KR100885547B1 - Method of forming 3D graphics for interactive digital broadcasting and system of forming 3D graphics using the method - Google Patents

Abstract

The present invention relates to a three-dimensional graphics forming method and a video system using the same to improve the processing speed by reducing the data throughput in digital interactive broadcasting, the method and system is necessary to form a three-dimensional graphics to be displayed on the final display unit It includes a filtering function to reduce the amount of information of the missing three-dimensional object.

Digital Interactive Broadcast, 3D Graphics, Transparent, Filtering

Description

Method of forming 3D graphics for interactive digital broadcasting and system of forming 3D graphics using the method

1 is a flowchart illustrating a 3D graphics forming method for digital interactive broadcasting according to the present invention.

2 is a diagram for describing a technique of determining a visible screen of a 3D object.

3 is a block diagram showing a three-dimensional graphics system for digital interactive broadcasting according to the present invention.

4 is a diagram illustrating a network of a 3D graphics system for digital interactive broadcasting according to an embodiment of the present invention.

5 is a diagram illustrating a network of a 3D graphics system for digital interactive broadcasting according to another embodiment of the present invention.

6 is a photograph showing three-dimensional graphics formed by a three-dimensional graphics forming method for digital interactive broadcasting according to the present invention.

** Brief description of symbols for the main parts of the drawing **

110: modeling unit 120: filtering unit

130: rendering unit 131: coordinate conversion unit

132: lighting control unit 133: projection unit

134: resolution control unit 135: optimal screen determination unit

140: display unit 150: input unit

The present invention relates to a method for forming 3D graphics suitable for digital interactive broadcasting and a system using the same.

Since we live in a three-dimensional world, we must express three-dimensional representations of the world with space. However, the current screen output of the display device is made in a two-dimensional plane, it is difficult to express the feeling or perspective like a real object. Thus, by projecting a three-dimensional space to a two-dimensional plane in a certain point of view, it is possible to express the three-dimensional space on a display device such as a monitor or a CRT. do.

On the other hand, with the development of digital technology, there has been developed an interactive broadcast that can be transmitted in both directions between the provider for transmitting the broadcast and the user watching the received broadcast. In such interactive broadcasting, modeling and rendering of 3D graphics is essential in order to display more realistic images. However, there are limitations in implementing three-dimensional graphics in a digital interactive broadcasting system such that there is a large amount of information and the computational processing speed is delayed during rendering.

The present invention is to provide a three-dimensional graphics forming method suitable for interactive digital broadcasting by reducing the capacity of the memory and a three-dimensional graphics forming system using the same.

In addition, the present invention is to provide a three-dimensional graphics forming method and a three-dimensional graphics forming system that can implement the desired three-dimensional graphics by reducing the data throughput to improve the processing speed, prevent image distortion phenomenon in the display unit .

The present invention is to determine whether the three-dimensional object is transparent, if the determination results in the transparent three-dimensional object based on the first information constituting the three-dimensional object, otherwise the visible screen of the three-dimensional object It provides a 3D graphics forming method for digital interactive broadcasting comprising the step of rendering based on the second information constituting.

In the method of forming a 3D graphic, if the determination result is not transparent, the method may further include determining a visible screen of the 3D object. Visible screen determination can be made by reading the back-face of the 3D object and removing the back.

In the 3D graphic forming method, the second information may be generated by selectively adopting information constituting the visible screen from the first information. In other words. The second information excludes third information constituting the rear surface from the first information. Therefore, the second information has a smaller information amount than the first information.

In the 3D graphic forming method, the first information may include transparent information of the 3D object. Therefore, it is determined that the 3D object is not transparent according to the transparent information, and if it is transparent, it is rendered by projecting on the 2D plane based on the first information, or when it is not transparent, it is projected on the 2D plane based on the second information. can do.

The transparent information may be automatically generated, or may be generated by an input of a provider that transmits information configuring the 3D object or by an input of a user receiving information configuring the 3D object.

The present invention also provides a method for forming a 3D graphic for transmitting a 3D graphic for the digital interactive broadcast to a user's receiving terminal, and forming the 3D graphic according to the method in the receiving terminal. Provides a method of forming a dimensional graphic.

In addition, the present invention provides a recording medium that records the three-dimensional graphics forming method for digital interactive broadcasting described above.

In addition, the present invention provides a modeling unit for generating a first information constituting a three-dimensional object, and determines whether the three-dimensional object is transparent, and if the transparent supply the first information, if not transparent of the three-dimensional object The present invention provides a 3D graphic forming system for a digital interactive broadcast including a filtering unit for supplying second information constituting a visible screen and a rendering unit for rendering the first information or the second information supplied from the filtering unit.

In the 3D graphic forming system, the modeling unit generates first information including transparency information of the 3D object. The transparent information may be automatically generated, or may be generated by an input of a supplier transmitting 3D graphics or by an input of a user receiving 3D graphics.

In the 3D graphic forming system, the filtering unit includes a determination unit that determines whether the 3D object is transparent, and a control unit which supplies first information or second information according to the determination unit. In particular, if the 3D object is transparent according to the result of the determination unit, the controller supplies the first information as it is; otherwise, selects and supplies the second information constituting the visible screen of the 3D object from the first information.

In the 3D graphic forming system, the rendering unit converts the supplied information from one coordinate system to another coordinate system, an illumination control unit for calculating the influence of the light source based on the information calculated by the coordinate conversion unit and the And a projection unit for projecting the information transmitted from the illumination control unit to the two-dimensional plane.

The rendering unit may further include a resolution control unit which selects only an image of a visible region corresponding to a predetermined resolution in a 3D graphic projected on a 2D plane, and an optimum screen determination unit that corrects a color changing in the display unit. The 3D graphic may be displayed on the display unit more realistically according to the resolution control unit and the optimum screen determination unit.

In the 3D graphic forming system, the 3D graphic forming system for digital interactive broadcasting may be classified into a digital interactive broadcast transmitting apparatus and a digital interactive broadcasting receiving terminal.

The filtering unit may be provided in the transmitting device or may be provided in the receiving terminal. When the filtering unit is provided in the transmitting device, the supply side for supplying information constituting the 3D object determines whether the 3D object is transparent, and if it is not transparent, supplying the second information with a relatively small amount of information to the terminal, The side receives a small amount of information and computes it, so that 3D graphics can be implemented at high speed.

In addition, by including the coordinate conversion unit, the lighting control unit, and the projection unit of the filtering unit and the rendering unit in the transmitting apparatus, information constituting the three-dimensional object projected on the two-dimensional plane can be supplied to the receiving terminal side. By providing a resolution control unit and an optimum screen determination unit which are the remaining parts of the rendering unit, it is possible to control to supply a 3D graphic suitable for the display unit.

Alternatively, when the filtering unit is provided in the receiving terminal, all of the first information constituting the 3D object is received, but the filtering unit selectively supplies only the second information so that the rendering unit having the most influence on the speed reduces the amount of information. Since only the second information having the twisted pair processing is possible in this case, it can also contribute to an increase in speed.

Hereinafter, with reference to the accompanying drawings the present invention will be described in more detail.

1 is a flowchart illustrating a 3D graphics forming method for digital interactive broadcasting according to the present invention.

Referring to FIG. 1, a target for displaying a 3D graphic is specified by generating first information constituting a 3D object (S10). The first information includes three-dimensional environment information, three-dimensional geometry information, color information, texture information, and the like. In addition, the first information includes transparent information.

The three-dimensional environment information is information for constructing a virtual three-dimensional environment in the receiving terminal and relates to a coordinate system, lighting, a camera, and the like. The 3D geometric information refers to information constituting the 3D object, the color information refers to information representing the color of the 3D object, the texture information refers to information representing the texture. In addition, the transparent information refers to information representing transparency of a 3D object as a kind of color information.

In operation S20, it is determined whether the 3D object is transparent. The determination may be determined based on the transparent information, and the transparent information may be automatically generated or a user's input for transmitting information constituting the 3D object or a user receiving information constituting the 3D object. Can be generated by

On the basis of the transparent information, if the 3D object is transparent, rendering is performed based on the first information constituting the 3D object (S30). Alternatively, if the 3D object is not transparent based on the transparent information, a visible screen of the 3D object is determined (S40).

Determining the visible screen is to remove the surfaces constituting the back-face of the 3D object based on a predetermined time point (Back-Face Culling). Referring to FIG. 2, all three-dimensional objects of the cube are composed of 12 triangular polygons, but only 6 polygons are rendered. In other words, the amount of data to be processed can be reduced by almost half in all operations that need to be performed later, thereby ensuring a high speed.

To determine the visible screen, first of all, the rear surface of the 3D object must be read. In detail, the reading method may determine a rear surface by calculating a normal vector of a polygon and a normal vector facing to a viewpoint. In addition, the rear surface may be determined using a plane constant, which is determined based on only the plane constant, so that no additional operation is required, so that the visible screen determination speed may be increased.

Hidden-surface culling can also be used as a visual screening technique. Hidden face removal removes the information of the hidden part when the 3D object placed behind is covered by the 3D object placed in front when the 3D object is plural, thus reducing the amount of information to be calculated later. have. In general, the hidden surface removal is performed in the rendering step.

After determining the visible screen of the 3D object, second information constituting the visible screen is selected from the first information (S50). The operation may generate second information by removing third information corresponding to the rear surface of the 3D object from the first information.

Then, rendering is performed based on the second information (S60). The second information has a smaller amount of information than the first information. In particular, in the case of the 3D object as shown in FIG.

The three-dimensional graphic forming method for the digital interactive broadcast described above is recorded by a recording medium, and the method may be installed in a broadcast transmitting device or a receiving terminal using the recording medium. In addition, when it is difficult to install in the receiving terminal through the recording medium, the receiving apparatus receives information on configuration or configuration of the 3D object to be implemented and the 3D graphic forming method for the digital interactive broadcasting. When received by the terminal, the receiving terminal may form three-dimensional graphics in real time according to the above method only when necessary.

The method is generally a somewhat passive structure of the transmitting device or the like, it is difficult to configure and change a part of the recording medium, or the method of using the present invention in an environment where it is difficult to have a device having a high performance of the receiving terminal. Is preferred.

3 is a block diagram showing a three-dimensional graphics system for digital interactive broadcasting according to the present invention.

Referring to FIG. 3, the 3D graphics system includes a modeling unit 110, a filtering unit 120, a rendering unit 130, a display unit 140, and an input unit 150.

The modeling unit 110 forms information constituting a 3D object and information on configuring a virtual 3D environment in the receiving terminal. The information is referred to as first information, and the first information includes three-dimensional environment information, three-dimensional geometry information, color information, texture information, and the like.

The first information is transmitted to the filtering unit 120. The filtering unit 120 supplies the determination unit 121 that determines whether the 3D object is transparent and the second information corresponding to the first information or the visible screen of the 3D object according to the result of the determination unit 121. The control part 122 is provided.

The determination unit 121 may determine whether the 3D object is transparent according to the transparency information over the transparency of the 3D object in the first information. When the determination unit 121 determines that the 3D object is transparent according to the transparent information, the determination unit 121 generates a first control signal corresponding to the determination and supplies the first control signal to the control unit 122. The controller 122 supplies the first information to the renderer 130 according to the first control signal.

In addition, when the determination unit 121 determines that the 3D object is not transparent according to the transparent information, a second control signal corresponding to the determination is generated and the second control signal is supplied to the control unit 122. The controller 122 determines a visible screen of the 3D object according to a second control signal, selects second information constituting the visible screen, and supplies the selected second information to the renderer 130.

As a method of determining a visible screen, a method of removing faces constituting the back-face of a 3D object based on a predetermined viewpoint may be used. The back-face may use a plane constant or a polygon. It may be determined by calculating a normal vector of and a normal vector toward a viewpoint. In addition, a process of removing the hidden surface (Hidden-surface culling) may be additionally performed by the visible screen determination method.

The rendering unit 130 supplied with the first information or the second information renders based on the information. The renderer 130 may include a coordinate converter 131, an illumination controller 132, and a projector 133.

In detail, the coordinate converting unit 131 converts a vertex or a polygon constituting the supplied first information or the second information from one coordinate system to another through a matrix operation. Do it. The model coordinate is a reference coordinate system used when constructing a 3D object and converts a plurality of objects having different model coordinate systems into a world coordinate system to move to the same coordinate system. The object is then converted back to the camera coordinate system to project the objects moved to the world coordinate system. In addition, the vertex and polygon normal vector required for the lighting module are also processed by the coordinate converter 131 and transmitted to the lighting controller 132.

The lighting controller 132 calculates the influence of the light source based on the vertex and polygon normal vector calculated by the coordinate converter 131. The lighting controller 132 is in charge of basic calculation of color and shading of polygons and basic operations for applying them according to shading options. Types of lighting include point lights, parallel lights, directional lights, and the like.

The projection unit 133 is responsible for projecting three-dimensional coordinates (x, y, z) constituting the first information or the second information to two-dimensional graphics plane coordinates (x, y). In addition, the projection unit 133 may also perform operations such as shading and texture mapping.

In addition, the renderer 130 includes a resolution controller 134 and an optimum screen determiner 135. The resolution control unit 134 uses a field of view (FOV) to embrace different resolutions. According to the FOV, a vertical and horizontal ratio corresponding to a desired resolution is set using a proportional expression, and a screen corresponding to the ratio is configured. When the screen is configured as described above, the image is not distorted when the 3D object is enlarged or reduced, and the resolution can be freely set.

Also, the rendering unit 130 may perform a clipping operation to remove an area that does not correspond to the screen, that is, an area not included in the visible area. Clipping is the task of selecting only the 2D image in the visible region from the projected image on the 2D plane based on the information constituting the 3D object. If only a part of the 2D image is included in the visible region, it may be differentially applied through a shading technique.

The optimum screen determiner 135 performs color processing of the 2D image implemented in the 2D plane to form a more realistic 3D graphic. In detail, color processing may be performed by dithering and a neighbor color match technique based on a color look-up table (CLUT). In addition, the display unit 140 converts the 3D graphics supplied from the rendering unit 130 and displays the distorted image. Accordingly, the optimal screen determiner 135 also performs correction in consideration of the image distortion of the display 140. That is, by correcting the distortion in the optimum screen determination unit 135, the 3D graphic supplied from the optimum screen determination unit 135 may display a desired image after conversion in the display unit 140.

As the display unit 140, various devices such as a cathode ray tube (CRT), a plasma display device (PDP), a liquid crystal display device (LCD), and an organic light emitting display device (OLED) may be used. Depending on the device, different resolutions or image distortions may be corrected by the resolution determiner 134 and the optimum screen determiner 135, respectively.

The input unit 150 generates an input signal of a user who receives and views 3D graphics, and may allow the modeling unit 110 to generate transparent information of the 3D object by the user's input. That is, when the user wants to watch the 3D graphic, the input signal may be generated to provide transparent information, and the 3D graphic may be displayed based on the transparent information.

In addition, the input unit 150 may control the filtering unit 120 and the rendering unit 130. In detail, the input unit 150 may control the filtering unit 120 to filter for transparent processing. In addition, the inputter 120 may control the rendering unit 130 to move, rotate, enlarge, and reduce the 3D object, and to control functions such as resolution and lighting in the 3D environment.

4 is a diagram illustrating a network of a 3D graphics system for digital interactive broadcasting according to an embodiment of the present invention.

Referring to FIG. 4, a digital interactive broadcast transmitting device 200 and a digital interactive broadcast receiving terminal 300 are provided. The transmitter 200 and the receiver terminal 300 may provide an advanced interactive broadcast program using a digital broadcast application.

The transmitting device 200 includes a modeling unit 110 for generating first information constituting a 3D object. Then, the first information is transmitted to the receiving terminal 300, and the receiving terminal 300 renders the received information.

In detail, the receiving terminal 300 includes a filtering unit 120 and a rendering unit 130. In particular, by providing the filtering unit 120, it is determined whether the three-dimensional object is transparent to supply the first information if transparent, otherwise supplying the second information constituting the visible screen of the three-dimensional object after The amount of information processed by the renderer 130 may be reduced. The rendering unit 130 is a module that performs a large number of complex operations. The rendering unit 130 may improve the operation speed by receiving the information amount reduced by the filtering unit 120.

The 3D graphic processed by the digital interactive broadcast receiving terminal 300 may be displayed on the TV 141 which is the final display unit.

The user may be controlled to display the 3D graphic by inputting the user through the remote controller 151 which is an input unit.

FIG. 5 is a diagram illustrating a network of a 3D graphics system for digital interactive broadcasting according to another embodiment of the present invention, and includes a filtering unit 120 in the digital interactive broadcasting transmission device 210. Therefore, the amount of information transmitted to the digital interactive broadcast receiving terminal 310 during digital interactive broadcasting can be reduced.

In detail, when the 3D object is not transparent, the filtering unit 120 supplies second information constituting the visible screen of the 3D object, and the second information is transmitted by the digital interactive broadcast type broadcasting transmitter 210. Is transmitted to the receiving terminal 310 side. Therefore, by selecting and transmitting only the second information constituting only the visible screen of the 3D object from the first information constituting the entire 3D object, the amount of information transmitted to the receiving terminal 310 can be reduced. The rendered information is rendered by the rendering unit 130 of the receiving terminal 310.

Alternatively, in the present invention, the modeling unit 110, the filtering unit 120, and the coordinate converting unit 131, the lighting control unit 132, and the projection unit 133 of the rendering unit 130 may be used. By providing, the 3D graphic projected on the 2D plane can be supplied to a receiving terminal. In addition, the receiving terminal may control to display a desired 3D graphic by correcting the received 3D graphic appropriately on the display unit by including the resolution control unit 134 and the optimum screen determination unit 135 of the rendering unit 130. have.

Alternatively, the present invention may include both the modeling unit 110, the filtering unit 120, and the rendering unit 130 in the digital interactive broadcast receiving terminal. In addition, by receiving a driving signal or additionally necessary or updated 3D information from a transmitting device, the 3D object is modeled, only information corresponding to a visible screen is selected, and the information is rendered. It can be implemented to be displayed in.

Figure 6 is an embodiment of the three-dimensional graphics formed by the three-dimensional graphics forming method for the digital interactive broadcast according to the present invention, the result of producing a three-dimensional tetris.

The three-dimensional Tetris shown in FIG. 6 displays an opaque three-dimensional object having no rear surface, and displays only the second information corresponding to the visible screen of the Tetris. Therefore, it is possible to display three-dimensional graphics by optimizing for digital interactive broadcasting by reducing the amount of information and increasing computation speed.

 Although the present invention has been described with reference to the above-described embodiments, these are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, the 3D graphics forming method of the present invention and the system using the same by removing the rear surface of the 3D object is opaque by selecting only the second information constituting the visible screen and by processing the second information Can increase the processing speed. Therefore, it can be usefully used for digital interactive broadcasting such as three-dimensional user interface (UI), T-game by reducing memory capacity.

In addition, the present invention improves the processing speed by operating only the second information having a relatively small amount of information, and corrects in consideration of image distortion in the display unit, thereby enabling the digital display to implement three-dimensional graphics of a desired image in the final display unit. It is possible to provide a three-dimensional graphics forming system for broadcasting.

Claims (12)

Determining whether the 3D object is transparent; If transparent, rendering the first information constituting the 3D object; And If not transparent, reading a back-face of the 3D object and removing the back to determine a visible screen; and rendering based on second information constituting the visible screen; 3D graphics forming method for digital interactive broadcasting. delete The method of claim 1, further comprising selecting second information constituting the visible screen from the first information.  The method of claim 1, wherein the second information has a smaller amount of information than the first information. The method of claim 1, further comprising: generating first information including transparent information of the 3D object. Transmitting information constituting a three-dimensional object and a three-dimensional graphics forming method of any one of claims 1, 3 to 5 from the digital interactive broadcast transmitting device to the receiving terminal of the user. ; And And forming a three-dimensional graphic in accordance with the method in the receiving terminal. A recording medium having recorded thereon a three-dimensional graphic forming method for digital interactive broadcasting according to any one of claims 1 and 3. A modeling unit generating first information constituting the 3D object; It is determined whether the 3D object is transparent, and if it is transparent, the first information is supplied. If the 3D object is not transparent, the back screen of the 3D object is read and the back surface is removed to determine the visible screen. A filtering unit which supplies second information constituting the visible screen; And a rendering unit that renders the first information or the second information supplied from the filtering unit. The apparatus of claim 8, wherein the filtering unit comprises: a determination unit determining whether the 3D object is transparent; And And a controller for supplying the first information or the second information according to the determination unit. 10. The system of claim 8, wherein the 3D graphic forming system for digital interactive broadcasting comprises: a digital interactive broadcast transmitting apparatus; And a digital interactive broadcast receiving terminal. 3D graphic forming system for digital interactive broadcasting. The system of claim 10, wherein the digital interactive broadcast transmission device comprises the filtering unit. The system of claim 10, wherein the digital interactive broadcast receiving terminal comprises the filtering unit.

Images