JPH0689090A - Three-dimensional graphics display device - Google Patents

Abstract

PURPOSE:To provide the three-dimensional graphics display device which displays a synthesized image as it is by providing the device with the functions of an accumulation buffer and image buffers. CONSTITUTION:This three-dimensional graphics display device is provided with a frame buffer 19a of double buffer constitution which has respectively two sets of the image buffers 12, 13a storing color information in correspondence to the color information and depth information and Z buffers 14, 15a storing the depth information and alternately executes plotting and displaying. The above-mentioned image buffer 13a on one side and a Z buffer 15a are connected to constitute the accumulation buffer storing the synthesis result of the plural images.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional graphics display device.

[0002]

2. Description of the Related Art In a three-dimensional graphics display device, display information is drawn in an image buffer and a Z buffer. That is, color information (image information: I value,
(Displayed in RGB) and depth information (Z direction information: Z value) are provided, the Z value is compared at the time of drawing, and if it is before the image buffer and the figure already drawn in the Z buffer, the image buffer and the Z buffer are displayed. Is rewritten, and if not, the pixel is controlled not to be rewritten.

This is called "Z buffer hidden surface elimination" and is the basis of drawing control of a three-dimensional graphics display device. Generally, an image buffer that stores I values and a Z buffer that stores Z values are set together and called a frame buffer or a frame memory (in the case of two-dimensional display, only the image buffer).

The image buffer and the Z buffer can be drawn and displayed as long as there is an area for one screen. However, in order to display like a moving picture, an area for two screens is prepared and drawn / displayed alternately. By doing so, smooth movement can be realized. Such a configuration is called a double buffer configuration.

Also, to express dynamic movements,
In a 3D graphics display device that provides high-performance functions for expressing a realistic feeling, an image once drawn in the image buffer is processed to create a blurred image or afterimage by blurring operation, or to cast an image. Then, it has an accumulation buffer for storing the result of combining a plurality of images created therein.

For this purpose, for example, the position of the image drawn in the image buffer is moved at regular time intervals, the predetermined image is multiplied, and the resulting image is subjected to arithmetic processing with the accumulation buffer. Do the operation.

Further, the bit length of the accumulation buffer needs to have more bits forming a pixel than the original image buffer depending on the number of additions. For example, if the original image is composed of 24 bits of 8 bits for each RGB, a 48-bit accumulation buffer of 16 bits for each RGB is required in order to prevent overflow even if added up to 256 times.

FIG. 3 shows an example of a block diagram of a frame buffer of a conventional three-dimensional graphics display device. In the figure, a drawing / control unit 11 writes drawing information in an image buffer A12, an image buffer B13, a Z buffer A14, a Z buffer B15, and an accumulation buffer 16 according to display data. The drawing / control unit is composed of a microprocessor, a memory, an image processing program stored in the memory, a floating point arithmetic circuit, and the like.

An image buffer A 12 holds image information to be displayed, and is a memory having a 24-bit bit length of 8 bits for each of RGB for a screen size (2K × 1K). is there. An image buffer B 13 is a memory that holds image information to be displayed alternately with the image buffer A 12.

A Z buffer A 14 stores depth information of the image drawn in the image buffer A 12, and is provided for the number of pixels (2K × 1K). The depth information is information indicating the position in the depth direction of the screen and is represented by 24 bits.

Reference numeral 15 denotes a Z buffer B, which stores depth information of the image drawn in the image buffer B13, and is provided to display the image buffer B13 alternately with the image buffer A12.

Reference numeral 16 denotes an accumulation buffer, which is a memory for storing a result obtained by processing an image once drawn in the image buffer and synthesizing a plurality of images created therein.

A multiplexer (hereinafter abbreviated as MPX) 17 selects either the image buffer A12 or the image buffer B13 and outputs the output to the display unit 18. A display unit 18 displays an image.

A frame buffer 19 includes an image buffer A12, an image buffer B13, and a Z buffer A.
14, Z buffer B15, accumulation buffer 16
It is composed of

The operation of the three-dimensional graphics display device shown in the figure will be described. When performing a moving image display, the drawing / control unit 11 first draws in the image buffer A12, and after the drawing is completed, the MPX 17 supplies the output of the image buffer A12 to the display unit 18 for display. Next, the drawing / control unit 11 draws in the image buffer B13, and after drawing is completed, M
The output of the image buffer B13 is supplied to the display unit 18 and displayed by the PX17. Then, the image is again drawn and displayed in the image buffer A12. In this way, the contents of the two image buffers are alternately rewritten and displayed. The operation of the display is 60
At a repetition frequency of Hz to 72 Hz.

Also, to express dynamic movements,
In order to express a realistic feeling, the drawing / control unit 11 once draws in the image buffer A12, further processes the image and stores the combined result in the accumulation buffer 16. The upper part of the contents of the accumulation buffer 16 is transferred to the image buffer B13 and MP
The output of the image buffer B13 is supplied to the display unit 18 and displayed at X17.

When the drawing / control unit 11 draws in the image buffer A12, the drawing time may be several seconds to several tens of seconds depending on the image data. For example, when a curved surface is represented by ray tracing (ray tracing method).

However, once the image is drawn in the image buffer, the image can be processed within the repetition frequency of the operation of the display unit. Therefore, it is possible to realize an image in which an image drawn by ray tracing moves with an afterimage by synthesizing it on the accumulation buffer within the repetition frequency of the operation of the display unit.

In the three-dimensional graphics display device having the configuration described above, a double buffer configuration or an accumulation buffer is mounted to realize a high function, but when the accumulation buffer is used,
The upper 24 bits of the accumulation buffer will be used as the data to be displayed.

Therefore, in the example shown in the figure, the image drawn on the screen composed of the image buffer A12 and the Z buffer A14 is added to the accumulation buffer 16, and the higher 24 bits of the result are transferred to the image buffer B13 for display. .

If the coefficients used when processing the image drawn in the image buffer A12 are determined on the assumption that the upper 24 bits of the result are displayed, the upper 24 bits of the accumulation buffer 16 will be set. Digit alignment becomes unnecessary when transferring to the image buffer B13.

[0022]

As described above, in the conventional system, the dedicated accumulation buffer 16 is required in addition to the double buffer, and the image buffer B13 is used to display the result of the accumulation buffer 16.
Had to transfer to.

In view of the above points, the present invention has an object of providing a means for displaying a synthesized image as it is, having the functions of an accumulation buffer and an image buffer.

[0024]

The above-mentioned problems can be solved by a three-dimensional graphics display device constructed as follows.

FIG. 1 is a block diagram of the present invention. Corresponding to pixels to which color information and depth information are added, two sets of image buffers 12 and 13a that store the color information and two Z buffers 14 and 15a that store the depth information are provided to alternately draw and display. A three-dimensional graphics display device having a double buffer frame buffer 19a configured to connect an image buffer 13a on one side and a Z buffer 15a to form an accumulation buffer for storing a composite result of a plurality of images. .

[0026]

[Operation] Image buffer 13a and Z buffer 15a on one side
A memory having the number of bits required by the accumulation buffer is configured by connecting the. Therefore, this memory is used as an accumulation buffer.

Therefore, the conventional accumulation buffer becomes unnecessary. In addition, this image buffer 13a
When a memory in which the Z buffer 15a and the Z buffer 15a are connected to each other is used as an accumulation buffer, if the upper part of the accumulation buffer is associated with the image buffer 13a, the time for transferring from the accumulation buffer to the image buffer 13a becomes unnecessary.

[0028]

1 is a block diagram of a three-dimensional graphics display device according to an embodiment of the present invention. In the figure, 13a is an image buffer B, which is a memory for storing image information composed of 8 bits for each of RGB. Reference numeral 15a is a Z buffer B, which is a memory for storing depth information.

Image buffer B13a and Z buffer B15
It is also used as the accumulation buffer 16a in concatenation with a. In addition, the same reference numerals as those in FIG. 3 are the same.

When the image buffer B13a is also used as the upper 24 bits of the accumulation buffer 16a and the Z buffer B15a is also used as the lower 24 bits of the accumulation buffer 16a and the accumulation buffer 16a is used, the image buffer B13a and the Z buffer B15a are used. Are connected and used as the accumulation buffer 16a.

FIG. 2 is a block diagram of the accumulation buffer according to the embodiment of the present invention. In the figure, the drawing / control unit 11 sends the drawing data of 16 bits for each RGB, a total of 48 bits of data, and the upper 8 bits of RGB of the drawing data are transferred and stored in the image buffer B13a. It indicates that each 8 bits are stored in the Z buffer B15a.

When the figure drawn in the image buffer A12 is added to the image data in the accumulation buffer 16a to create a figure in which a plurality of images are combined and displayed, the upper two bits of the accumulation buffer 16a are displayed.
Since 4 bits are the image buffer B13a having a display function as it is, it is possible to display the image as it is without having to transfer it from the accumulation buffer to the image buffer by switching with the MPX17.

[0033]

As is apparent from the above description, according to the present invention, the accumulation buffer can be configured by using the image buffer on one side of the double buffer and the Z buffer, and the dedicated accumulation buffer is not required. Displaying can be performed without transferring to the image buffer, and there is a remarkable industrial effect that high-speed display can be performed during that time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a three-dimensional graphics display device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an accumulation buffer according to the embodiment of this invention.

FIG. 3 is an example of a configuration diagram of a conventional three-dimensional graphics display device.

[Explanation of symbols]

11 Drawing / Control Unit 12 Image Buffer A 13, 13a Image Buffer B 14 Z Buffer A 15, 15a Z Buffer B 16 Accumulation Buffer 17 MPX 18 Display Unit 19, 19a Frame Buffer

Claims (1)

[Claims] 1. An image buffer (12, 13a) for storing the color information and two Z buffers (14, 15a) for storing the depth information, each corresponding to a pixel to which color information and depth information are added. A three-dimensional graphics display device that has a frame buffer (19a) of a double buffer structure that holds and alternately draws and displays, and connects multiple image buffers (13a) and Z buffers (15a) on one side. A three-dimensional graphics display device characterized by comprising an accumulation buffer for storing an image synthesis result.