KR100834938B1 - A light source parameter storage circuit of a three-dimensional graphic and a lighting processing calculation method using the light source parameter - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to illumination processing operations of three-dimensional graphics, and more particularly to a memory circuit for storing light source parameters corresponding to a plurality of light sources. A light source parameter storage circuit according to the present invention includes a memory section including a memory circuit for storing values of a plurality of light source parameters corresponding to a plurality of light sources, an initial value circuit for outputting initial values of the light source parameters, And a light source parameter selecting unit for selecting one of the read light source parameter values and the initial values and outputting the selected light source parameter values as the light source parameters. According to the present invention, by replacing the register circuit with a memory circuit, it is possible to reduce the circuit area used thereby contributing to miniaturization of the illumination processing circuit, process cost, and reduction of the process defect rate.

3D graphics, lighting processing, static RAM, SRAM, registers, circuit area.

Description

TECHNICAL FIELD [0001] The present invention relates to a light source parameter storage circuit for a three-dimensional graphic, and a lighting processing method using the light source parameter. [0002]

Figure 1 is a table showing the light source parameters supported by the OpenGL standard.

2 is a diagram showing the structure of a conventional light source parameter storage circuit using a register.

3 is a diagram illustrating a conventional circuit for selecting a light source parameter associated with a particular light source among light source parameters stored in a register.

4 is a diagram showing the structure of a light source parameter storage circuit according to the present invention using a static RAM.

5 is a diagram showing the configuration of the light source parameter storage circuit of FIG. 4 in more detail.

6 is a timing chart showing the operation timing of the light source parameter storage circuit according to the present invention.

FIG. 7 is a flowchart showing steps of an illumination processing operation method according to the present invention.

Description of the Related Art

410, 510: Static RAM memory unit

420: illumination parameter register

421, 540: Light source parameter register

430: Lighting processing unit

520: initial value circuit

530: Multiplexer

More particularly, the present invention relates to a method of saving the area of an illumination processing circuit by storing light source parameters using a memory circuit and a configuration of an illumination processing circuit to which the method is applied.

3D graphics technology refers to a technique of visualizing the shape, color, and movement of an object located in a three-dimensional space using a digital computer and three-dimensional software. 3D graphics technology has greatly developed thanks to the recent growth of the 3D game market, and it is also a key infrastructure technology already widely used in education, medical, military, and art fields.

3D graphics technology is widely used because it allows users to intuitively convey information by realistically displaying the object. 3D graphics operations are classified into coordinate transformation operations and illumination processing operations. In particular, lighting processing calculations make objects look more realistic by calculating lighting effects by the light source.

A three-dimensional graphic illumination processing operation uses a large number of parameters to calculate a lighting effect appearing at each vertex in a three-dimensional space by a light source at a specific location. FIG. 1 shows parameters used in an illumination processing operation in a widely used graphic library OpenGL (Open Graphics Library).

As shown in Figure 1, OpenGL supports up to eight light sources. Therefore, the parameter storage space for supporting illumination processing operations based on the above parameters is 408 bits for material parameters, 4608 bits for light source parameters, parameter, which has a size of 96 bits.

Figure 2 is a diagram illustrating a conventional circuit for storing such lighting parameters. Referring to FIG. 2, a conventional illumination parameter storage circuit stores a lighting parameter using a register. The illumination parameter register 210 for storing illumination parameters is divided into a material parameter register 211, a light source parameter register 212, and an illumination model parameter register 213 according to the type of a parameter to be stored.

The illumination processing arithmetic unit 220 reads the illumination parameters 214 from the illumination parameter register 210, performs an illumination processing operation on the basis of the illumination parameters 214, and outputs the arithmetic operation result 221. The illumination parameters 214 read from the illumination parameter register 210 for the illumination processing operation include the material parameters read from the material parameter register 211, the light source parameters for the specific light source read from the light source parameter register 212, And at least one of the illumination model parameters read out from the model parameter register 213.

3 is a diagram showing in more detail the internal configuration of the light source parameter register 212 among the circuits shown in FIG. 3 illustrates a register circuit for storing a _cli indicative of ambient light intensity, but the structure shown in Fig. 3 is equally applicable to a register circuit for storing other light source parameters.

Referring to FIG. 3, the ambient light intensity parameter register 310 includes eight 96-bit registers that store eight light sources and associated ambient light intensity parameters, respectively. The ambient light intensity parameter register circuit shown in FIG. 3 selects one of eight register outputs according to a predetermined selection signal 301 in order to select and output a parameter related to a specific light source among the eight registers And a multiplexer 320. Thus, the light source parameter 321 output by the multiplexer 320 is used to calculate the effect of one of the eight light sources.

The conventional light source parameter storage circuit described with reference to FIG. 2 and FIG. 3 is a circuit in which a plurality of light source parameters associated with a plurality of light sources are stored Lt; / RTI > source parameter registers. Accordingly, in the case where eight light sources are supported as described above, the light source parameter register occupies about 90% of the total illumination parameter registers, and the light source register corresponding to 1/8 of the total light parameter registers occupies a specific light source There is a problem in that the register space can not be used efficiently because it is not used in performing the illumination processing operation on the memory space.

As will be appreciated, the resistors have a relatively large circuit area compared to memory circuits. Thus, relying solely on registers to store such a large number of illumination parameters makes it difficult to reduce the area of the illumination parameter storage circuitry, and thus the overall circuitry of the lighting processor.

In order to solve the above problems, the present invention proposes a new technique for reducing the area of the light source parameter storage circuit occupying most of the illumination parameter storage circuit.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the area of an illumination parameter storage circuit.

Specifically, the present invention aims at saving circuit space occupied by a light source parameter storage circuit by using a memory circuit for storing a light source parameter occupying most of illumination parameters.

It is another object of the present invention to reduce the area of the light source parameter storage circuit, thereby achieving miniaturization and high integration of the illumination parameter storage circuit and further the entire illumination processor.

It is another object of the present invention to reduce the process cost and the process defect rate by reducing the area of the light source parameter storage circuit.

In addition, the present invention includes an initial value circuit for outputting an initial value of a light source parameter by constructing a light source parameter storage circuit using a memory circuit, thereby effectively supporting a three-dimensional graphic standard library having an initial value defined do.

According to an aspect of the present invention, there is provided a light source parameter storage circuit including a memory unit including a memory circuit for storing values of a plurality of light source parameters corresponding to a plurality of light sources, An initial value circuit for outputting an initial value of the light source parameter and a light source parameter value corresponding to any one of the plurality of light sources from the memory unit and selecting any one of the read light source parameter value and the initial value, And a light source parameter selection unit for outputting the light source parameter.

According to another aspect of the present invention, there is provided an illumination processing method including storing a plurality of light source parameters corresponding to a plurality of light sources in a memory circuit, reading a value of a light source parameter corresponding to one of the plurality of light sources from a memory circuit Selecting one of a predetermined initial value and a readout light source parameter value output by the initial value circuit and generating an illumination processing operation result using the selected light source parameter value .

Hereinafter, a configuration of a light source parameter storage circuit and an illumination processing calculation method based on the light source parameters according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a diagram showing a structure of an illumination processor including a light source parameter storage circuit according to the present invention. Figure 4 illustrates a circuit for storing light source parameters for eight light sources as supported by OpenGL. However, as will be apparent to those skilled in the art, the scope of the present invention is not limited to a circuit that supports eight light sources, but is applied to a general light source parameter storage circuit that supports a plurality of light sources.

Referring to FIG. 4, the illumination parameters are stored in the illumination parameter register 420 and input to the illumination processing unit 430. The illumination parameter register 420 includes a material parameter register, a light source parameter register 421, and an illumination model parameter register. However, the light source parameter register 421 is not for storing all the light source parameters for supporting all the eight light sources as in the prior art, but for temporarily storing only the light source parameters used in the illumination processing operation associated with the specific light source .

On the other hand, the total light source parameters associated with the eight light sources are stored in a static random access memory (SRAM) As described above, the total light source parameters for supporting all the eight light sources are stored in the SRAM, and only a part of the light source parameters necessary for performing the illumination processing operation associated with the specific light source is temporarily stored in the register 421, The number of the light source parameter registers 421 can be reduced to one eighth as compared with the conventional one. This also means that the total number of illumination parameter registers is reduced by 80% compared to the conventional one. It has been confirmed that such a storage circuit configuration can reduce the total illumination processor area by about 10 to 20%.

However, by replacing a large part of the conventional light source parameter register with the SRAM, additional circuitry is required to support the light source parameter initial value specified in the standard such as OpenGL. For example, since OpenGL defines different initial values of diffuse intensity and specular intensity among the light source parameters for the 0th light source and the other light sources, OpenGL uses a single light source parameter register 421 These different initial values can not be supported. Thus, an initial value circuit that supports these different initial values is needed.

5 is a diagram showing the configuration of the light source parameter storage circuit shown in FIG. 4 in more detail. 5 and the following description are limited to a register circuit for storing the ambient light intensity parameter a _cli for the sake of clarity, but the structure shown in Fig. 5 is equally applicable to a register circuit for storing other light source parameters. A resistor circuit having such a structure is applied to a circuit for storing, for example, diffuse intensity, specular intensity, position of a light source, spot light direction of a light source, and various attenuation coefficients.

The light source parameter storage circuit of FIG. 5 includes an SRAM memory unit 510 that stores all the ambient light parameters for the eight light sources. The SRAM memory unit 510 includes a total of 768 bits of SRAM for storing eight ambient light parameters ranging from 0 to 7 having a length of 96 bits.

In addition, the light source parameter storage circuit includes an initial value circuit 520. [ The initial value circuit 520 consists of fixed logic that outputs an initial value of the ambient light parameters. According to one embodiment, the initial value circuit 520 includes circuitry for determining and outputting an initial value of each bit of the ambient light parameter with a pull-up or pull-down resistor.

The multiplexer 530 receives the output of the SRAM memory unit 510 and the output of the initial value circuit 520 as input signals, and selects one of the signals as an input signal. The selection signal 501 for selecting one of the user input parameter value stored in the SRAM memory unit 510 and the initial value fixed on the circuit is referred to the value of the status register indicating the number and the number of the used light source Lt; / RTI >

The light source parameter values selected and outputted by the multiplexer 530 are stored in the light source parameter register 540 and read out from the light source parameter register 540 by the illumination processing arithmetic unit 430. [

In the case of the ambient light intensity parameter illustrated in FIG. 5, only one initial value is specified on the OpenGL standard, so that the initial value circuit 520 consists of a single logic. However, in the case of the diffuse intensity parameter or the specular intensity parameter, the initial value circuit 520 is composed of two different logic because the 0th light source and the other light sources are specified in the OpenGL standard so that they have different initial values. Accordingly, the multiplexer 530 is configured to select one of three input signals including the output signal of the SRAM memory unit 510 and the output signal of the two initial value circuits 520, The selection signal generation logic may have different values depending on the case of selecting the initial value of the light source and the case of selecting the initial values of the other light sources.

The light source parameter storage circuit according to the present invention can effectively support a graphic library standard that defines initial values of light source parameters such as OpenGL while replacing a substantial portion of the light source parameter registers with SRAM by including the initial value circuit.

In addition, if the register is replaced with the SRAM, the operation cycle may also be changed for reading the normal light source parameter. For reference, the term "cycle" as used herein means a period of operation of a functional block of a circuit, and may be defined as one or more internal operation clocks. Alternatively, if the circuit is configured to respond to both the rising edge and the falling edge, the cycle may be defined as a half clock.

6 is a timing chart showing the operation timing of the light source parameter storage circuit according to the present invention. 6 illustrates a case where the operation cycle of the SRAM memory unit 510 and the light source parameter register 540 is one clock.

In the case of storing the light source parameters of all the eight light sources directly in the register as in the prior art, an output enable (OEN) signal is applied to the light source parameter register one cycle before the illumination processing operation, Value could be output to the register output port before the start of the lighting processing operation.

However, such a timing can not be applied as it is in the structure as shown in Fig. 6 is a timing chart showing the timing of the enable signal for stably reading the light source parameters in the structure shown in FIG.

The SRAM output enable signal 602 applied to the SRAM memory unit 510 and the register output enable signal 603 applied to the light source parameter register 540 are input to the clock signal 601 Synchronized. However, the present invention can also be applied to a case where at least one of the output enable signals 602 and 503 is not synchronized with the clock signal 601 because of performance optimization or the like.

6, the register output enable signal 603 may be applied at least one cycle before the execution cycle of the first illumination processing operation 604 to read the light source parameter value temporarily stored in the light source parameter register 540 . In order to ensure that the light source parameter value stored in the light source parameter register 540 and read by the register output enable signal 603 is a valid value read out from the SRAM memory unit 510, the SRAM output enable signal 602 Is applied at least one cycle before the register output enable signal 603, that is, at least two cycles before the execution cycle of the illumination processing operation 604. [ The operation of the initial value circuit 520 and the multiplexer 530 is not synchronized with the clock signal 601, so that the timing is not taken into consideration. Assume, however, that the output signal setup and hold time of the multiplexer 530 is much shorter than the period of the clock signal 601.

The light source parameter storage circuit according to the present invention may be realized by a combination of various types of digital circuits and analog circuits, and may be implemented by an integrated circuit (IC) chip produced by a test process or a mass production process, (Intellectual Property) core or the like. Accordingly, the present invention is applied to all the products provided in the above-mentioned form, similar form, or intermediate form thereof.

Meanwhile, FIG. 7 is a flowchart showing the lighting processing operation method according to the present invention step by step.

Step S710 of FIG. 7 is a step of storing a plurality of light source parameters corresponding to a plurality of light sources in the SRAM. This step can be entered by the user using the API functions, and the user can use a part of the storage space provided for a plurality of light sources or the entire storage space by designating the light source to be used. Therefore, this step is not necessarily applied to an illumination processing operation in which a plurality of light sources are applied, and it is common in the case of storing light source parameters of a desired light source in all or a part of an SRAM memory space storing light source parameters for a plurality of light sources . It is therefore clear that this step can also be applied to the case of using one light source.

In step S720, the light source parameter value corresponding to the specific light source is read out from the SRAM. The output enable signal of the SRAM is applied while the address value of the SRAM memory storing the light source parameter is stored in the address line of the SRAM in order to read the light source parameter.

Subsequently, in step S730, an initial value signal output by the initial value circuit and a light source parameter value read by the step S720 are selected and output. Such a selection may be performed by a selection circuit composed of a multiplexer or the like, and the initial value circuit may consist of fixed logic outputting a fixed signal value.

Finally, in step S740, the illumination processing operation is performed using the light source parameter values selected and output in step S730. The illumination processing operation can be performed by substituting the light source parameter values into a predetermined illumination processing expression provided by a graphics library such as OpenGL. As a result of such an operation, an illumination processing operation result is generated.

According to one embodiment, step S730 is performed at least one cycle before step S740, so that the output signal value by step S730 is used by step S740. Also, step S720 is performed at least one cycle before step S730, so that the output signal value by step S720 is used by step S730. That is, step S720 is performed at least two cycles before step S740.

The steps S720 to S740 are the steps of performing illumination processing operations related to a specific one of the plurality of light sources. Therefore, according to another embodiment of the present invention, the steps S720 to S740 may be repeatedly performed for each of the plurality of light source parameters, so that a lighting effect collectively represented by a plurality of light sources can be calculated.

The illumination processing calculation method according to the present invention has been described with reference to FIG. Since details of the embodiments described above with reference to FIGS. 2 to 6 can be directly applied to the illumination processing operation method according to the present invention, detailed description related to the present method will be omitted.

In the present invention, the memory for storing the light source parameters included in the present invention is limited to the static RAM. However, the present invention can be applied to all kinds of memories having a constant read cycle, for example, a dynamic random access memory (DRAM) Volatile Random Access Memory), and flash memory.

The illumination processing calculation method and the light source parameter storage circuit generation method according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic recording media such as magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, magnetic recording media such as floppy disks, Optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

The medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, or the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

The light source parameter storage circuit according to the present invention can save the circuit area occupied by the light source parameter storage circuit by replacing the register circuit of the circuit that stores the light source parameter occupying most of the illumination parameters with the memory circuit.

Further, according to the present invention, it is possible to achieve miniaturization and high integration of the illumination parameter storage circuit and further the entire illumination processor according to the area reduction of the light source parameter storage circuit. Also, if the circuit area is reduced, the process cost and the process defect rate can be reduced.

In addition, according to the present invention, it is possible to effectively support a three-dimensional graphic standard library that defines an initial value by including an initial value circuit that outputs an initial value of a light source parameter.

Claims (14)

1. A circuit for storing a light source parameter used in a three-dimensional graphic illumination processing operation, A memory unit including a memory circuit for storing values of a plurality of light source parameters corresponding to a plurality of light sources; An initial value circuit for outputting an initial value of each of the plurality of light source parameters; And A memory for storing a first light source parameter value corresponding to one of the plurality of light sources and a second light source parameter for selecting one of the first light source parameter value and the initial value, The parameter selector And a light source parameter storage circuit for storing the light source parameter. The method according to claim 1, Wherein the light source parameter selector comprises: A multiplexer for selecting one of an output signal of the memory unit and an output signal of the initial value circuit and outputting the selected signal; And A register for receiving and storing a signal selected by the multiplexer, And a light source parameter storage circuit for storing the light source parameter. The method according to claim 1, Wherein the light source parameter selection unit reads the value of the first light source parameter from the memory unit at least two cycles before the three-dimensional graphic illumination processing operation is performed, Wherein the controller selects one of the read first light source parameter value and the initial value. The method according to claim 1, Wherein the initial value circuit outputs the initial value using a pull-up resistor or a pull-down resistor. Claim 5 has been abandoned due to the setting registration fee. The method according to claim 1, Wherein the plurality of light source parameters include at least one of an ambient light intensity, a diffuse intensity, a specular intensity, a position of a light source, a spot light direction of a light source, and attenuation coefficients. Claim 6 has been abandoned due to the setting registration fee. The method according to claim 1, Wherein the plurality of light source parameters are used to calculate a lighting effect at a vertex in three-dimensional space. Claim 7 has been abandoned due to the setting registration fee. The method according to claim 1, In an illumination processing operation method using a light source parameter, A first step of storing a plurality of light source parameters corresponding to a plurality of light sources in a memory circuit; A second step of reading a value of a first light source parameter corresponding to one of the plurality of light sources from the memory circuit; A third step of selecting any one of the predetermined initial value outputted by the initial value circuit and the read-out first light source parameter value as the second light source parameter; And And a fourth step of generating an illumination processing operation result using the selected second light source parameter value Wherein the illumination processing method comprises the steps of: 9. The method of claim 8, Wherein the third step is performed at least one cycle before the fourth step. 9. The method of claim 8, Wherein the second step is performed at least one cycle before the third step. 9. The method of claim 8, And the second to fourth steps are repeatedly performed for each of the plurality of light source parameters. Claim 12 is abandoned in setting registration fee. 9. The method of claim 8, Wherein the plurality of light source parameters include at least one of an ambient light intensity, a diffuse intensity, a specular intensity, a position of a light source, a spot light direction of a light source, and attenuation coefficients. Claim 13 has been abandoned due to the set registration fee. 9. The method of claim 8, Wherein the memory circuit is a static ram memory circuit. A computer-readable recording medium recording a program for executing the method according to any one of claims 8 to 13.

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