JP2000322597A - Image generation device and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image generation device which fast generates a high quality image obtained by considering a reflection effect and refraction effect in a plane having complicated ruggedness. SOLUTION: An incident vector 36 in a vertex on an anisotropic radiation plane is calculated from the position coordinates, etc., of a viewpoint (step 601). Plural anisotropic reflection vectors Li are calculated to the vector 36 (step 602). The vectors Li are decided by the material of an object and an incident angle. The reflection color and reflectance of each vector Li are calculated (step 603). The reflection colors of the respective vectors Li are combined to calculate a synthetic reflection color (step 604).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image generating apparatus and a recording medium.

[0002]

2. Description of the Related Art Recently, computer graphics (C)
The development of G) was remarkable, and various things came to be expressed on computers. In particular, graphic hardware that performs high-speed calculation of coordinate transformation and illumination processing of shape data and final image generation processing, and images stored in the frame buffer and images currently being processed by mixing processing Are synthesized at high speed. Also, CG
There is an increasing demand for not only simple drawing of an object on a computer but also more realistic drawing, for example, drawing considering reflection and refraction on the surface of the object, as well as viewpoint information and motion information.

[0003]

The description taking into account such reflection and refraction has conventionally been directed to an ideal smooth surface, and has been performed on the assumption that only one reflection vector exists for an incident vector. . However, when the surface has complicated irregularities such as a brush finish, the reflected light with respect to the incident light does not become the first place, and the image in which the reflection and refraction with respect to the surface are considered lacks reality.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an image for generating a high-quality image at high speed in consideration of a reflection effect and a refraction effect on a surface having complicated unevenness. It is to provide a generating device.

[0005]

According to the present invention, there is provided an image generating apparatus for generating a computer image, comprising: means for inputting shape information of an object; and means for inputting viewpoint information. A first image generation unit that generates an image of the object based on the shape information of the object and the viewpoint information, based on the shape information of the object, a material of the surface of the object, and the viewpoint information, Calculating means for calculating reflection information or refraction information for a plurality of reflection vectors or a plurality of refraction vectors on the surface of an object; combining the image created by the first image generation means with the reflection information or refraction information; And a second image generating means for generating an image.

According to a second aspect of the present invention, there is provided an image generating apparatus for generating a computer image, comprising: means for inputting shape information of an object; means for inputting motion information of the object; First image generating means for generating an image of the object based on the motion information; and a plurality of reflection vectors or a plurality of reflection vectors on the object surface based on the shape information of the object, the material of the object surface, and the motion information. Calculating means for calculating reflection information or refraction information for a plurality of refraction vectors; a second image for generating an image by combining the image created by the first image generation means with the reflection information or refraction information And a generation unit.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an image generation device 1 according to the present embodiment.

In FIG. 1, an image generation device 1 creates CG image data based on three-dimensional CG data read from an external storage device 2 and viewpoint information input from an external input device 3, Output to

An external storage device 2 connected to the image generating device 1 stores object information including the shape and texture of the object and light source information including the type, position, attribute, etc. ROM and the like. Further, another external storage device connected to the network can be used.

The external input device 3 is a device such as a mouse, a keyboard, and a joystick, and inputs viewpoint information such as a position for observing an object shape. The external display device 4 is a device that displays an image, such as a CRT display.

[0011] As shown in FIG.
Data reading unit 5, CG data storage unit 6, viewpoint information calculation unit 7, viewpoint information storage unit 8, first rendering processing unit 9, reflection information calculation unit 10, second rendering processing unit 11
Having. The image generation device 1 is composed of, for example, one computer.

In FIG. 1, a CG data reading section 5 reads CG data of an object from an external storage device 2 and
The data storage unit 6 stores it. In addition, the viewpoint information calculation unit 7 calculates viewpoint position coordinates and the like from viewpoint information input by the external input device 3 and stores the coordinates in the viewpoint information storage unit 8.

The first rendering processing unit 9 generates an image of the object, and the reflection information calculation unit 10 calculates reflection information on the surface of the object. The generated object image and the reflection information are combined by the second rendering processing unit 11.

The processing in each section of the image generating apparatus 1 will be described below. FIG. 2 is a flowchart illustrating an image generation process performed by the image generation device 1. In FIG.
The CG data reading unit 5 reads the object 3 from the external storage device 2.
The dimensional CG data is read and stored in the CG data storage unit 6 (Step 201).

Next, the viewpoint information calculation unit 7 calculates viewpoint position coordinates and the like from the viewpoint information input by the external input device 3 and stores them in the viewpoint information storage unit 8 (step 20).
2). The first rendering processing unit 9 performs the rendering processing of the object based on the CG data and the viewpoint information of the object in consideration of the illumination effect and the like (step 203). This rendering process is performed by the graphics hardware of the computer.

FIG. 3 is a diagram showing a car 41 as an object to be drawn, and FIG. 4 is a diagram showing rendering data in pixels 63. The CG data such as the coordinates of the car 41 is read from the external storage device 2 to the CG data reading unit 5,
It is stored in the CG data storage unit 6. The first rendering processing unit 9 performs rendering processing of the car 41 in consideration of the CG data of the car 41 and the lighting effect from the viewpoint position, the light source position, and the like.

As shown in FIG. 4, the rendering data of the pixel 63 at the end of the first rendering by the first rendering processor 9 includes pixel colors R (red), G (green),
Each component of B (blue) is (r1, g1, b1), and the alpha value (weight coefficient) is α1. In order to realize the reflection effect, α1 is usually “1.0”, but any value can be set.

Next, the reflection information calculation unit 10 calculates the reflectance and the reflection color at each vertex of the object shape (step 20).
4), the second rendering processing unit 11 renders the image processed in step 203 with the reflection effect calculated using the reflection color and the reflectance calculated in step 204 (step 205). The combined rendered image is displayed on the external display device 4 (step 206).

The reflection information calculation section 10 shown in FIG. 1 calculates a reflection color by a method described later. The second rendering processing unit 11 performs composite rendering of the calculated reflection color and the image generated by the first rendering processing unit 9.

That is, for example, when the reflection color is (r2, g2, b2) in the pixel 63 shown in FIG.
The final value of the pixel 63 at the end of the rendering processing is (α1 × r1 + α2 × r2, α1 × g1 + α2 ×
g2, α1 × b1 + α2 × b2). In this case, α2 = 1, but any value can be set as α2.

Since such a composite rendering process is performed by graphics hardware of a computer,
It is very fast. The final image created in this way is displayed by the external output device 4 shown in FIG.

Hereinafter, a method of calculating the reflection information will be described in detail. In the vehicle 41 shown in FIG. 3, for example, the wheel surface is the anisotropic reflection surface 33. The anisotropic reflection surface 33 is a surface having complicated irregularities, and is, for example, a surface having directional fine scratches such as a spin finish or a hairline finish in metal working.

FIG. 5 shows the reflected light 3 on the anisotropic reflection surface 33.
FIG. 7 is a diagram showing a reflection vector, and FIG. 6 is a diagram showing a reflection vector. As shown in FIG.
The reflected light 37 with respect to the incident vector 36 at the upper point P has a wide shape and cannot be represented by one reflected vector. This reflected light 37 is the material of the object and the incident vector 36,
That is, the shape is determined by the angle of incidence, and becomes more complicated than an ideal smooth surface.

Therefore, in the image generating apparatus 1, the shape of the reflected light 37 with respect to the anisotropic reflection surface 33 is stored in advance,
This reflected light 37 is converted into n reflection vectors Li (i = 1,
.., N, where n is an integer of 1 or more) and approximate. Here, as n is larger, the reflected light 37 is more accurately approximated.

FIG. 7 is a flowchart for calculating reflection information for the anisotropic reflection surface 33. The incident vector 3 at the vertex P on the anisotropic reflection surface 33 is determined from the position coordinates of the viewpoint 35 and the like.
6 is calculated (step 601).

Next, an anisotropic reflection vector Li for the incident vector 36 is calculated (step 602). As described above, the anisotropic reflection vector Li is determined by the material of the object and the incident vector 36, but can be generated in a program for each incident vector, or the reflection vector Li for each material and incident angle can be determined. May be held. Each reflection vector Li is normalized by a vector having the largest component.

Next, the reflection color and the reflectance of each reflection vector Li are calculated (step 603). The reflection color is a color at an intersection between the reflection vector Li and an object existing on the reflection vector Li. The object for which the intersection is to be obtained is not limited to the actually drawn object, but may be a virtual object.
For example, as shown in FIG.
When the image of the object around the car 41, that is, the texture image 45 is captured on the virtual sphere 43, the reflection color is the color of the intersection of the reflection vector Li and the virtual sphere 43.

FIG. 8 is a diagram showing an example of the reflectance W (γ) with respect to the reflection angle γ. The reflectivity differs depending on the material. The reflection angle γ is an angle between the normal vector 39 at the point P and the reflection vector.

In step 603, for example, each of the reflection vectors L1, L2, L3 shown in FIG.
The reflection color at the intersection with and the reflection vectors L1, L2, L3
The reflectance W (γ1) for the reflection angles γ1, γ2, γ3 of
W (γ2) and W (γ3) are obtained.

Next, the reflection colors of the reflection vector Li calculated in step 603 are combined (step 604), and the combined reflection color is calculated. The composite reflection color R (r, g, b) is obtained by the following equation. R (r, g, b) = 1 / nΣW (γi) × | Li | × Li (r, g, b) (1) where n is the number of reflection vector samples, W (γi)
Is the reflectance of the reflection vector Li, | Li | is the size of the reflection vector Li, and Li (r, g, b) is the reflection vector Li.
Is the reflection color.

The process of synthesizing the reflected color shown in equation (1)
This is performed by using the above-described graphics hardware included in the image generation device 1. That is, R (r, g, b)
Are α2 × r2, α2 × g2, α2 × b in FIG.
Equivalent to 2.

The second rendering processing unit 11 performs a composite rendering process on the composite reflection color obtained in this way and the image of the object obtained by the first rendering processing unit 9, and the final image is displayed on the external display device 4. .

Although the calculation processing and the composite rendering processing for obtaining the composite reflection color can be performed by a program, high-speed drawing cannot be performed because a large amount of calculation time is required. However, if graphics hardware is used as in the present embodiment, realistic drawing can be performed at high speed.

Next, a method for further enhancing the reality of image drawing will be described. FIG. 9 is a diagram showing a texture image prepared for each reflection angle. As shown in FIG. 9, when the reflection angle is close to 0 degrees, a clear texture image 4 is obtained.
5-1 is put on the virtual sphere 43, and when the reflection angle is close to 90 degrees, the blurred texture image 45-2 is put on the virtual sphere. By using a different texture image for each reflection angle, a more realistic reflection effect can be realized.

FIG. 10 is a diagram showing a texture image 45-3. In this way, by dividing the texture image 45-3 into the area A in which the image is clear and the area B in which the image is blurred, a more realistic reflection effect can be realized.
For example, a clear reflection image is pasted on the center of the object, and a blurred reflection image is pasted on the edge of the object.

As described above, according to the present embodiment, an elaborate image taking into account the reflection effect of an object including an anisotropic reflection surface is generated at high speed by using graphic hardware of a computer. It can be displayed. As a result, a high-quality image can be generated even in a personal computer having no graphic engine.

Although the position of the viewpoint 35 is input from the external input device 3 in the present embodiment, it is also possible to fix the viewpoint position and input the moving amount of the car 41 from the external input device 3. In this case, if the shape of the virtual object that captures an image is selected according to the moving amount and moving direction of the car 41, the reflection effect can be calculated more efficiently.

In the present embodiment, the reflection effect has been described. However, if a refraction color is calculated using a reflection vector as a refraction vector and a refraction index corresponding to a material is prepared, refraction information is calculated, and the composite rendering is similarly performed. It is possible to perform processing. It should be noted that the program for performing the processing shown in FIGS. 2 and 7 in the present embodiment can be stored in a recording medium such as a CD-ROM and distributed.

[0039]

As described above in detail, according to the present invention, a high-quality image can be generated at high speed in consideration of the reflection effect and the refraction effect.

[Brief description of the drawings]

FIG. 1 is an image generation apparatus 1 according to an embodiment of the present invention.
Figure showing

FIG. 2 is a flowchart illustrating an image generation process performed by the image generation device 1.

FIG. 3 is a view showing a car 41;

FIG. 4 is a diagram showing image data of a pixel 63;

FIG. 5 is a view showing reflected light 37 on an anisotropic reflection surface 33;

FIG. 6 is a diagram showing a reflection vector Li.

FIG. 7 is a flowchart of calculation of reflection information on the anisotropic reflection surface 33;

FIG. 8 is a diagram showing a reflection angle and a reflectance.

FIG. 9 is a diagram showing a texture image prepared for each reflection angle.

FIG. 10 is a diagram showing a texture image 45-3.

[Explanation of symbols]

 1 Image generating device 2 External storage device 3 External input device 4 External display device 5 CG data reading unit 6 CG data storage unit 7 View point information Calculating unit 8 View point information storing unit 9 First rendering processing unit 10 Reflection information calculating unit 11 Second rendering processing unit

Claims (8)

[Claims] 1. An image generating apparatus for generating a computer image, comprising: a unit for inputting shape information of an object; a unit for inputting viewpoint information; and the object based on the shape information of the object and the viewpoint information. First image generating means for generating an image of, based on the shape information of the object, the material of the surface of the object and the viewpoint information, reflection information for a plurality of reflection vectors or a plurality of refraction vectors on the surface of the object or Calculating means for calculating refraction information; and second image generating means for generating an image by combining the image created by the first image generating means with the reflection information or the refraction information. An image generation device characterized by the above-mentioned. 2. An image generating apparatus for generating a computer image, comprising: a unit for inputting shape information of an object; a unit for inputting motion information of the object; and based on the shape information and the motion information of the object. A first image generating means for generating an image of the object; and a plurality of reflection vectors or a plurality of refraction vectors on the object surface, based on the shape information of the object, the material of the object surface, and the motion information. Calculating means for calculating reflection information or refraction information; and second image generation means for generating an image by combining the image created by the first image generation means with the reflection information or refraction information. An image generating apparatus, comprising: 3. The first image generating means according to claim 1 or 2, wherein the first image is generated by the first image generating means, and the object information is represented by a pixel color and an alpha value. And a second image in which the reflection information or the refraction information is represented by a pixel color and an alpha value. 4. The reflection information or refraction information, wherein a virtual object having an arbitrary shape is provided around the object, and information about an intersection of the virtual object and a reflection vector or a refraction vector is provided. Alternatively, the image generation device according to claim 2. 5. The image generating apparatus according to claim 1, wherein the reflection information or the refraction information has different clarity depending on the angle of the reflection vector or the refraction vector. 6. The clarity of the reflection information or the refraction information differs according to the position of an object.
Alternatively, the image generation device according to claim 2. 7. An image generating apparatus for generating a computer image, comprising: a unit for inputting shape information of an object; a unit for inputting viewpoint information; and the object based on the shape information of the object and the viewpoint information. First image generating means for generating an image of, based on the shape information of the object, the material of the surface of the object and the viewpoint information, reflection information for a plurality of reflection vectors or a plurality of refraction vectors on the surface of the object or An image comprising: a calculation unit for calculating refraction information; and a second image generation unit for generating an image by combining the image created by the first image generation unit with the reflection information or the refraction information. A recording medium that records a program that causes a computer to function as a generation device. 8. An image generating apparatus for generating a computer image, comprising: a unit for inputting shape information of an object; a unit for inputting motion information of the object; and based on the shape information and the motion information of the object. A first image generating means for generating an image of the object; and a plurality of reflection vectors or a plurality of refraction vectors on the object surface, based on the shape information of the object, the material of the object surface, and the motion information. Calculating means for calculating reflection information or refraction information; and second image generation means for generating an image by combining the image created by the first image generation means with the reflection information or refraction information. A recording medium on which a program for causing a computer to function as an image generation device is provided.