 3. The three-dimensional image generating apparatus according to claim 1, wherein the image data is stored in a memory area closer to the origin (0, 0) of the memory than a memory area occupied by the large environment map. 3. The image data of six images included in each of the plurality of environment maps is stored in the memory in a state where continuity of images of five of the six surfaces of the cube is maintained. The three-dimensional image generation device according to claim 1 or 2, wherein: 4. The image data of the six images included in each of the plurality of environment maps, among the images projected on the cube, are located at the near side, the back side, the right side, and the left side in relation to the object to be displayed. The three-dimensional image generation apparatus according to any one of claims 1 to 3, wherein the four images are stored in the memory in a state where continuity of the four images is maintained. 5. A method for generating an environment map which is referred to when performing an environment mapping for projecting a surrounding scenery on a surface of an object to be displayed in a process of generating a three-dimensional image, wherein the environment map is projected onto each surface of a cube. Creating image data corresponding to the obtained six images, and a mipmap structure including a plurality of environment maps having a geometric scale of a common ratio of 1/2 based on the six image data. Creating an environment map, and specifying a two-dimensional coordinate to specify a memory address, and storing the environment map of the mipmap structure in a memory having a memory area associated with a cubic surface. The image data of six images of each of the plurality of environment maps is arranged in an L-shape occupying 3/4 of a memory area having an aspect ratio of 1: 2. Stored in said memory,
In the mipmap structure environment map, the small scale environment map sequentially circumscribes the concave corners of the L-shaped memory area occupied by the large scale environment map.
A method for generating an environment map, wherein the environment map is stored in the memory so as to be arranged in the second memory area. 6. The arrangement of the image data for the six images included in each of the plurality of environment maps is unified for all environment maps, and among the plurality of environment maps, an environment map having a small scale is a scale map. 6. The method according to claim 5, wherein the memory map is stored in a memory area closer to the origin (0,0) of the memory than a memory area occupied by the larger environment map. 7. Image data of six images included in each of the plurality of environment maps is stored in the memory in a state where continuity of images of five of the six surfaces of the cube is maintained. 7. The method for generating an environment map according to claim 5, wherein: 8. The image data of the six images included in each of the plurality of environment maps includes, among the images projected on the cube, positions at the near side, the back side, the right side, and the left side in relation to the object to be displayed. The method of generating an environment map according to claim 5, wherein continuity of the four images is maintained in the memory.