JPH01106284A - Three-dimensional image display control device - Google Patents

Abstract

PURPOSE:To rapidly display a three-dimensional model by storing the information of patterns on respective surfaces of the three-dimensional model independently of information relating to a light source. CONSTITUTION:A three-dimensional picture element display control device is constituted of a display processing part 3, a mapping processing part 4, a mapping buffer 5, a frame buffer 6, and a look-up table 8. The display processing part 3 inputs the three-dimensional model and the information of a light source or a color index corresponding to coordinates expressing the three-dimensional model, calculates the information of illumination on respective picture elements on the surfaces of the three-dimensional model or color coordinates and stores the calculated result in the frame buffer 6. The mapping processing part 4 outputs an image to which a mapping pattern is stuck to the mapping buffer 5. The look-up table 8 composes the contents of the frame buffer 6 with that of the mapping buffer 5 and displays the composed result on a CRT display 9.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Prior Art and Problems to be Solved by the Invention Means for Solving the Problems Action Examples Effects of the Invention [Summary] Expressed in dots It relates to a 3D image display control device that pastes and displays a mapping pattern on the surface of a 3D model, and in particular relates to mapping processing technology, including time-consuming mapping processing in 3D image display processing and changing light source information. The aim is to display 3D images at high speed by independently controlling the display processing associated with the 3D image, and to display the 3D image, information about the 3D model and the light source (9 types of light source positions, etc.), Alternatively, a display process that inputs a color index corresponding to the coordinates expressing the three-dimensional model, calculates illumination information (brightness and color index) at each pixel on the surface of the three-dimensional model, and stores it in a frame buffer. Under the control of the display processing section, the correspondence between each pixel on the surface of the three-dimensional model and the mapping pattern is calculated, and an image in which the mapping pattern is pasted onto the three-dimensional model is mapped. It is equipped with a mapping processing unit that outputs to a pin buffer, and a look-up table (LIT) that combines the contents of the frame buffer and the mapping buffer and displays it on a CRT display. ) is held independently from the information regarding the light source, and the segment buffer in which the display program is stored is stored based on the value of the mapping flag (MPF) set in the display program. Scan and extract the necessary display program,
The three-dimensional image is displayed by controlling the mapping buffer and the frame buffer independently.

[Industrial application field]

The present invention relates to a three-dimensional image display control device for pasting and displaying a mapping pattern expressed as dots on the surface of a three-dimensional model, and particularly relates to a mapping processing technique.

With recent advances in image processing technology, computer-aided design (
In fields such as CAD) and computer-aided manufacturing (CAM), it is now necessary to use image processing to display images of objects to be designed and manufactured from various viewpoints. Is it a two-dimensional display?
Or, in reality, it was displayed in a simulated three-dimensional form (wire frame).

Therefore, there is a problem that the finished shape cannot be clearly grasped, and a display that has texture and is close to the actual shape is required.
A display device capable of displaying a so-called solid model is now required.

In this case, it is essential to shorten the response time at each stage of the automatic design and manufacturing work, and as quickly as possible,
3 equipped with a display control means capable of displaying the solid model;
A dimensional image display controller is required.

[Prior art and problems to be solved by the invention] FIG. 5 is a diagram illustrating a conventional three-dimensional image display control system.

First, in the display processing unit 3', each image on each surface of the three-dimensional model is displayed based on the input three-dimensional model, mapping pattern, and light source information (one type of light source position, nine color indicators, etc.). The illumination information (brightness, one color, etc.) at the pixel is calculated, and the mapping processing unit 4' combines the information with the pattern on the surface of the three-dimensional model calculated and stores it in the frame buffer.

Among the above processes, details of the display process will be explained below.

FIG. 6 is a diagram explaining the concept of display processing, and (a)
indicates brightness calculation (shading) processing, (bl, b
2) shows surface painting processing.

Assuming that the viewpoint and the position of the light source for a certain surface (for example, surface 2) of a three-dimensional model composed of multiple surfaces are shown in Figure (a), the brightness 1i of each vertex on the tangent surface 2 is For example, it is expressed by the formula shown. Regarding the formula for calculating the brightness,
For example, (Chapter 16 of "Fundamentals of Interactive Computer Image Processing" by J. D. Foley, A. V. Dunn, Addison-Wesley Publishing Company, 1982 (J. D. Fole
y and^, V, Dan, “Fundamenta
ls of Interactive Con+put
er Graphics″+ @16+Addiso
n-Wesley Publishing Comp
any Inc., 19B2) Based on this formula, the brightness at each vertex can be calculated.

Next, the surface painting process on the contact surface 2 will be explained with reference to the (bl, b2) diagrams.

In the tangent surface painting process, the tangent surface 2 is expressed as the coordinates of each vertex indicated by the black dot in the figure (bl) (including the brightness 1. corresponding to each vertex obtained in the brightness calculation process described above) ((X++V+
+2++I+)+ (Xz+yz+Zz+Ig)+'-
”) are expressed as one set.

Generate a vector connecting each vertex from the vertex coordinates, and generate a vector string from each pixel on the vector in the vertical or horizontal direction as shown in the diagram (b2) (in this example, in the horizontal direction),
The end point coordinate data string is processed using a known digital differential analyzer (
output to ODA).

In the digital differential analyzer (ODA), a coordinate string connecting the end points of the vector is generated for each pixel. In addition to the three-dimensional coordinates (x, L z), this coordinate string also includes luminance values (
1) is included.

In the surface painting process, the coordinate values and brightness of each pixel on each surface of the three-dimensional model are determined at high speed by interpolation processing using digital differential analysis (DD^).

Next, mapping processing often used in three-dimensional image display will be explained.

FIG. 7 is a diagram showing the concept of mapping processing, and (
a) shows the 3D model ■, (b) shows the mapping pattern ■, (c) shows the correspondence between the 3D model ■ and the mapping pattern ■, and (d) shows the correspondence An example of the results is shown, (el, e2) shows the process of pasting the mapping pattern ■ corresponding to the brightness of each image on each side of the three-dimensional model ■ obtained in the above display process, and (f) shows the process of pasting the mapping pattern ■. It shows how to obtain the coordinates on the mapping pattern ■ from each coordinate of each surface of the dimensional model ■.

The mapping process is as follows: (a) =+(b) =+ in this figure.
As is clear from the processing process of (c) → (d) → (el, e2), the coordinate axes of the mapping pattern ■ (see figure (b)) are 1.2.
- Base vector 3 up vector ((C
)), the process performs coordinate transformation according to the figure), associates each surface with each other, and pastes the images.

Actually, as shown in figure (f), the coordinates (x+
y, z), coordinates (
Calculate the transformation matrix that rides X□yp), find the coordinates (xp+yr) on the mapping pattern ■, and
+Yp) is mapped to the luminance of each pixel on each surface of the three-dimensional model ((el)). )
The actual display information (brightness, one color, etc.) is synthesized with the following information.

The mapping process described above (see figure (f)), for example, is based on the International Organization for Standardization (ISO) standard r DP959.
2-1:1987(E), PHIGS 2nd DP,
An example of this is specified in "P-49 ~", so the details thereof will be omitted here.

As is clear from the above explanation, in the display processing, various (9 brightness colors, etc.) interpolation means (so-called
However, for mapping processing, the address of each pixel on the surface of the three-dimensional model ■ and the corresponding address of the mapping pattern ■ are calculated for each pixel (calculation of the transformation matrix). ), and in the conventional three-dimensional image display control system, as is clear from the configuration diagram in Figure 5, even when changing the position of the light source, nine types of directions (point light source, parallel light), etc. , the above-mentioned display processing, and mapping processing, there is a problem in that it is difficult to speed up the display.

In view of the above conventional drawbacks, the present invention provides a three-dimensional image that can increase the display speed in three-dimensional image display in which a mapping pattern of a two-dimensional image displayed as dots is pasted onto the surface of a three-dimensional model. The object of the present invention is to provide a display control device.

[Means for solving problems]

FIG. 1 is a diagram showing the principle of a three-dimensional image display control device according to the present invention. The above problems are solved by a three-dimensional image display control device having the following configuration.

(1) A three-dimensional image display control device that displays a mapping pattern expressed as dots pasted on the surface of a three-dimensional model, which has one type of light source position with respect to the three-dimensional model.

Alternatively, based on the color index, illumination information for each pixel on each surface (luminance value, one color index, etc.), or the three-dimensional coordinates expressing the three-dimensional model, and the color index corresponding to each coordinate, A display processing unit 3 that calculates color indices for surface pixels, and a three-dimensional address (X, Y
, Z), if the Z address value is equal to the contents of the two-dimensional address (X, Y) of the Z buffer 34, the address (XP') of the mapping pattern corresponding to that address (X, Y) is , YP)
and writes and holds the contents of the address (Xp, Yp) of the mapping pattern corresponding to each pixel (X, Y) of the graphic element forming the three-dimensional model, calculated by the mapping processing unit 4. a mapping buffer 5; a frame buffer 6 for storing the luminance value or color index for each pixel (X, Y) constituting the graphic element forming the three-dimensional model output from the display processing unit 3; Either the contents of the mapping buffer 5 are combined, or the volatility value or color index of each pixel (X, Y) constituting the graphic element forming the three-dimensional model output from the display processing section 3 is combined. , and a look-up table (LUT) 8 for synthesizing the contents of the mapping buffer 6.

(2) In the three-dimensional image display control device, the display program stored in the segment buffer 11 is scanned, and the mapping flag (MPF) in the display program is scanned.
) is "off", the data is written to the frame buffer 6, and when the mapping flag (MPF) is "on", data is written to the mapping buffer 5 based on the display program taken out. and a segment management unit 1 that performs writing, and the segment management unit 1 updates the display program in the segment buffer 11 with the mapping flag (
MPF), the mapping process for writing to the mapping buffer 5 and the display process for writing to the frame buffer 6 are independently controlled to display a three-dimensional image. Configure.

[Effect]

That is, according to the present invention, it is composed of a display processing section, a mapping processing section, a frame buffer, a mapping buffer, and a lookup table (LUT),
The display control unit inputs information on the 3D model and light source (9 types of positions, etc.) or a color index corresponding to the coordinates expressing the 3D model, and displays information on illumination at each pixel on the surface of the 3D model. , or calculate the color index and set the frame,
Store in buffer.

The mapping processing section performs three operations under the control of the display processing section.
The correspondence between each pixel on the surface of the dimensional model and the mapping pattern is calculated using a transformation matrix, and an image in which the mapping pattern is pasted onto the three-dimensional model is output to a mapping buffer.

Then, the lookup table (LUT) combines the contents of the frame buffer and mapping buffer and outputs the CRT.
It functions to display on the display.

With this configuration, information about the pattern on each surface of the three-dimensional model (i.e., mapping pattern) can be held independently of information about the light source (brightness or color index), so the information about the light source When changing one type of position or direction, you only need to perform display processing and synthesize using a lookup table (LUT).
This has the effect of enabling high-speed display of three-dimensional models.

〔Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

The above-mentioned FIG. 1 is a principle diagram of the three-dimensional image display control device of the present invention, in which (a) shows the case where the contents of the frame buffer and the mapping buffer are combined and displayed, and (b) shows the display processing unit. This shows a case where the luminance generated in 1 and the contents of the mapping buffer are combined and stored in a frame buffer and displayed. FIG. 2 is a block diagram showing an embodiment of the present invention. FIG. 3 is a diagram explaining the management operation of the segment management section of the present invention, in which (a) shows an example of a graphic display program, (b) shows an example of scanning for the graphic display program, and FIG. The figure shows an example of coordinate transformation processing, and shows the display processing unit 3. Mapping processing section 5° segment management section 1. and a look-up table (LUT) 8 are the necessary means to implement the invention. Note that the same reference numerals indicate the same objects throughout the figures.

Hereinafter, the three-dimensional image display control device of the present invention will be explained with reference to FIGS. 2 to 4 while referring to FIG.

First, in FIG. 2, in the segment buffer 11,
A three-dimensional model, light source information (position 1 intensity, etc.), mapping pattern, mapping flag (MPP), etc. are stored as a graphic display program.

FIG. 3(a) shows an example of the graphic display program described above, where ■ indicates an example of a three-dimensional model to be displayed;
(2) shows an example of a mapping pattern, and (2) is an example of a program that displays the three-dimensional model (2) using the mapping pattern (2).

In this graphic display program (■), MPF ON: This is a command to turn on the mapping flag (MPF).

5ET-R3 (10,0,0), Po, 10,1: A command specifying light source information, where (10,0,0) indicates the position of the light source.

S E T-M P (16,16), (0,1,0
,1,-・,0,1.0): For example, 16 pixels x 16
(0,1°0,L-,0,1,0) is a command to register the mapping pattern shown in (■) consisting of pixels in a memory area (not shown) of the mapping processing unit 4. (0,1°0,L-,0,1,0) It shows.

MDL l: This is a command to specify the name of the three-dimensional model indicated by ■, and the command written next (SET
-MP-REF, PLG3. etc.) specifies display conditions for the three-dimensional model (2).

SET-MP-REF (0,6,2), (2,3,1)
, (0, 3, 2), . . .: For example, these are commands that specify the up vector and base vector, which are the mapping reference points for surface 1 of the three-dimensional model (3).

P L G 3 (0,0,2), (0,6,2), (
4,6,0), (4,0,0), -------: Graphic display command (or order) for surface 1 of the 3D model of ■ to display based on the above mapping conditions. is instructing.

Similar display programs will be described below for each side 2, 3, and 4.5.

The segment management unit 1 in FIG.
management and overall control of the display device.

That is, when displaying the three-dimensional model ■, the segment management unit 1 first turns off the mapping flag (MPF) and sequentially scans the graphic display program ■ in the segment buffer II (referred to as the first scan). ), extracts the command group ■ excluding commands related to mapping processing (for example, SET-MP, etc.), and executes the coordinate transformation/clipping unit 2.
Output to.

(See Figure 3(b)) Next, turn on the mapping flag (MPP),
The graphic display program (2) is scanned again (referred to as a second scan), and the command group (2), excluding the command group for instructing the position of the light source, etc., is output to the coordinate conversion/clipping section 2. (Refer to FIG. 3(b)) By executing the output command groups ■ and ■, display processing including, for example, writing processing to the frame buffer 6 and writing processing to the mapping buffer 5 is executed, respectively. Ru.

The coordinate transformation/clipping section 2 performs known matrix operations on the input coordinate values of the three-dimensional model (■) using a transformation matrix (current matrix) as shown in FIG. rotation, movement,
Geometric transformations such as enlargement and reduction are performed to generate output coordinate values. At this time, if the output coordinate value protrudes outside the display area, so-called clipping is performed.

Furthermore, using the graphic display program ■ or ■ above,
If a change in the current matrix required for the coordinate transformation is instructed, the changed transformation matrices are sequentially output.

In the next brightness calculation unit 31, when the mapping flag (MPF) is “off”, that is, when displaying without performing mapping processing, the brightness calculation process necessary for display processing is performed by the coordinate transformation/clipping unit 31. Coordinate values of each vertex of the 3D model ■ input from.

The normalized reflected light intensity and color at each vertex based on the normal vector, the normal reflectance (diffuse reflectance, specular reflectance) on each surface, and light source information (position, brightness, etc.) The information (If) (see Figure 6) is searched by a color index (not shown) for searching a display color table (not shown).
The current matrix (transformation matrix) generated by the coordinate transformation/clipping section 2 described above is not related to the brightness calculation process, so it is output as a color index: Ii), and is then outputted to the next surface painting section 32. Output to.

However, if the mapping flag (MPF) is "on", the brightness calculation process is not performed as described above.
All the information generated by the above-mentioned transformation/clipping section 2, etc., such as the output coordinate values of the three-dimensional model (■), the current matrix, the up vector, the base vector, etc., are transferred to the luminance calculation section 31 without doing anything. Side, surface painting part 32
Send to.

In the surface painting section 32, a vector sequence (see 6th tl (b2)) that internalizes the three-dimensional model (2) is generated, and further,
When the mapping flag (MPF) is "off", only the brightness calculation is required, so the color index (It', It''') at the end point of each vector sequence is
is calculated at high speed by interpolation in the DDA unit 33, which will be described later, using the color index (■) of each vertex. (See FIG. 6 (b2)) The next DDA section 33 inputs the vector string generated by the surface painting section 32 and generates a coordinate string connecting the end points of each vector string for each pixel, Furthermore, if the mapping flag (MPP) is "off", the color index (If"+Ii") at the end point of each vector is
) to quickly generate a color index at each pixel.

In the Z buffer 34, the coordinate value (X+LZ) output from the DDA section 33 is input, and the Z buffer 3
If the content (Z value) of the coordinates (x, y) on 4 is smaller than the newly input Z value, that is, if the tangent surface is recognized to be on the surface, the coordinates (x, y) y) to a new Z value, and at the same time update the color index (Ii ) is sent to the frame buffer 6.

Therefore, in the frame buffer 6, the mapping flag (MPF) is "off" and the write permission signal (WFB) from the Z buffer 34 is
The corresponding coordinates (x, y
) (color index two-color index (It)) is updated.

In addition, in the mapping processing section 4, only when the mapping flag (MPF) is "on", the mapping processing section 4 processes the DDA
Input the coordinate values (x+y+z) output from 32,
The Z value of the corresponding coordinate is the corresponding coordinate (x
, y), that is, only when it is recognized as the surface that is the closest to the surface, its coordinate value (x+y+z
) of the mapping pattern coordinate value (Xp+)'r
) is calculated (see FIG. 7(f)), and its contents (dot data of the mapping pattern) are inserted into the corresponding coordinate values (x, y) on the mapping buffer 5.

In the embodiment shown in FIG. 2, a lookup table (LIT) 8 combines the contents of the mapping buffer 5 and the frame buffer 6, and outputs the result to the CRT display 9 for display. (Corresponding to Figure 1 (a)) Specifically, a lookup table is created using the values of the mapping buffer 5 and the frame buffer for each pixel corresponding to the new coordinates of the 3D model that have been transformed. Searched and read brightness.

The pixel will be displayed based on color.

In the above example, it is possible to quickly switch whether or not to perform mapping display based on the contents of the mapping buffer 5 and frame buffer 6 that have been previously written.

In the configuration example shown in FIG. 1(b), the display processing unit 3
The result data (force index: ■,) and the result data of the mapping buffer 6 that has been generated in advance are synthesized using a lookup table (LtlT) 8 and written to the frame buffer 5. 5
Therefore, if the position or type of the light source is changed, it will take extra time to write to the frame buffer 6 compared to the case shown in Fig. 1(a).
As in example a), it is possible to omit the mapping process,
This does not impede the gist of the present invention.

In either case, by implementing the present invention, information on the surface pattern (mapping pattern) of the three-dimensional model (mapping buffer) is controlled to be held independently from information on the light source (frame buffer). Therefore, when changing the position or type of the light source, time-consuming mapping processing for address calculation can be omitted, and the three-dimensional model can be displayed at high speed.

〔Effect of the invention〕

As described above in detail, the three-dimensional image display device of the present invention displays the three-dimensional image using the three-dimensional model and information on the light source (one type of light source position, etc.), or the three-dimensional model. a display processing unit that inputs a color index corresponding to the coordinates representing the three-dimensional model, calculates illumination information (brightness and color index) at each pixel on the surface of the three-dimensional model, and stores it in a frame buffer; Under the control of the processing unit, the correspondence between each pixel on the surface of the three-dimensional model and the mapping pattern is calculated, and an image in which the mapping pattern is pasted onto the three-dimensional model is output to the mapping buffer. A mapping processing unit and a look-up table (LUT) that combines the contents of the frame buffer and the mapping buffer and displays the result on a CRT display are provided, and information on the surface pattern (mapping pattern) of the three-dimensional model is provided. The segment buffer in which the display program is stored is stored independently of the information regarding the light source, and the mapping flag (M
PF), extracts the necessary display program, and independently controls the mapping buffer and frame buffer to display the three-dimensional image, so the position of the light source, When changing the nine types of directions, etc., only display processing is required, which has the effect of enabling high-speed display of the three-dimensional model.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of a three-dimensional image display control device according to the present invention. FIG. 2 is a block diagram showing an embodiment of the present invention. FIG. 3 is a diagram explaining the management operation of the segment management section of the present invention. FIG. 4 is a diagram showing an example of coordinate transformation processing. FIG. 5 illustrates a conventional three-dimensional image display method, and FIG. 6 illustrates the concept of display processing. FIG. 7 is a diagram showing the concept of mapping processing. It is. In the drawing, 1 is the segment management department. 2 is the coordinate transformation/clip part. 3.3' is a display processing section, and 31 is a brightness calculation section. 32 is the surface painting part, and 33 is the DDA part. 34 is Z buffer. 4.4' is the mapping processing section. 5 is a mapping buffer. 6.6 is the frame buffer. 8 is a lookup table (LIT). 9 is a CRT display. ■ is a 3D model. ■ is a matsuping pattern. ■～■ are graphic display programs. are shown respectively. wo flame 7L seven del/2 throat greeting wo Ming Q death shoes. : (cL) ;bi RiqshiQ 1shiJ Sumami Natsushikugu/F ヲfig.A'4,ノε 493.S',n FL L17
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Claims (2)

[Claims] (1) A three-dimensional image display control device that displays a dot-expressed mapping pattern pasted on the surface of a three-dimensional model, which A display that calculates a color index for the surface pixel based on illumination information (brightness value, color index, etc.) for each pixel above, or three-dimensional coordinates expressing the three-dimensional model, and a color index corresponding to each coordinate. Processing section (3
) and a three-dimensional address (X
, Y, Z), the Z address value is stored in the Z buffer (
a mapping processing unit (4) that calculates an address (X_P, Y_P) of a mapping pattern corresponding to the address (X, Y) when the content is equal to the two-dimensional address (X, Y) of 34); A mapping buffer (5) that writes and holds the contents of the address (X_P, Y_P) of the mapping pattern corresponding to each pixel (X, Y) of the graphic element forming the three-dimensional model, calculated by the processing unit (4). ), a frame buffer (6) that stores the brightness value or color index for each pixel (X, Y) constituting the graphic element forming the three-dimensional model output from the display processing unit (3);
The contents of the mapping buffer (5) are synthesized, or the brightness value of each pixel (X, Y) constituting the graphic element forming the three-dimensional model output from the display processing unit (3), or color index and the above mapping buffer (6
) to synthesize the contents of the lookup table (LUT) (
8) A three-dimensional image display control device comprising: (2) In the three-dimensional image display control device, the display program stored in the segment buffer (11) is scanned, and the mapping flag (M
Based on the display program taken out when the mapping flag (MPF) is 'off', writing is performed to the frame buffer (6) described in item 1 above, and the mapping flag (MPF) is
a segment management unit (1) that writes to the mapping buffer (5) described in the above item 1 based on the display program retrieved when the segment management unit (1) is 'on'; The display program in the segment buffer (11) is set to the above mapping flag (
By selectively scanning based on MPF), the mapping process that writes to the mapping buffer (5) and the display process that writes to the frame buffer (6) are independently controlled to create a three-dimensional image. The three-dimensional image display control device according to claim 1, wherein the three-dimensional image display control device displays: