JP3553249B2 - Image generating apparatus and image generating method - Google Patents

Description

[0001]
【table of contents】
The present invention will be described in the following order.
Technical field to which the invention pertains Conventional technology (FIGS. 9 to 12)
Problems to be solved by the invention (FIG. 13)
Means for Solving the Problems Embodiments of the Invention (1) Configuration of Image Generation Device (FIGS. 1 to 5)
(2-1) When texture mapping is performed on a three-dimensional polygon (Fig. 6)
(2─2) Fon shading on a three-dimensional polygon (Fig. 7)
(2─3) When texture mapping is performed on three-dimensional polygons and further fountaining is performed (Fig. 8)
BACKGROUND OF THE INVENTION
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image generation apparatus and an image generation method, and particularly to an image memory such as a game machine or a computer, in which an image generated by calculation or an image read from a storage device is drawn on the image memory, and is displayed on a display. It is suitable to be applied to those which output to
[0003]
[Prior art]
Conventionally, in an image generating apparatus which draws image data on an image memory and reads and displays the image data in accordance with a synchronization signal of a television, the pixel values to be displayed are arranged in the image memory, and the reading apparatus simply stores them. Most of them are read out according to a video synchronizing signal, D / A (digital / analog) converted and displayed on a display.
[0004]
Here, FIG. 9 shows a configuration example of a conventional image generation device. The image generation device 1 includes a CPU 2, a main memory 3, an image generation processor 4, an image memory 5, and an image output processor 6, and the CPU 2, the main memory 3, and the image generation processor 4 are connected to a main bus 7, respectively. It can send and receive data. The image generation processor 4 and the image memory 5 are connected so that data can be exchanged. The output signal from the image memory 5 is connected via an image output processor 6 to a monitor or the like. The main memory 3 stores a program for generating an image.
[0005]
First, a case in which texture mapping is performed on a three-dimensional polygon in the conventional image generation device 1 will be described. A polygon is a minimum unit (a triangle or a quadrangle) of a figure handled by the drawing apparatus.
The CPU 2 outputs a drawing command to the image generation processor 4 according to a program stored in the main memory 3, and the image generation processor 4 reads a texture image from the image memory 5 according to the drawing command. After the texture image read from the image memory 5 is modified, the texture image is written into the display area in the image memory 5 again. The image output processor 6 reads out the display area in the image memory 5 according to the video synchronization signal and outputs it.
[0006]
FIG. 10 shows the contents of the memory area 10 in the image memory 5 when the texture mapping is performed on the three-dimensional polygon described above. The memory area 10 is formed by a display area 11 in which an image to be displayed is generated and a texture area 12 in which a texture image is stored. A plurality of polygon areas are calculated in the display area 11, and the corresponding texture pixels are read, transformed and written.
[0007]
For example, in order to texture-map the triangle PQR of the texture 12a to the triangle ABC, the pixel value of the point S in the triangle PQR corresponding to each point E included in the triangle ABC is copied. All of these processes are performed by the image generation processor 4, and are written to the display area 11 of the image memory 5 after completion.
[0008]
Next, a case in which three-dimensional polygons are subjected to founseeing in the conventional image generation device 1 will be described.
The CPU 2 outputs a drawing command to the image generation processor 4 according to the program, and the image generation processor 4 calculates the coordinates of the vertices of the polygon and the values of the pixels included therein according to the command, and the display area 11 in the image memory 5. Write to. The image output processor 6 reads and outputs the display area 11 in the image memory 5 according to the video synchronization signal.
[0009]
FIGS. 11A and 11B show the contents of the memory area 10 in the image memory 5 when the above-described three-dimensional polygon is subjected to financing.
All the processing described below is performed by the image generation processor 4. In the display area 11 in the memory area 10, a plurality of polygon areas are calculated, and the values of the pixels included therein are calculated and written. For example, in order to conduct a triangle ABC on a triangle, a normal on a point E in the triangle is obtained from normals on three vertices A, B, and C, and a dot product of the normal and the light source vector is obtained. The pixel value at that point is used. After this processing, the data is written to the display area 11 of the image memory 5.
[0010]
Further, a case in which texture mapping is performed on a three-dimensional polygon in the conventional image generating apparatus 1 and further founshading is performed will be described.
The CPU 2 outputs a drawing command to the image generation processor 4 according to the program, and the image generation processor 4 reads the texture image from the image memory 5 according to the command, modifies the texture image, performs shading, and again performs display in the image memory 5. Write to area 11. The image output processor 6 reads out and outputs the display area 11 in the image memory 5 according to the video synchronization signal.
[0011]
FIGS. 12A and 12B show the contents of the memory area 10 in the image memory 5 when texture mapping is performed on the above-described three-dimensional polygon, and thereafter, font shading is performed. I have. The following processes are all performed by the image generation processor 4.
In the display area 11 in the memory area 10, a plurality of polygon areas are calculated, the corresponding texture images are read, transformed, shaded, and written.
[0012]
For example, in order to texture map the triangle PQR of the texture 12a to the triangle ABC, the pixel value of the point S in the triangle PQR corresponding to each point E included in the triangle ABC is copied. Further, the normal on the point E in the triangle is obtained from the normals on the three vertices A, B, and C, the inner product of the normal and the light source vector is obtained, and the result is multiplied by the texture value of the point to obtain a pixel value. . Thereafter, the data is written to the display area 11 of the image memory 5.
[0013]
[Problems to be solved by the invention]
However, in the above-described configuration, the image generation processor 4 once reads out pixel data from the memory area 10 (texture area 12) of the image memory 5 in which the image data is stored, performs processing, and then writes the pixel data into the image memory 5. There is a need. That is, in order to process one pixel, there is a disadvantage that reading from the image memory 5 and writing to the image memory 5 are required at least once each.
[0014]
In image generation, a technique called "hidden surface removal" is used to realistically represent a three-dimensional object. For example, in an image in which the hidden surface is erased by overwriting as shown in FIG. 13, more polygons are actually written in the memory than the polygons displayed on the screen. Due to the hidden surface erasure, the image data once drawn on the memory area 10 of the image memory 5 may be overwritten and erased. However, there is a problem that the processing of the image data erased by the overwriting is wasted.
[0015]
The present invention has been made in consideration of the above points, and has as its object to realize an image generating apparatus and an image generating method capable of reducing unnecessary data processing.
[0016]
[Means for Solving the Problems]
An image generation apparatus according to the present invention corresponding to the above-described object includes an image memory, an image generation processor that writes data corresponding to each pixel and a pixel mode representing the meaning of the data in a display area of the image memory, An image output processor that reads the stored data and the pixel mode, determines a pixel mode of the read data, and performs a predetermined process corresponding to the determined pixel mode to create an output image. The apparatus , wherein the pixel modes include first, second, third, and fourth pixel modes, wherein in the first pixel mode, the image generation processor writes RGB values to the display area, the output processor creates an output image based on the RGB value, and in the second pixel mode, the image generation flop The processor writes a texture address in the display area, the image output processor reads texture data from the image memory based on the texture address to create an output image, and in the third pixel mode, the image generation processor In the display area, while writing data of a normal vector of a vertex of a polygon, the image output processor creates an output image based on an inner product value of the normal vector and the light source vector, and in the fourth pixel mode, The image generation processor writes a texture address and data of a normal vector of a vertex of a polygon to the display area, and the image output processor reads texture data from the image memory based on the texture address. Calculates the inner product value between the normal vector and the light source vector, to create the output image based on the integrated value of the inner product and the texture data, and wherein the.
[0017]
In the image generation device, the image output processor determines a mode of data read from the image memory, a circuit that outputs the texture address to the image memory, the normal vector and the light source. An inner product circuit for obtaining an inner product value of a vector, an integration circuit for multiplying the output of the inner product circuit and the RGB value, the RGB value, the texture data, the output data of the inner product circuit, and the integration A data selector circuit to which the output data of the circuit is input and selectively outputting data corresponding to the mode determined by the mode determination circuit.
Further, the circuit for outputting the texture address to the image memory may include a read address generator.
[0018]
The image generation method of the present invention corresponding to the above-described problem includes a process of writing data corresponding to each pixel and a pixel mode representing the meaning of the data in a display area of an image memory, and a process of writing the pixel mode stored in the display area. Determining a pixel mode of the data, and performing a predetermined process corresponding to the determined pixel mode to create an output image , wherein the pixel mode includes first to fourth pixel modes. In the first pixel mode, the first pixel mode writes an RGB value in the display area, and creates an output image based on the RGB value.In the second pixel mode, writes a texture address in the display area. Reads texture data from the image memory based on the texture address to create an output image In the third pixel mode, data of a normal vector of a vertex of a polygon is written in the display area, and an output image is created based on an inner product value of the normal vector and the light source vector. Then, a texture address and normal vector data of a polygon vertex are written in the display area, texture data is read from the image memory based on the texture address, and an inner product value of the normal vector and the light source vector is calculated. And generating an output image based on an integrated value of the texture data and the inner product value .
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below in detail with reference to the drawings.
[0021]
(1) Configuration of Image Generating Apparatus FIG. 1 in which parts corresponding to those in FIG. 9 are assigned the same reference numerals shows the overall configuration of an image generating apparatus 20 of the present invention. The image generation device 20 includes a CPU 2, a main memory 3, an image generation processor 21, an image memory 22, and an image output processor 23. The CPU 2, the main memory 3, and the image generation processor 21 are connected to the main bus 7, respectively. It can send and receive data. The image generation processor 21 is connected to an image memory 22 to which data is output, and the image memory 22 and the image output processor 23 are connected so that data can be exchanged therebetween. The output data is sent to a monitor or the like. Incidentally, the main memory 3 stores a program for generating an image.
[0022]
Next, an example of information stored in the image memory 22 is shown in FIG. Information stored in the image memory 22 includes four types of pixel modes (mode = 0 to 3). Each of these pixel modes represents the meaning of data stored in each pixel in the display area. For example, mode = 0 represents data of “RGB”, mode = 1 is “texture address”, mode = 2 is “normal vector”, and mode = 3 is data of “texture address and normal vector”. Each is represented.
[0023]
FIG. 3 shows the correspondence between the display area, the texture area, and the pixel mode. The pixel mode is mode = 0 to 3 as described above. mode = 0 represents the coordinate values (R, G, B) in the display area, and mode = 1 represents the number of pages Tp of the texture area as the texture address and the coordinate values (U, V) in the texture area. Further, mode = 2 represents a normal vector (Nx, Ny, Nz) in the display area, and mode = 3 represents the contents of mode = 1 and mode = 2, that is, the texture address and the normal vector.
[0024]
Here, FIG. 4 shows a configuration example of the image output processor 23.
The image output processor 23 includes a mode determination circuit 24, a read address generator 25, an inner product 26, a data selector 27, and an integrator 28. The mode determination circuit 24 receives data transmitted from the image memory 22 and outputs a mode determination result of the data to the data selector 27.
[0025]
If the data from the image memory 22 is mode = 0, it is output to the data selector 27, and if mode = 1, it is output to the data selector 27 and the address of the coordinate value (U, V) of the texture area is read. The address is output to the image memory 22 via the address generator 25. When the data from the image memory 22 is mode = 2, the inner product 26 is used to calculate the inner product of the normal vector (Nx, Ny, Nz) and the light source vector, which are the data from the image memory 22, and the data is sent to the data selector 27. Is output. Further, in the case of mode = 3, the inner product of the normal vector and the light source vector obtained in the same manner as in the case of mode = 2 and the mode = 0 of mode = 0 read from the image memory 22 using the texture address of mode = 1 The value obtained by multiplying the RGB value by the integrator 28 is output to the data selector 27.
The data selector 27 outputs, to the outside, data corresponding to the mode obtained from the determination result sent from the mode determination circuit 24 among the input data.
[0026]
FIG. 5 is a flowchart showing the procedure of the mode determination by the mode determination circuit 24 in the image output processor 23. First, the process starts at step SP1. In step SP2, a mode determination is performed, and when the determination result is mode = 0, the process proceeds to step SP3. At step SP3, the RGB values are written to the image memory 22, and at step SP4, the RGB values are read from the image memory 22, and the process proceeds to step SP5.
When the mode determination result of step SP2 is mode = 1, the process proceeds to step SP6, and the texture address is written in the image memory 22. Thereafter, the process proceeds to step SP7, where the RGB values are again read from the image memory 22 using the texture address read from the image memory 22, and the process proceeds to step SP5.
[0027]
Further, when the mode determination result is mode = 2, the process proceeds to step SP8, and the normal vector is written to the image memory 22. Thereafter, the process proceeds to step SP9, where the inner product of the normal vector and the light source vector read from the image memory 22 is set as an RGB value, and the process proceeds to step SP5.
Further, when the mode determination result is mode = 3, the process proceeds to step SP10, and the normal vector and the texture address are written in the image memory 22. Thereafter, the process proceeds to step SP11, where the inner product of the normal vector and the light source vector read from the image memory 22 is multiplied by the RGB value read using the texture address read from the image memory 22, and the process proceeds to step SP5.
Here, the RGB values are output in step SP5, and the processing ends in step SP12.
[0028]
(2-1) Case in which texture mapping is performed on a three-dimensional polygon In the above configuration, first, a case in which texture mapping is performed on a three-dimensional polygon will be described.
The CPU 1 outputs a drawing command to the image generation processor 21 in accordance with a program stored in the main memory 3, and the image generation processor 21 responds to the command to output a pixel value to be displayed in the display area 31 of the image memory 22. Is written in the texture area 32a in which is stored.
The image output processor 23 reads the display area 31 of the image memory 22 according to the video synchronization signal, and reads and outputs the texture pixel value from the texture area 32a of the image memory 22 according to the read texture address.
[0029]
FIG. 6 shows the memory area 30 by the processing performed by the image generation processor 21. Here, a case is shown in which the image generation processor 21 receives the vertex address and the texture address of the triangle and draws it on the image memory 22. The image generation processor 21 calculates the position at which the pixel value to be drawn is stored, that is, the texture address, from the positional relationship between the three vertices of the triangle ABC and the interior point E, and writes the texture address to the interior point E of the triangle ABC. .
[0030]
(2─2) Case where founshading is performed on a three-dimensional polygon Next, a case where founshading is performed on a three-dimensional polygon will be described. The main memory 3 stores a program for generating an image. The CPU 2 outputs a drawing instruction to the image generation processor 21 according to the program, and the image generation processor 21 writes the RGB values of the polygon and the normal vector of each point in the display area 31 of the image memory 22 in accordance with the instruction.
The image output processor 23 reads the display area 31 of the image memory 22 according to the video synchronization signal, and outputs a pixel value obtained by multiplying the RGB product of the polygon by the inner product of the read normal vector and light source vector.
[0031]
FIG. 7 shows the memory area 30 by the processing performed by the image generation processor 21. Here, the case where the image generation processor 21 receives the vertex address and the normal vector of the triangle and draws it on the image memory 22 will be described. The image generation processor 21 calculates a normal vector on a pixel to be drawn from the positional relationship between the three vertices of the triangle ABC and the interior point E, and writes the RGB values and the normal vector of the polygon to the interior point E of the triangle ABC.
[0032]
(2─3) A case where texture mapping is performed on a three-dimensional polygon and further shading is performed. Next, a case where texture mapping is performed on a three-dimensional polygon and further shading is described. The main memory 3 stores a program for generating an image. The CPU 2 outputs a drawing command to the image generation processor 21 according to the program, and the image generation processor 21 writes the address of the texture area in which the pixel value to be displayed is stored in the display area of the image memory 22 in accordance with the command.
Also, the normal vector of each point is written. The image output processor 23 reads the display area of the image memory 22 in accordance with the video synchronization signal, reads the texture pixel value from the texture area of the image memory 22 in accordance with the read texture address, and reads the inner product of the normal vector and the light source vector. Is multiplied by the texture pixel value and output as a pixel value.
[0033]
FIG. 8 shows the memory area 30 by the processing performed by the image generation processor 21. Here, a case is shown in which the image generation processor 21 receives a vertex address, a texture address, and a normal vector of a triangle and draws it on the image memory 22.
The image generation processor 21 calculates the position at which the pixel value to be drawn is stored, that is, the texture address, from the positional relationship between the three vertices of the triangle ABC and the interior point E, and writes the texture address to the interior point E of the triangle ABC. .
In addition, a normal vector on a pixel to be drawn is calculated, and the RGB value and the normal vector of the polygon are written at an inner point E of the triangle ABC.
[0034]
According to the above configuration, a part of the processing conventionally performed by the image generation processor before writing to the screen memory is performed after reading by the image output processor, so that the image data can be read from the texture area 32 without being read. The processing can be performed only by writing an address to the memory 22, thereby reducing the processing amount. That is, the image generation processor 21 can perform drawing only by writing to the display area 31. Also, in any case, the image output processor 33 only needs to process the number of pixels included in the display area 31, and even an image in which polygons are overlapped multiplexly can be displayed only by processing the number of pixels to be displayed. From the above, only the processing for the pixels to be finally displayed is required, so that the processing amount of the image data can be reduced.
[0035]
【The invention's effect】
As described above, according to the image generation device or the image generation method of the present invention, unnecessary data processing can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing the configuration of an image generating apparatus according to the present invention.
FIG. 2 is a chart showing an example of a pixel mode.
FIG. 3 is a schematic diagram for explaining a display area and a texture area in an image memory;
FIG. 4 is a schematic block diagram showing a configuration of an image output processor.
FIG. 5 is a flowchart illustrating a processing procedure based on mode determination of an image output processor.
FIG. 6 is a schematic diagram illustrating a memory area when texture mapping is performed on a three-dimensional polygon.
FIG. 7 is a schematic diagram showing a memory area when founseeing a three-dimensional polygon.
FIG. 8 is a schematic diagram illustrating a memory area when performing font mapping after texture mapping of a three-dimensional polygon.
FIG. 9 is a schematic block diagram showing a configuration of a conventional image generating apparatus.
FIG. 10 is a schematic diagram illustrating a memory area when texture mapping is performed on a three-dimensional polygon by a conventional image generation device.
FIG. 11 is a schematic diagram illustrating a memory area when performing three-dimensional polygon shading by a conventional image generation device.
FIG. 12 is a schematic diagram illustrating a memory area when performing font mapping after texture mapping of a three-dimensional polygon by a conventional image generation device.
FIG. 13 is a schematic diagram illustrating a polygon obtained by erasing a hidden surface.
[Explanation of symbols]
1 image generating apparatus, 2 CPU, 3 main memory, 4 21 image generating processor 5, 22 image memory 6, 23 image output processor 7, main bus 10, 30... Memory area, 11, 31... Display area, 12, 32.

Claims (4)

An image memory, an image generation processor that writes data corresponding to each pixel in the display area of the image memory and a pixel mode representing the meaning of the data, and reads the data and the pixel mode stored in the display area, An image output processor that determines a pixel mode of the read data and performs a predetermined process corresponding to the determined pixel mode to create an output image ;
The pixel modes include first, second, third, and fourth pixel modes,
In the first pixel mode, the image generation processor writes RGB values in the display area, and the image output processor creates an output image based on the RGB values,
In the second pixel mode, the image generation processor writes a texture address in the display area, and the image output processor reads texture data from the image memory based on the texture address to create an output image,
In the third pixel mode, the image generation processor writes data of a normal vector of a vertex of a polygon in the display area, and the image output processor outputs an output image based on an inner product value of the normal vector and the light source vector. To create
In the fourth pixel mode, the image generation processor writes a texture address and data of a normal vector of a vertex of a polygon in the display area, and the image output processor reads texture data from the image memory based on the texture address. An image generating device for calculating an inner product value of the normal vector and the light source vector, and creating an output image based on an integrated value of the texture data and the inner product value. The image output processor,
A mode determination circuit for determining a mode of data read from the image memory;
A circuit for outputting the texture address to the image memory;
An inner product circuit for calculating an inner product value of the normal vector and the light source vector,
An integrating circuit that multiplies the output of the inner product circuit by the RGB value;
The RGB value, the texture data, the output data of the inner product circuit, and the output data of the integrating circuit are input, and data for selectively outputting data corresponding to the mode determined by the mode determination circuit. and a selector circuit, the image generating apparatus according to claim 1. 3. The image generation device according to claim 2 , wherein the circuit that outputs the texture address to the image memory includes a read address generator. A process of writing data corresponding to each pixel and a pixel mode representing the meaning of the data in the display area of the image memory, and determining the pixel mode of the data from the pixel mode stored in the display area; Performing a predetermined process corresponding to the process of creating an output image, and an image generation method ,
The pixel modes include first, second, third, and fourth pixel modes,
In the first pixel mode, write an RGB value to the display area, and create an output image based on the RGB value;
In the second pixel mode, write a texture address in the display area, read texture data from the image memory based on the texture address to create an output image,
In the third pixel mode, while writing the data of the normal vector of the vertex of the polygon in the display area, create an output image based on the inner product value of the normal vector and the light source vector,
In the fourth pixel mode, a texture address and data of a normal vector of a vertex of a polygon are written in the display area, texture data is read from the image memory based on the texture address, and a texture vector and a light source vector are compared. calculating the inner product value, images generating method of creating an output image based on the integrated value of the inner product and the texture data.

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