JPS63254583A - Light beam tracking image generating device - Google Patents

Abstract

PURPOSE:To put a crossing decision part and a brightness calculation part in parallel operation and to shorten an image generation time by providing a brightness accumulation part which obtains brightness of each picture element from a brightness calculation part and a picture element memory and integrates it, and writes the result in the picture element memory again. CONSTITUTION:The brightness calculation part 13 calculates the brightness at an intersection from body; data on the color, reflection coefficient, transmission coefficient, etc., of a body. When reflection and transmission processing is not required, a picture element number and the calculated brightness are outputted to the brightness accumulation part 14 and when the reflection and transmission processing is required, the intersection with the body is set as a view point to recalculate light beam, which is outputted to a light beam data buffer 11. The brightness accumulation part 14 adds the brightness inputted from the brightness calculation part 13 to the brightness of the same picture element stored in the picture element memory 15 and writes the result in the picture element memory 15. An image generation control part 16 controls the light beam data buffer 11 and outputs the light beam data to the intersection decision part so that the intersection decision part 12 operates effectively. Consequently, the intersection decision part 11 process the input from the light beam buffer 11 in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a ray tracing image generation device that generates three-dimensional images.

BACKGROUND OF THE INVENTION In recent years, ray tracing image generation devices are considered to be the devices that can generate the most realistic images in the field of three-dimensional computer graphics. An example of the device will be described. FIG. 2 shows the principle of a conventional ray tracing image generation device. In FIG. 2, 21 is a viewpoint, 22 is a display screen, 23 is a pixel, and 24 and 25 are objects. Considering a straight line connecting the viewpoint 21 and the display surface 22, the light ray 26 that enters the viewpoint 21 from that direction is traced in the opposite direction to find the incident intensity. That is, the brightness at a certain pixel is expressed by the following formula based on Whitte's light source model (for example, IEICE Transactions V
o1. J6B-D No., pages 4733-740).

0: Ambient light coefficient.

K, random reflection coefficient.

θ: Angle between the incident direction and the normal line.

L: Number of light sources.

Ko: Metal reflection coefficient.

n: Metal reflection index.

θ1: Angle between the reflection direction and the line of sight.

Ks Two reflection coefficients.

K: transmission coefficient.

S: Brightness due to reflected light.

T: Luminance due to two transmitted light.

Here, the luminance ■ is a vector having R, G, and B3 configurations. In the above equation, the first term represents the ambient light, the second term represents the scattered reflected light, the third term represents the metal reflected light, the fourth term represents the reflected light, and the fifth term represents the brightness due to the transmitted light.

FIG. 3 shows a conventional example based on the principle of the above-mentioned ray tracing image generation device. The operation will be explained below.

First, based on the light ray data inputted by the image generation control section 31, the intersection determination section 32 determines the intersection between the light ray and the object. The ray data consists of the position of the ray, the direction of the ray, the pixel number, and the attenuation rate of the ray. Next, the brightness calculation accumulator 33 performs brightness calculation based on the above-mentioned step 2. Here, if the intersection does not have reflection or transmission attributes,
Output the result to pixel memory. However, if it has reflection or transmission attributes, the intersection point is virtually regarded as a viewpoint, and the intersection judgment for the virtual viewpoint in the reflection or transmission direction is performed.
The intersection determination unit 32 repeats brightness calculation and accumulation.
The accumulation unit 33 performs the calculation, and outputs the data to the pixel memory 34 after completion.

Problems to be Solved by the Invention However, with the above configuration, it is not possible to start determining the intersection of light rays for the next pixel until the luminance calculation and accumulation for a certain pixel are completed. However, there is a problem in that only one of the luminance calculation/accumulation section 33 is in operation.

In view of the above problems, the present invention provides a ray tracing image generation device that executes intersection determination and brightness calculation in parallel and generates images at high speed.

Means for Solving the Problems In order to solve the above problems, the ray tracing image generation device of the present invention includes a ray data buffer that stores ray data;
A brightness calculation unit that calculates brightness and feeds back data that requires transmission or reflection processing to the ray data buffer, and a brightness accumulation unit that obtains the brightness of each pixel from the brightness calculation unit and pixel memory, accumulates it, and writes it back to the pixel memory. It has a structure that includes a calculation section.

Operation The present invention can operate the intersection determination section and the brightness calculation section in parallel with the above-described configuration.

EXAMPLE Hereinafter, a ray tracing image generation device which is an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a ray tracing image generation device in an embodiment of the present invention. The operation of the configuration of this embodiment will be explained below.

In FIG. 1, a ray data buffer 11 buffers initial ray data and ray data fed back from the brightness calculation unit 13, that is, ray data that requires reflection or transmission processing at an intersection with an object, and stores it in an intersection determination unit. 1
Each time the second process is completed, the next ray data is output to the intersection determination section 12. The light beam data includes the position of the light beam, the direction of the light beam, the pixel number at the intersection of the light beam and the display screen 22,
and the attenuation rate of the light beam. The intersection determination unit 12 determines whether the light ray and the object intersect based on the given light ray data and pre-existing position data of the object, and outputs the result to the brightness calculation unit 13. The brightness calculation unit 13 calculates the brightness at the intersection point from object data such as the color of the object, the reflection coefficient, and the transmission coefficient. If reflection/transmission processing is not required, the pixel number and the calculated brightness are output to the brightness accumulator 14. If reflection/transmission processing is required, the ray data is recalculated using the point of intersection with the object as a viewpoint, and is output to the ray data buffer 11. The reflection/transmission process is repeated until the intensity of the light beam falls below a certain value.

The luminance accumulating unit 14 accumulates the luminance manually input from the luminance calculating unit 13 to the luminance of the same pixel stored in the pixel memory 15, and writes the accumulated luminance to the pixel memory 15 again.

The image generation control unit 16 controls the light beam data buffer 11.
'IIIL, output ray data to the intersection determination section so that the intersection determination section 12 operates effectively.

As a result, the intersection determination unit 11 does not need to wait for processing for the next pixel until the luminance calculation and accumulation of a certain pixel are completed as in the conventional case, and can process the input from the ray data buffer 11 in parallel. Can be done.

Effects of the Invention As described above, the present invention has a light beam data buffer that stores light data, a brightness calculation unit that calculates brightness and feeds back data that requires transmission or reflection processing to the light data buffer, and a brightness calculation unit that calculates the brightness of each pixel. By providing a brightness accumulation unit that obtains information from the brightness calculation unit and pixel memory, accumulates it, and writes it back to the pixel memory, the intersection determination unit and the brightness calculation unit can operate in parallel, reducing image generation time. be able to.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a ray tracing image generation device according to an embodiment of the present invention, FIG. 2 is a principle diagram of a conventional ray tracing image generation device, and FIG. 3 is a block diagram of a conventional ray tracing image generation device. be. 11... Ray data buffer, 12...
- Intersection determination unit, 13... Brightness calculation unit, 14...
...Brightness accumulator, 15...Pixel memory, 1
6... Image generation control section. Agent's name Patent attorney Toshio Nakatashi Idiot 1 person is trivial 2I - - Viewpoint 22 - Display 1 page 23 - Image Not yet 242S - Buttai 26 - Human radiation calculation i2 figure

Claims (1)

[Claims] A ray data buffer that accumulates ray data, an intersection determination unit that determines the intersection of an object and a ray, a brightness calculation unit that calculates brightness and feeds back data that requires transmission or reflection processing to the ray data buffer, a pixel memory that stores the luminance of each pixel for each pixel; a luminance accumulating unit that obtains and accumulates the luminance of each pixel from the luminance calculation unit and the pixel memory and writes it back to the pixel memory; and an image generation control that controls the flow of light beam data. A ray tracing image generation device having a section.