JP4493401B2 - 3D computer graphic display system and program - Google Patents

Description

The present invention relates to a 3D computer graphic display system and a program .

  Conventionally, in order to draw a 3D computer figure realistically like a photograph, light source information is set in the 3D computer figure, and color information and brightness information are calculated and displayed for each pixel by radiosity processing. Yes.

  However, since radiosity processing requires enormous time for calculation, there is a problem that even if a high-performance computer is used, it is not practical to do this at the stage of actually displaying a three-dimensional computer graphic with a browser. It was.

The present invention has such has been made in view of the conventional technical problem, pre performs radiosity process requiring a lot of time to calculate and generate polygon data embedded as the color information for each vertex , and to provide a 3D computer graphics display system, and a program is possible to change the brightness of the light source from the generated polygon data to reproduce the radiosity quality image possible.

The 3D computer graphic display system according to the first aspect of the present invention is a radiosity processing unit that performs radiosity processing on primitive three-dimensional computer graphic data including a plurality of light sources , and a vertex from the radiosity processing result of the radiosity processing unit. Polygon data generation means for generating a large number of polygons having coordinate information and color information and storing them in the storage means, external interface means for accepting input of light source coordinates, color light and brightness setting information, and the external interface means accepting The color light and brightness of the corresponding light source is set based on the setting information of the coordinates, color light and brightness of the light source, and the influence degree of the light of the set light source is set for each vertex of each of the many polygons generated by the polygon data generating means Is assigned as color information at the corresponding vertex position, and for each vertex of the polygon Data processing means for adding color information and color information of the assigned light source, and generating color information of the addition result as vector data together with vertex coordinate information for each vertex of each polygon, and each of the data processing means generated Rendering processing means for rendering 3D computer graphics by rendering vector data of the color information of the addition result together with vertex coordinate information for each vertex of the polygon, and display means for displaying the 3D computer graphics are provided.

According to a second aspect of the present invention, in the 3D computer graphic display system according to the first aspect , the rendering processing means performs a walk-through display process .

According to a third aspect of the present invention, there is provided a 3D computer graphic display program that performs radiosity processing on primitive three-dimensional computer graphic data including a plurality of light sources, and vertex coordinate information and color information based on the result of the radiosity processing. a polygon data generation processing to be stored in the generated and the storage means a plurality of polygon with coordinates of a light source, inputs and acceptance Ru input acceptance processing of the color light and brightness setting information, the light source received in the input reception processing The light source attribute setting process for setting the color light and lightness of the corresponding light source based on the coordinate, color light and lightness setting information, and the light source attribute setting process for each vertex of a large number of polygons generated by the polygon data generation process. A light source influence assignment process for assigning the light influence of the light source set as color information at the corresponding vertex position; By adding the color information of the light source allocation Gon color information of each vertex and at the light source influence the allocation process to generate color information of the addition result as vector data together with the vertex coordinate information for each vertex of each polygon The computer executes data processing and rendering processing for rendering vector data of the color information of the addition result together with vertex coordinate information for each vertex of each polygon generated by the data processing to generate a 3D computer graphic and displaying it on the display means This is characterized in that it is executed.

According to a fourth aspect of the present invention, in the 3D computer graphic display program according to the third aspect , a walk-through display process is performed in the rendering process .

According to the 3D computer graphic display system and program of the present invention, a radiosity process is performed on a primitive 3D computer graphic created by 3D computer graphic creation software, and a large number of polygons having vertex coordinate information and color information are further processed. 3D computer graphic data is generated by performing polygon data generation processing to generate a light source, a light source is set for rendering processing for the 3D computer graphic data, and light from the light source is applied to each vertex of a large number of polygons. The color information for each vertex of each polygon and the color information for the light from the light source allocated by the light source influence allocation process are added to each polygon. Together with the vertex coordinate information, the color information of the addition result is vector-decoded. Data, and using this vector data to display a three-dimensional computer figure in which the influence of light from the light source is changed is displayed on the display. While reducing the number and thus the computing time of the computer, it is possible to draw a three-dimensional computer figure in which the influence of the light from the light source is changed at high speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a display 3D computer graphic generation apparatus 100 according to the present invention, 3D computer graphic display software 200 for performing rendering processing described later on polygon data (3DX) 110 generated by the display 3D computer graphic generation apparatus 100, and A relationship with the browser 300 that operates a 3D computer graphic in cooperation with the 3D computer graphic display software 200 and performs walk-through and animation display is shown.

  The display 3D computer graphic generation device 100 is a computer, and a display 3D computer graphic generation program for generating polygon data 110 described later is installed. As shown in FIG. 2, the display 3D computer graphic generation device 100 performs, as a functional component, a source 3DCG generation unit 1 that generates a source three-dimensional computer graphic, and performs radiosity processing on the source 3D computer graphic. Furthermore, a polygon data generation unit 2 and a data storage unit 3 for generating a large number of polygons are provided. A display device 4 and an input device 5 are connected as an HMI interface.

  The primitive 3DCG creation unit 1 executes a three-dimensional computer graphic creation software to create a primitive three-dimensional computer graphic. For example, when creating indoor polygon data, floors, walls, ceilings, windows, furniture, etc. 3 by processing and combining simple 3D graphics such as boards and boxes, rotating 2D graphics, extrusion, sweeping, etc. Create a 3D computer figure and add appropriate attribute names such as “flooring”, “carpet”, “tatami” to the polygons with specific properties of each 3D computer figure, for example, for floors. The data is stored in the data storage unit 3.

  As shown in FIG. 3, the polygon data generation unit 2 includes a radiosity processing unit 21, a polygon cutout unit 22, and a polygon data storage unit 23. The radiosity processing unit 21 sets the color tone, texture, and the like for each attribute for the three-dimensional computer graphic information created by the original 3DCG creation unit 1 and stored in the data storage unit 3, and will be described later. Radiosity processing is performed to obtain primitive radiosity data. The polygon cutout unit 22 cuts out a large number of triangular polygons from a three-dimensional computer graphic stored in the data storage unit 3 and also provides color information for each of the three vertices of each polygon with the vertex coordinate information for the original radiosity data. Then, the data is stored in the data storage unit 3 as vector data by the polygon data storage unit 23. At this time, the influence of each light source is calculated individually, and the identification information of the affected light source is set for each vertex together with the color information.

  The 3D computer graphic display software 200 renders display 3D computer graphic data (3DX) 110 composed of polygon data generated by the display 3D computer graphic generation device 1 and causes the display device 11 to display the rendered data. The program executes a light source brightness change process, a walk-through display process, and an animation display process in response to an operation from the browser 300. As shown in FIG. 4, when the 3D computer graphic display software 200 is divided into functional configurations, the external interface unit 6 that transmits / receives data to / from the browser 300 and the external command received by the external interface unit 6 are supported. Thus, a data processing unit 7 that performs appropriate processing on the 3DX data 110 and a rendering processing unit 8 that performs rendering processing are provided.

  The browser 300 is HTML software such as Internet Explorer (trade name) of Microsoft Corporation, Netscape (trade name) of Netscape Corporation, and Opera (trade name) of Opera Software ASA. The external interface unit 6 of the 3D computer graphic display software 200 provides the browser 300 with the function setting content 15 and the parameter setting content 16 and uses the input device 12 for the user to set the light source brightness information setting operation 31 and animation. A control operation 32 is performed, and a 3DX file designation operation 33 and various setting operations 34 are performed.

  It should be noted that computer systems that execute the software 200 and 300 include OpenGL, DirectX, and the like in order to display the display device 4 at high speed using drawing data from the rendering processing unit 6 of the 3D computer graphic display software 200. A video graphic card 13 for operating the 3D rendering engine API at high speed is mounted.

  The 3D computer graphic display software 200 and the browser 300 cooperate to execute the following rendering process. As shown in FIG. 5, the light source brightness setting function is called from the function setting content 15 on the browser 300 side, the light source brightness setting operation is performed, and the light source brightness setting information is transmitted to the 3D computer graphic display software 200 to display the 3D computer graphic display. The external interface unit 6 of the software 200 acquires the light source brightness setting information (step S31).

  The external interface 6 passes the acquired light source brightness setting information to the data processing unit 7, and the data processing unit 7 changes the light source table by a process to be described later (step S32). In this process, the lightness index for each light source is determined based on the lightness index for each light source, for example, an index indicating that the brightness at the time of generation of primitive radiosity data is 100%, and the brightness has been reduced to 50% or 150%. Reset for each vertex of each polygon affected by the light source.

  The index for the light source (1) at a certain vertex of a polygon based on the primitive radiosity data is set to 100%. For example, if the light source (1) becomes darker than the original and the brightness is reduced to 50%, The brightness of the vertex with respect to the light source (1) is reduced to 50%.

  Polygon data is recalculated using the changed light source table data and passed to the rendering processing unit 8 (step S33). This polygon data recalculation refers to the changed light source table data, and recalculates vector data for each polygon reflecting the influence index for each reset light source.

  The rendering processing unit 83 renders the recalculated vector data, passes it to the browser 300, and displays it on the screen of the display device 11 as a three-dimensional computer graphic (step S34).

  Next, display 3D computer graphic creation processing by the 3D computer graphic creation apparatus 100 having the above-described configuration, and rendering operation by the 3D computer graphic software 200 and the browser 300 will be described.

<Radio City>
Radiosity is “a technique that determines the brightness of a surface by calculating the interaction between light striking an object in a three-dimensional space and the reflected light of each object”. More specifically, it refers to the idea that “the brightness of one minute patch (polygon) is the sum of its own brightness and the brightness coming from another minute patch (polygon)”. This is a so-called radiosity equation.

  However, Bi is how much energy the i-th patch emits per unit area and unit time (radiosity), Ei is the emission energy of the i-th patch itself, and ρi is the i-th patch coming from others Aj is the area of the jth patch, Bj is the radiosity of the jth patch, and Fij is how much energy from the jth patch reaches the ith patch ( (Form factor).

Solve this equation and use Bi for the brightness of the patch. In that case,
(A) The radiosity of the jth patch is required to determine the radiosity of the ith patch, and conversely, the radiosity of the ith patch is required to determine the radiosity of the jth patch, This equation cannot be solved as it is,
(B) how to calculate the form factor,
There are two problems.

<Progressive refinement>
As a technique for solving the above problem (a), a method called progressive refinement is used. This is an iterative process as follows.

(I) As an initial state, it is assumed that the radiosity Bi of all patches consists only of its own emission energy Ei. Also, assume a radiosity bi that is the same size as Bi, radiates energy once to another patch, and then becomes zero.

  (Ii) Among all the patches, the patch having the largest energy bi × Ai radiated to other patches is selected.

(Iii) The energy of the selected patch is radiated to all other patches. At this time, all other patches receive this energy and the radiosity increases according to the radiosity equation. Moreover, bi becomes 0 according to (i).

  (Iv) Return to (ii) and repeat the process. Repeat until all patches have been processed or bi x Ai is less than a certain value.

  This progressive refinement is known to be an excellent method of rapid convergence because the energy radiated to other patches of the patch selected each time it is repeated becomes smaller. However, it is necessary to make the patches sufficiently fine to obtain good results, and it takes a lot of time to process all the patches (on the order of hundreds of thousands even in a standard room model).

<Form factor>
Next, the form factor is described. The energy reaching the minute area dAj on the patch j from the minute area dAi on a certain patch i is expressed as follows.

  Where dEi is the energy per unit area radiated from patch i, dAi is the minute area on patch i, dAj is the minute area on patch j, Ii is the brightness of patch i, and θi is the normal vector of dAi And dAj normal vector, dωij is the solid angle of dAj viewed from dAi, θj is the angle between the vector connecting dAi and dAj and the normal vector of dAj, r is the length of the vector connecting dAi and dAj is there.

On the other hand, it is considered that energy is diffused from a certain point on the patch i in a hemispherical shape, and the total amount is expressed as follows.

  Where dω is a small solid angle, dEi is the energy of light passing through dω, Ii is the brightness of patch i, and θ is the angle from the hemispherical zenith of dω.

Therefore, these ratios are as follows.

This form factor is “how much energy from the j-th patch reaches the i-th patch”. In order to integrate this with i and j to obtain a value per unit area, Ai Divide by to get the form factor.

This form factor has the following geometric meaning: When the patch Aj is viewed from the minute area dAi of the patch i, the area ωij obtained by projecting the patch Aj onto the unit hemisphere (hemisphere) centering on dAi is as follows.

  Where θj is the angle between the vector connecting dAi and the center of Aj and the normal vector of Aj, and r is the length of the vector connecting the center of dAi and Aj.

Furthermore, when this is projected onto a unit circle centered on dAi, the area is

Therefore, the ratio of the unit circle to the area π is

It turns out that this is the integrand of the form factor itself. This is called Nusselt's similarity, but the work of finding the form factor by this is from the physical and abstract thing “how much energy from the j-th patch reaches the i-th patch”. The j-th patch can be reduced to a geometrical and concrete one by projecting the j-th patch to a hemisphere centered on the i-th patch and further to the unit circle to obtain the ratio of the area of the unit circle.

  Here, a semi-cube (hemi cube) including a unit hemisphere centered on the i-th patch as shown in FIG. 6 is considered. It is obvious from FIG. 6 that the same result as Aj can be obtained by projecting patch Aj onto this hemi-cube to create Aj ', and projecting this Aj' onto a hemisphere and further onto a unit circle. In other words, Aj ′ is used instead of Aj in Equation (3), and cos θj and r are also changed in accordance with Aj ′.

  Projecting a patch on a hemicube is nothing more than placing a camera with a 90-degree viewing angle at the center of the i-th patch and rendering it up, front, back, left, right, a total of 5 times, As a result, the form factor of only the visible patch from the i-th patch can be calculated using the hardware drawing support function of the graphic card depending on the environment.

  It is meaningless if you can not distinguish which pixel each pixel of the rendered image comes from, but there is a method to set the patch number as the color of the patch in advance, pixels such as `` glReadPixels '' from the rendered image A patch number is acquired as a pixel color using a data acquisition function, and since it is a cube, simple geometric elements such as cos θi, cos θj, and r may be calculated and added for each patch.

  When combined with the above-mentioned progressive refinement, the process up to here corresponds to one loop, and the process is repeated until convergence.

  The radiosity processing unit 21 performs the above processing to generate primitive radiosity data and stores it in the data storage unit 3.

<Polygon data generation>
The calculation of the radiosity requires a great amount of time, and it is not realistic to perform the calculation with a player who freely walks around the virtual space. So, if you get the primitive radiosity data, cut out polygons (corresponding to the patches described so far) from this primitive radiosity data, and coordinate information for each vertex of each polygon and color information for each vertex. And stored in the data storage unit 3 as vector data for each of a large number of polygons. In this color information, the influence of each light source set in the three-dimensional computer graphic is individually calculated, and the index is also included in the vector data as polygon data, so that the light control at the time of execution described later is possible.

  7 to 9 show the polygon data cut-out and vector data. As shown in FIG. 7, polygons are cut out from the radiosity data of the original three-dimensional computer graphic. For example, the triangular polygons A and B have their vertices (a1, a2, a3); (b1, b2, b3), and the coordinates of the vertices are (a1: Xa1, Ya1, Za1); (a2: Xa2, Ya2). , Za2); (b1: Xb1, Yb1, Zb1); (b2: Xb2, Yb2, Zb2); Furthermore, the color information of each vertex is obtained from the radiosity data by RGB for each diffuse and specular, for example, from the light source 1 for the vertex a1 of the polygon A (DRa11, DGa11, DBa11, SRa11, SGa11, SBa11), (DRa12, DGa12, DBa12, SRa12, SGa12, SBa12), and from the light source 3 (DRa13, DGa13, DBa13, SRa13, SGa13, SBa13), and the like. Similarly, the vertex a2 is, for example, (DRa21, DGa21, DBa21, SRa22, SGa22, SBa22) or the like. FIG. 9 exemplifies primitive radiosity vector data of a polygon A having three vertices a1, a2, and a3.

  When radiosity is set, a polygon having an attribute starting with a specific character is regarded as a light source. For example, “rad” is a point light source, “rad?” Is a parallel light source, and “rad ??” is a spot light source. And the degree of influence on each of the other polygons is taken into account accordingly. Further, as shown in FIG. 10, the brightness of the diffuser (diffuse light) and specular (specular light) of the light source are set in the same manner as in a normal material. The spot angle of the spot light source is set by glossiness. In addition, when setting the influence level of the light source, the brightness of the entire scene (background brightness), ambient, and the like are also set.

<Rendering process>
The 3D computer graphic display software 200 executes processing for displaying on the browser 300 the display 3D computer graphic data 110 that is the three-dimensional virtual space data created by the polygon data generation unit 2. The software 200 not only reads the 3D computer graphic data for display 110 that is polygon data and displays it in a three-dimensional manner, but also displays it on the screen of the display device 11 by the browser 300 by operating the pointing device that is the input device 12. Events such as walking around in the virtual space, playing a specific operation in the virtual space, and playing an animation can be generated. The table in FIG. 11 shows main parameters that can be used in the 3D computer graphic display software 200, and the table in FIG. 12 shows functions for external control that can be operated and set from the browser 300.

  The display 3D computer graphic data 110, which is primitive radiosity data, also includes color information of the vertices of polygons as described above. As described above, this color information includes two components of diffuses (diffuse light) and specular (specular reflection light).

  First, rad, rad ?, which are preset as light source names as names. Or rad? ? Look for the radiosity light source that begins with and set it on the table. For example, one radiosity light source table is as shown in the table of FIG. The light source intensity is 0 to 100, and 100 is set as an initial value. In the embodiment, eight light sources from 0 to 7 can be set. This number is not particularly limited, and can be increased or decreased depending on the performance of the arithmetic processing unit.

  As shown in the table of FIG. 14, the data is held in the light source buffer and the polygon vertex color buffer. When the polygon data file of the display three-dimensional computer graphic data 110 is loaded, the light source data is first read and set in the light source buffer.

  At the time of rendering, the actual vertex color is calculated by adding the vertex colors in the vertex color buffer of each polygon in consideration of the effective light source intensity. As shown in FIG. 15, light source information is calculated for the color information of the primitive polygon vector data for each light source and for each vertex of a large number of polygons. For example, if the diffuser at the vertex (0) is affected only by the light sources (0) and (1), it is calculated as shown in FIG. 16 to obtain final color information. Rendering is similarly performed for specular. Rendering is performed in two stages. After the integration process with the texture by the diffuses is performed in the first stage, the addition process by the specular is performed in the next stage. As with many modern graphics display devices, if you have the function to perform this two-stage rendering in one pass, you can perform the rendering in one pass. Similar results are obtained. FIG. 17 shows the rendering result. FIG. 18 shows a flowchart of the rendering process.

<Runtime dimming>
The 3D computer graphic represents the virtual indoor space, and the primitive radiosity data represents the indoor state during the day, and there is a demand for expressing the virtual indoor space at sunset using this. Suppose there was. In this case, when the outside light becomes dark at sunset, it is necessary to reduce the brightness of the light from the window, that is, the light from the window as the light source. In such a case, for example, as shown in FIG. 19, a light source selection box 311 and a brightness adjustment button 312 are displayed on a screen 310 displayed by the browser 300, and a mouse or the like as the input device 12 is displayed to the user. It can be set by selecting the light source and setting the brightness by operating the pointing device. The display screen on the browser 300 is displayed by HTML shown in FIG.

  As a result, the 3D computer graphic display software 200 searches for a light source having the name from the radiosity light source table, and changes its intensity to a designated value. For example, when the light source of Light 0 is set to be reduced to 15%, a calculation process for reducing the original luminance from the corresponding light source to 15% is executed for the color information of each polygon of the original polygon data. As a result, the vertex group affected by the light from the light source can reduce the influence from the light source to 15%, and the rendering result reflects it. In the previous example, the result shown in FIG. 21 is obtained for the vertex (0).

  As described above, according to the 3DCG system using the 3D computer graphic creation device 100, the 3D computer graphic display software 200, and the browser 300 according to the present embodiment, the 3D computer graphic creation device 100 creates the radiosity once. The 3D computer graphic that reflects the influence of the light source whose brightness changes without repeating the radiosity processing can be displayed at a high speed with respect to the display 3D computer graphic 110 obtained in this way. Since the displayed 3D computer graphic data 110 is used to display a 3D computer graphic, it is possible to display a precise 3D space graphic even in animation display. In addition, it is easy to change the brightness of each light source.

1 is a block diagram showing a three-dimensional (3D) computer graphic creation device, three-dimensional (3D) computer graphic display software, and a browser according to an embodiment of the present invention. The functional block diagram of the 3D computer graphic production apparatus of the said embodiment. The functional block diagram of the polygon data preparation part in the 3D computer graphic production apparatus of the said embodiment. Functional block diagram of the 3D computer graphic display software and browser of the above embodiment. Explanatory drawing which shows the mutual function between 3D computer graphic display software of the said embodiment, and a browser. Explanatory drawing of a radiosity process. Explanatory drawing of the polygon data generation process by the said embodiment. Explanatory drawing of the polygon data produced | generated by the polygon data production | generation part in the said embodiment. Explanatory drawing of the polygon vector data in the said embodiment. Explanatory drawing of the polygon data generation operation screen in the said embodiment. A table of parameters used in the 3D computer graphic display software of the above embodiment. A table of public functions used in the 3D computer graphic display software of the above embodiment. A table of light source data obtained by the 3D computer graphic display software of the above embodiment. A table of light source buffers and vertex color buffers obtained by the 3D computer graphic display software of the above embodiment. Explanatory drawing of the color information calculation method of the vertex of the polygon which considered the influence by the light source by 3D computer graphic display software of the said embodiment. The table of the color information calculation result of the vertex of the polygon which considered the influence by the light source by 3D computer graphic display software of the said embodiment. Explanatory drawing of the three-dimensional computer figure after the rendering by 3D computer figure display software of the said embodiment. The flowchart of the color information calculation method of the vertex of the polygon which considered the influence by the light source by 3D computer graphic display software of the said embodiment. Explanatory drawing of the light control operation screen by 3D computer graphic display software of the said embodiment. Explanatory drawing of HTML of the light control operation screen which the browser of the said embodiment displays. The table of the color information calculation result after the light control of the vertex of the polygon by 3D computer graphic display software of the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3DCG preparation part 2 Polygon data generation part 3 Data storage part 4 Display apparatus 5 Input device 6 External interface part 7 Data processing part 8 Rendering process part 11 Display apparatus 12 Input device 13 Video graphic card 15 Function setting part 16 Parameter setting part 21 Radiosity processing unit 22 Polygon cutting unit 23 Polygon data storage unit 100 3D computer graphic generation device 110 3D computer graphic data for display 200 3D computer graphic display software 300 Browser

Claims (4)

Radiosity processing means for performing radiosity processing on primitive three-dimensional computer graphic data including a plurality of light sources ;
From radiosity processing result of the radiosity processing unit, a polygon data generating means for storing the generated and the storage means a plurality of polygons having vertices coordinate information and color information,
External interface means for accepting input of coordinates of the light source, color light and brightness setting information;
The color light and lightness of the corresponding light source are set based on the light source coordinates, color light and lightness setting information received by the external interface means, and the set values are set for each vertex of a large number of polygons generated by the polygon data generating means. The degree of influence of light from the light source is assigned as color information at the corresponding vertex position, the color information for each vertex of the polygon is added to the color information of the assigned light source, and the vertex coordinate information for each vertex of each polygon is added. Data processing means for generating color information of the addition result as vector data;
Rendering processing means for rendering 3D computer graphics by rendering vector data of the color information of the addition result together with vertex coordinate information for each vertex of each polygon generated by the data processing means;
A 3D computer graphic display system comprising display means for displaying the 3D computer graphic. The 3D computer graphic display system according to claim 1, wherein the rendering processing unit performs a walk-through display process . Radiosity processing for performing radiosity processing on primitive three-dimensional computer graphic data including a plurality of light sources;
From the result of the radiosity processing, polygon data generation processing for generating a large number of polygons having vertex coordinate information and color information and storing them in storage means;
Coordinates of the light source, an input acceptance processing enter Ru accepting color light and brightness setting information,
A light source attribute setting process for setting the color light and the lightness of the corresponding light source based on the coordinates of the light source, the color light and the lightness setting information received in the input receiving process ;
For each vertex of a large number of polygons generated by the polygon data generation process, a light source influence degree assigning process for assigning the influence degree of the light of the light source set by the light source attribute setting process as color information at the corresponding vertex position;
The color information for each vertex of each polygon is added to the color information for the light source assigned in the light source influence assignment process, and the color information of the addition result is generated as vector data together with the vertex coordinate information for each vertex of each polygon. Data processing,
Rendering the vector data of the color information of the addition result together with the vertex coordinate information for each vertex of each polygon generated by the data processing to generate a 3D computer graphic, and causing the computer to execute a rendering process for displaying on the display means 3D computer graphic display program characterized by the above . 4. The 3D computer graphic display program according to claim 3, wherein a walk-through display process is performed in the rendering process .

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