JPS63298489A - Hidden face processing device - Google Patents

Abstract

PURPOSE:To perform the hidden face processing of a semitransparent object by providing a transparency control part. CONSTITUTION:A hidden face processing part and a transparency control part 1 are provided. The transparency of a segment and segment information to be inputted to the hidden face processing part 2 are inputted to the control part 1, and the control part 1 holds a painting-out pattern in XY directions selected by the inputted transparency of the segment and validates inputted segment information by the transparency, the current scan line position, and respective M values of hidden face processors 2-1' and 2-2' and outputs it to N-number of hidden face processors 2-1' and 2-2'. That is, since segment information inputted to N-number of hidden face processors 2-1' and 2-2' is validated or invalidated by the transparency control part 1 in accordance with the transparency of the segment, the current scan line position, and M values, the hidden face processing of the semitransparent object is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hidden surface processing device in a three-dimensional converter graphics device that projects and displays a three-dimensional polyhedral object on a two-dimensional screen.

Conventional technology When displaying a composite of three-dimensional objects on a two-dimensional screen, it is necessary to somehow deal with the phenomenon in which objects in the foreground partially or completely hide objects in the background. No. Generally, the scan line method, which processes sequentially using a general-purpose processor, and the two-buffer method, which is suitable for hardware implementation, are known.

As an intermediate method of hidden surface processing between these two methods, there is a method that uses correlation between scan lines and a two-buffer method within one scan line.
Super Buffer Assistric Buoy El Nis Eye Graphic Engine for Real Time Raster I)-Sichéneration”, 1985
Although it is shown in Chapel Hill Conference on Large Scale Integration, 7, PP285-305, the hardware is too large and it is difficult to incorporate the entire array into an LSI. Therefore, we applied for a patent application in 1988 as a device suitable for LSI implementation with a small amount of hardware.
We proposed a hidden surface processing device as shown in the specification of No. 0-241063, and further connected the hidden surface processing devices in parallel to increase the number of horizontal display pixels and speed up the processing speed. A hidden surface processing device as shown in Japanese Patent No. 92752 has been proposed.

FIG. 4 is a system block diagram of the proposed hidden surface processing device, and FIG. 6 is a hidden surface processing device that is a component thereof. In FIGS. 4 and 5, 2-1 and 2-2 are hidden surface processors that input segment data, perform hidden surface processing, and output brightness data; 41 is a hidden surface processor that inputs segment data and outputs luminance data; -i + M) A segment division converter that extracts only the segment data of the pixel, converts it into pseudo segment data compressed by 1/N times in the scan line direction, and outputs it; 42 performs hidden surface processing for each pixel; The operation of the hidden surface processing device configured as 0 or more, which is a pixel arithmetic unit that outputs the result to the IBUS, will be explained with reference to the conceptual diagram shown in FIG.

Polygon 61 defined in three-dimensional space as shown in Figure 6
is projected onto the XY plane and displayed on the screen. In a rask scan type CRT, etc., this process is performed for each horizontal scan line. Therefore, processing is performed on the XZ screen cut at the current scan line. Segment 62 which is the cut of polygon 51 at the current scan line
is expressed by left end point coordinates (X, Z), segment length dX, Z coordinate displacement per unit pixel dZ/dX, and brightness data. Segment tokens having this information are input to the hidden surface processor 2-1.2-2 to perform hidden surface processing.

First, when the segment tokens shown in FIG. -1, each pixel arithmetic unit 42 performs hidden surface processing on odd-numbered pixels in each pixel arithmetic unit 42 of the hidden surface processor 2-2. Hidden surface processing within one pixel arithmetic unit is performed as follows.

To checks whether it is within the valid range of the segment, T1 updates the depth coordinate Z only when it is within the valid range, and T2 updates the Z buffer value in the pixel calculator and the token 2 only when it is within the valid range. Compare the values and 2 of the tokens
If the value of is not larger, rewrite the contents of the Z buffer and E buffer to the value in the token. In this way,
A plurality of segment data within one scan line are sequentially processed in the form of segment tokens by a hidden surface processor 2. -1.2-2
, the hidden surface processing results for even-numbered pixels are sent to the buffers of each pixel arithmetic unit 42 in the hidden-surface processor 2-1, and the hidden-surface processing results for odd-numbered pixels are sent to each pixel calculation unit 42 in the hidden surface processor 2-2. It is held in the epuffer of the pixel arithmetic unit 42.

Next, when the hidden surface processing for one scan line is completed, the sweep token shown in FIG.
2, the brightness data of even-numbered pixels is input from the I buffer of each pixel calculation unit 42 in the hidden surface processor 2-1, and the brightness data of odd-numbered pixels is input to each pixel calculation unit in the hidden surface processor 2-2. The signals are output from the buffers of the device 42 in sequence. Processing within one pixel arithmetic unit is performed as follows. TO checks whether the pixel is within the CRT scanning line,
T1 outputs the e-buffer value to IBUS, T2 outputs 2
Initialize the buffer and I buffer.

Perform the above process for one screen worth of scan lines,
If the process is repeated further, a three-dimensional polyhedral object can be displayed on a two-dimensional CRT screen in real time.

Problems to be Solved by the Invention However, the above configuration has a problem in that it is impossible to display translucent objects because objects in the foreground completely hide objects in the background.

In view of this, an object of the present invention is to provide a hidden surface processing device that can also display semitransparent objects.

Means for Solving the Problems The present invention provides segment information (
N-i+M) Hidden surface processing unit that performs only pixel-th hidden surface processing and outputs luminance data. N hidden surface processors are connected in parallel, and the value of M of each hidden surface processor is set from 1 to NIC. Then, input the transparency of the segment and the segment information to be input to the hidden surface processing section, hold the filling pattern in the X and Y directions selected according to the input transparency of the segment, and calculate the transparency, current scan line position, ゛ and the hidden The hidden surface processing device includes a transparency control unit that validates the input segment information and outputs it to each of the N hidden surface processing devices according to the value of M of each of the surface processing devices.

According to the present invention, with the above-described configuration, the transparency control unit can enable or disable the segment information input to each of the N hidden surface processors according to the transparency of the segment, the current scan line position, and the value of M. Hidden surface processing for semi-transparent objects can also be performed.

Embodiment FIG. 1 is a system block diagram of a hidden surface processing apparatus in an embodiment of the present invention when N=2.

In Figure 1, 1 inputs the segment transparency T and segment data DI, and sets the segment data to valid or Fi.
Transparency control section that disables and outputs divided into two systems, 2
In this example, two hidden surface processors 2-1 for performing hidden surface processing on odd-numbered pixels and 2-2 for performing hidden-surface processing on even-numbered pixels as shown in the conventional example are connected in parallel. This is a hidden surface processing unit that inputs segment data and outputs brightness data as a result of hidden surface processing.

The operation of the hidden surface processing apparatus of this embodiment configured as described above will be explained using the diagram of FIG.

When the transparency of a polygon is represented by 2 bits, and a black circle means solid color and an x means transparent, a solid color (turn) as shown in Figure 3 is created.In other words, it has 2 bits as transparency. When the current polygon data hides the polygon in the back, if a transparency = oo (0%), hidden surface processing is performed for all pixels, and if b transparency = 01 (60%), 2 pixels are hidden. Perform hidden surface processing on one pixel among them, and if C transparency = 10 (75%), perform hidden surface processing on one pixel among the four pixels, and if d transparency = 11 (100%). For example, hidden surface processing will not be applied to any pixel.The fill pattern in the X and Y directions is determined by the transparency of the polygon, so once the transparency and XY coordinates are determined, it is necessary to decide whether to perform hidden surface processing on that pixel. can be determined.

In a system in which segment data is input in units of scan lines, as in the case of this embodiment shown in FIG. XY with segment transparency
When a fill turn in the direction is selected, the presence or absence of fill is determined by updating the Y direction between scan lines and separating the X direction between hidden surface processors, and performs hidden surface processing for translucent objects. Can be done. That is, fill patterns a to d are selected depending on the transparency of the input segment, Yo or Y'1 is selected depending on whether the current scan line is odd or even, and Xo or Xl is selected depending on the value of M of the hidden surface processor. Therefore, the presence or absence of hidden surface processing is determined. If the selected pattern is a black circle, the input segment is enabled, and if the selected pattern is X, the input segment is disabled, and the transparency control unit 1 If the output is output to the hidden surface processing unit 2 having each hidden surface processing unit 2-1 and 2-2, the hidden surface processing unit 2 processes the hidden surface according to the selected fill pattern, and uses the sweep token as the hidden surface processing result. luminance data is output. In addition, in the transparency control section, when enabling segment data, the input segment data is output as is, and when disabling segment data, instead of the input segment data, the left end point coordinate of the segment or a value larger than the number of horizontal pixels is output. It is sufficient to output dummy data, which is segment data that does not become active.

FIG. 2 is a block diagram of a transparency control section which is a component of the hidden surface processing apparatus of this embodiment shown in FIG.

In FIG. 2, 11 is a decoder that inputs, decodes and outputs the segment transparency T, and 12 is A for detecting a sweep token and transmitting scan line update.
ND gate 13 updates the scan line and indicates whether it is an odd line or an even line, a 1-bit counter 21
~24 and 31~34 are registers that hold transparent fill patterns, and 25 and 36 are scan line 4 registers.
The above registers 21 to 24 and 31 depending on the odd number or even number of
Selector for selecting a filling pattern from ~34, 2
6 and 36 are AND gates that output the presence or absence of filling in each segment, and 27 and 37 are selectors that select and output either segment data or dummy data depending on the presence or absence of filling. Note that 21 to 27 are for outputting segment data to the hidden surface processor for odd-numbered pixels in the scan line, and 31 to 37 are for outputting segment data to the hidden surface processor for even-numbered pixels. belongs to.

The operation of the transparency control unit in the hidden surface processing apparatus of this embodiment configured as described above will be described below.

It is assumed that the registers 21-24 and 31-34 already contain the filling pattern shown in FIG. That is, pattern a is in register 21.31, pattern b is in register 22.32, and pattern b is in register 23.33.
contains the C pattern, and the d pattern in registers 24 and 34. More specifically, the XO pattern is stored in registers 21 to 24, and the xl pattern is stored in registers 31 to 24.
34, and the YO pattern is in registers 21-24°3.
It is assumed that the Yl pattern is on the A side of Nos. 1 to 34 and on the B side.

When the sweep token shown in FIG. 7 is input, a signal indicating whether the current scan line is an odd number or an even number is output from the counter 13 to which the scan line update signal is input via the gate 12. Then, when the transparency T of one segment in the current scan line is input to the decoder 11,
One register each of registers 21-24 and 31-34 is selected, and a fill pattern is output from the selected register. The outputted fill-in pattern is selected by selectors 25 and 35 to be either the A side of odd lines or the B side of even lines and is output.

The fill-in presence/absence signals output from the selectors 25 and 36 are input to the selectors 27 and 37 during the timing of To-T3 via the gates 26 and 36, and when the fill pattern is a black circle, the fill-in presence/absence signals are input to the selectors 27 and 37 through the gates 26 and 36.
When the A side of 7 is the crushing pattern X, the B side of the selectors 27 and 37 is selected and output. That is, when the filling pattern is a black circle, the segment talk shown in Figure 7a is Ai = "FFFF" (x
= 'FFFF') are output to the hidden surface processors of odd-numbered pixels and even-numbered pixels, respectively.

As described above, according to this embodiment, by providing the transparency control section, hidden surface processing of a translucent object can be performed. Furthermore, even if the segment data to be input to the hidden surface processing device is not complete, the system configuration is such that it can be handled by inputting transparency=11 (100%).

As described in detail, according to the present invention, hidden surface processing of translucent objects can be performed, and its practical effects are great.

[Brief explanation of the drawing]

Brief explanation of inspection drawings: Figure 1 is a system block diagram of a hidden surface processing device according to an embodiment of the present invention, Figure 2 is a block diagram of a transparency control section in the hidden surface processing device of the same embodiment, and Figure 3 4 is a system block diagram of a conventional hidden surface processing device. FIG. 5 is a block diagram of a hidden surface processing device used in the embodiment of the present invention and the conventional example.
The figure is an explanatory diagram of a concept shared by the hidden surface processing apparatus of the present invention and the conventional hidden surface processing apparatus, and FIG. 7 is an explanatory diagram of the input of the hidden surface processing apparatus of the embodiment of the present invention and the conventional example. 1...Transparency control section, 2...Hidden surface processing section. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 ((1) Transmission return-65 (r3%) 0 × o × × 0 × 0 (b) tvx宸-a/ (50%) OX O × × × × × (C) tlJ degree -/a (75'h) xxx ×××× Cdl construction!! leak @17 (100"/,)Figure 4's 0 Figure 6 Figure 7 (cL) Segu"Nunto Token (b) Swivetogun

Claims (1)

[Claims] A plurality of segment information is input sequentially in units of one scan line on the screen, and among the input segment information (
N・i+M) [i: Integer satisfying O≦i, variable; N: N
=2^n, integer satisfying 1≦n, fixed, configurable; M:
Integer that satisfies 1≦M≦N, fixed, configurable] N hidden surface processors that perform only hidden surface processing for the pixel and output brightness data are connected in parallel, and M of each hidden surface processor is set as a value. 1~
Input the hidden surface processing section set to N, the transparency of the segment, and the segment information that should be input to the hidden surface processing section,
The filling pattern in the XY directions selected according to the transparency of the input segment is held, and the input segment information is enabled or disabled depending on the transparency, current scan line position, and the value of M of each of the hidden surface processors, and the N What is claimed is: 1. A hidden surface processing device comprising: a transparency control section that outputs an output to each of the hidden surface processing devices.