KR20080018405A - Computer-readable recording medium for recording of 3d terrain production program - Google Patents

Abstract

A computer readable recording medium for recording a 3D terrain production program is provided to enhance productivity in developing games by reducing works overlapped among game developing companies for using the 3D terrain. A computer readable recording medium comprises a terrain production module(110), an LOD(Level Of Detail) module(120), a texture module(130) and an XML parsing module(140). The terrain production module(110) sets the number and the size of tiles forming the 3D terrain and inputs a height value at a terrain of a range selected by a user. The LOD module(120) includes a precompiled mesh LOD function and an ROAM(Real Time Optimally Adapting Meshes) function wherein the precompiled mesh LOD function provides selective utilization of the 3D terrain differently modeled according to a distance and the ROAM function provides one map or multi-texturing by producing detailed meshes for each proper level. The LOD module(120) adjusts mesh precision degree of the 3D terrain step by step by The texture module(130) includes a splat texture function and a frame buffer mixing function wherein the splat texture function provides mixture among nonlinear textures for the 3D terrain by using independent tiling textures and the frame buffer mixing function provides rendering of each polygon for mixture of textures. The texture module(130) arranges a set tile for making the set tile have continuity with an adjacent tile in case of converting a tile into one among set tiles which have different shapes according to the kind of terrain. The XML parsing module(140) parses the 3D terrain at an XML template parser and outputs the parsed terrain in an XML format.

Description

Computer-Readable Recording Medium for Recording of 3D Terrain Production Program

1 is a view showing simply the internal structure of the terrain production program according to an embodiment of the present invention,

2 is a diagram illustrating a main body index buffer according to a preferred embodiment of the present invention;

3 is a view illustrating a connection between two tiles having different levels of detail by using a connection index buffer according to a preferred embodiment of the present invention;

4A to 4D are diagrams illustrating a process of applying a quadrant tree to tiles to render an object in a three-dimensional terrain generated according to a preferred embodiment of the present invention.

5 is a view showing a camera view frustum in a plan view of a three-dimensional terrain according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: terrain maker 110: terrain generation module

120: LOD module 130: texture module

140: XML parsing module

The present invention relates to a computer readable recording medium having recorded thereon a terrain production program that provides for the production of three-dimensional terrain. More specifically, the quad-tree and height maps are used to generate map tiles, and to adjust the precision of the mesh data, the precompiled mesh types LOD (Level of Detail) and Real-time Optimally Adapting (ROAM). Meshes), and a terrain creation program that outputs a three-dimensional terrain created by mapping textures using tile texturing, splatting textures, and frame buffer blends to a file in Extended Markup Language (XML) format. will be.

An online game is a game that a user connects to a server provided by a game manufacturer using a desktop computer, a notebook computer, or a mobile communication terminal. Examples of the online game include Blizzard's World of Warcraft and StarCraft. Of course, StarCraft can be used by users without being online, but World of Warcraft can only use the game by connecting to a server provided by the game manufacturer.

Currently, various multi-player role playing games (MMORPGs) are being developed in Korea. Most MMORPGs create games using terrain in open space.

The terrain in these games is the space in which a character or something is represented. Objects such as water, trees, rocks, etc. are placed on the floor and represent natural phenomena such as rain, wind, snow, etc. Generally, in game development, terrain constitutes the height of the floor and collides with the placement of characters or objects. Has the function of processing, spatial detection for fast rendering.

The terrain is divided into Out Door and In Door, and the outer terrain is mainly used in online games, and the inner terrain is mainly used in blocked places such as first person FPS (First Person Shooting) games.

On the other hand, the implementation of the external terrain should take into account several factors such as how to implement the height of the terrain, how to manage the wide terrain structure, how to implement the movement between the terrain, how to represent the smooth terrain, how the texture mapping of the floor, etc. Therefore, in order to express various heights and curves of the terrain, it provides a user interface for making it easier and faster, and in order to easily apply the texture of the terrain, such as the terrain mesh, each game developer has made their own. I am using the Level Editor.

However, each game developer can create, modify, delete, and save terrain files created using their own level editor. Therefore, common tasks between game developers can be duplicated. There was a problem to be performed.

In order to solve this problem, the present invention generates a map tile using a quad tree and a height map, and in order to adjust the precision of mesh data, a precompiled mesh type LOD (Level of Detail) and ROAM ( It uses Real-time Optimally Adapting Meshes and outputs three-dimensional terrain created by mapping textures using tile texturing, splatting textures, and frame buffer blends to XML (Extended Markup Language) format files. The purpose is to provide a terrain production program.

In order to achieve this object, according to the first object of the present invention, in a recording medium for recording a terrain production program for generating three-dimensional terrain, the program is the number of tiles constituting the three-dimensional terrain according to the user's input A terrain generation module configured to set a size of the tile and input a height value to a three-dimensional terrain of a range selected by the user; Precompiled Mesh Type LOD, which provides selective use of three-dimensional terrain modeled differently according to distance, and one-map or multi-texturing by creating detail meshes at appropriate levels. LOD module for adjusting the mesh precision of the three-dimensional terrain step by step including a Real-Time Optimally Adapting Meshes (ROAM) function to provide a; The Splatting Texture feature, which provides nonlinear inter-texture blending on three-dimensional terrain using independent tiling textures, and the rendering of each polygon for inter-texture blending within the frame buffer of the graphics card. It includes frame buffer blending, and sets set tiles to have continuity with adjacent tiles when the tiles constituting the 3D terrain are changed to any set tiles of the tile sets that have different shapes for each type of terrain. Texture module; And an XML parsing module for parsing the 3D terrain in an XML template parser and outputting the 3D terrain in XML format. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a view simply showing the internal structure of a terrain production program according to a preferred embodiment of the present invention.

The terrain production program 100 according to the preferred embodiment of the present invention includes a terrain generation module 110, a level of detail (LOD) module 120, a texture module 130, and an XML parsing module (Extended Markup Language Phasing). Module 140).

The terrain generation module 110 according to the preferred embodiment of the present invention sets the tile number and the size of the tile to be generated according to the user's input, and inputs a height value to the terrain in the range selected by the user. .

In order to create a terrain, the number of tiles and the size of tiles vary according to the precision of the terrain to be created. Therefore, the terrain with no height value is set by setting the number of tiles and the size of the tiles according to the precision of the terrain to be created. And change the height of the base terrain by entering a height value in the range selected by the user in the base terrain.

The basic terrain consists of a plurality of tiles, each tile comprising tile map index data, height field data, and quad tree structure data.

The map index data stores the tile position in the basic terrain, the height field data stores the height values entered at each coordinate in the tile, and the quadrant tree structure data contains the objects within the tile to render the objects ( In case of rendering, the structure data for applying the quadrant tree to the tiles is stored. In the present invention, a method of applying a quadrant tree to tiles to render an object will be described in detail with reference to FIG. 4.

The terrain generation module 110 stores a z value at each (x, y) position for a two-dimensional array of height values arranged in a regular grid for each tile of the base terrain, each of which is a z value. This is the height of the terrain at position (xy) of.

The terrain generation module 110 provides a center height shift function that sets the height of each tile of the basic terrain to be constant, and then increases or decreases the z value in order to create a random terrain. Divide by to adjust the height at each corner.

For example, set all z values for each tile in the base terrain to 0, set a range of z values to raise or lower the terrain to (-128, +128), and then set the z for each tile based on user input. You can set the height of each tile by increasing or decreasing the value within the range -128 to +128.

The LOD module 120 according to the preferred embodiment of the present invention adjusts the mesh precision of the terrain step by step.

Precompiled Mesh Type LOD (Precompiled Mesh Type LOD) is used to selectively use 3D terrain modeled differently according to distance.

The precompiled mesh type LOD function is a method of selectively rendering modeling data in which the number of polygons differs depending on the distance between the camera and the object to be rendered, and has a small number of polygons when the distance from the camera is far. Use modeling data to speed up rendering by reducing the number of polygons used when actually rendered. If you have three-dimensional objects that will appear far away on the screen, you can use a model with less data to speed up rendering, and if you need to look closer to the screen, you can use high-quality data to increase realism.

In the present invention, a polygon is a polygon that is the smallest unit used to express a three-dimensional shape in a three-dimensional terrain, and is a polyline connected with a start point and an end point by a line in three-dimensional space to express a curve by straightening a few points on the curve. It is used to indicate the edge of an object.

Therefore, when modeling three-dimensional terrain, by adjusting the polygon number in consideration of the position from the camera, a faster processing speed can be obtained without degrading the image quality.

The precompiled mesh type LOD feature is very fast because it depends on the GPU (Graphic Processor Unit) and fine tunes the terrain in proportion to the capacity of the cache.

However, since the precompiled mesh type LOD function has a problem in popping effects and tile texturing, the LOD module 120 of the present invention uses a real-time optimized adapting meshes (ROAM) function together.

The ROAM feature creates detail meshes at appropriate levels and uses fast texturing with one-map or multi-texturing to solve the popping effects and tile texturing problems of the precompiled mesh type LOD feature.

The ROAM feature improves rendering performance by reducing the number of polygons in parts of the terrain that don't need to be drawn in detail, such as partly flat or far away from the camera. That is, in order to draw in detail the parts that need more polygons, such as the terrain close to the camera or the bend, the more polygons are rendered in the necessary part of the terrain, and the less polygons are rendered in the parts that are not needed.

The ROAM feature uses a procedural generation of terrain to smoothly transition between low and high detail areas, using a binary tree of triangular intersections to extract the actual terrain geometry from a given height field. Make it up

The ROAM function creates an index buffer that covers the rendering template for each tile vertex. The index buffer defines how triangles are extracted from each tile, and controls the level of detail at which tiles are drawn. Since the index buffers of all tiles are stored in the same order, it is possible to exchange index buffers with each other.

For example, for a 9 * 9 grid, define the highest detail index buffers that apply to any 9 * 9 tiles, and for tiles with lower detail, skip some of the vertices that the index buffer points to. Just do it. The top index buffers draw 128 triangles using all 81 vertices, while the lowest level draws only one rectangle of a pair of triangles using only four vertices, with 32 triangle detail levels and There are eight levels of detail.

The ROAM function, which creates an index buffer and sets the level of detail, ensures that the triangles of the tiles interlock with each other without creating gaps, regardless of the difference in the level of detail of adjacent tiles, for seamless connection between tiles of different levels of detail. Creates a connection index buffer consisting of a body index buffer and a connection index buffer for use in linking tiles of different levels of detail.

The body index buffer represents the main part of the tile at a given level of detail and does not directly contact adjacent tiles. The joint index buffer, as its name implies, is designed to seamlessly connect adjacent tiles and prevent gaps when tiles at different levels of detail are connected.

2 is a diagram illustrating a main body index buffer according to a preferred embodiment of the present invention.

In the present invention, for the sake of understanding of the present invention, it is assumed that the tiles are connected to the low-level tiles by selecting their connection to the adjacent low-level tiles.

In FIG. 2 the white background portion of each body index buffer is replaced by a connection index buffer that can be seamlessly connected to the low level adjacent tiles. The connection index buffer is an index buffer smaller than the body index buffer, and replaces the edge portion of the body index buffer.

The joint index buffer consists of a number of triangles that can fit into adjacent tiles of low detail.

3 is a diagram for connecting two tiles having different levels of detail by using a connection index buffer according to a preferred embodiment of the present invention.

The 9 * 9 vertex tile has four levels of detail, so the number of index buffers required is 72, including 48 body index buffers and 24 connection index buffers. As the number of levels of detail increases, so does the number of index buffers, but the size of each index buffer is not large and memory can be wasted because it can be used repeatedly for the entire terrain.

For tiles with 9 * 9 vertices, there are four levels of detail and the highest level of detail must be connected to all three levels of detail, so three types of connections are required for each side of the highest level of detail.

As described above, since the ROAM function seamlessly connects the different levels of tiles using the body index buffer and the connection index buffer, the rendering code must be changed, and each tile and the adjacent tile must be examined for each tile.

In the present invention, since only the low level of detail is connected from the high level of detail, only the tiles having a lower level of detail than the adjacent tiles are examined, but in general, each tile adjacent to each tile is checked and the level of detail of the adjacent tile is checked. Select the connector index buffer of, and send the vertex of the connector index buffer along with the body index buffer to the rendering application program interface (API).

The texture module 130 according to the preferred embodiment of the present invention changes the tile of the basic terrain selected by the user to any one of a set of tiles having different shapes for each type of terrain.

The texture module 130 is arranged according to a predetermined rule so as to have continuity with adjacent tiles when the tile of the basic terrain is changed to any one of the tile sets having different shapes for each type of terrain.

In addition, the texture module 130 includes a splatting texture function so that non-linear blending of textures is performed on the terrain through high quality independent tiling textures. The texture module 130 is provided in the frame buffer of the graphics card. Supports frame buffer blending, which renders each polygon multiple times for blending textures.

The XML parsing module 140 according to the preferred embodiment of the present invention parses the 3D terrain generated by the user using the terrain creation program 100 by the XML template parser, thereby converting the 3D terrain into the XML format. To print.

The 3D terrain parsed by the XML parsing module 140 may be restored or used by a user.

The terrain production program 100 according to the preferred embodiment of the present invention includes a button for setting the tile size and the number of tiles of the newly generated terrain, a button for loading 3D terrain in XML format, an XML parsing module ( 140, it is preferable to provide a button for outputting and storing the terrain generated in XML format, a button for changing the height of the terrain, and a button for changing the texture of the terrain in a tool bar format. .

In addition, when a user clicks a button for changing the height of the terrain, a button for changing the texture of the terrain, and a button for changing the color of the terrain, it is preferable to activate or deactivate a panel corresponding to each button.

The panel for changing the height of the terrain according to the preferred embodiment of the present invention includes a button for increasing the height value of the terrain of the user selected portion in conjunction with the terrain generation module 110, a button for reducing the height of the terrain, the first terrain Button to transform the terrain to the same height as the height of the clicked part, to increase or decrease the height of the selected part with the mouse, and to reset the height of the terrain of the selected part, and the LOD In conjunction with the module 120, it is preferable to have a button for smoothly changing the height of the terrain of the selected portion.

In addition, the terrain production program 100 according to a preferred embodiment of the present invention may further include a button for changing the color of the terrain. A brush function may be provided to change the color of the terrain produced by interworking with the terrain generation module 110. The brush function may apply a color provided by the brush function to the area selected by the user. The brush function may not only change the color of the terrain but also change the texture of the terrain.

For example, if the basic terrain created using the terrain generation module 110 expresses the texture and the color of the soil by default, the user's selection is changed to the texture and color of the grass or marble using the brush function. .

4 is a diagram illustrating a process of applying a quadrant tree to tiles in order to render an object in a 3D terrain generated according to a preferred embodiment of the present invention.

The terrain used in online games is so large that it deals with large amounts of data, where you don't have to deal with all of the terrain, you need to use some sort of spatial segmentation to focus on the areas of interest and ignore other areas. In the present invention, the quadrant tree process is used.

It is worth noting that the above-described parts are objects that exist in the view frustum of the camera as shown in FIG. 5, and objects B and C exist in the camera's view frustum in FIG. 5.

In the present invention, it is assumed that the view frustum of the camera exists as shown in Fig. 4A when the tile of any one of the plurality of tiles is viewed from above, and it is assumed that the tile is composed of 256 cells. The quadrant tree process is used to exclude parts of the view frustum that are not included in the rendering.

The quadrant tree process repeatedly divides the entire tile into four pieces (hereinafter referred to as 'nodes') and divides each node into four nodes until each node has a specific size. At this time, the size of each node is divided to be the same.

With the first node (the tile in the present invention) as the top node, each node has a structure of four subnodes, and if the subnode becomes a certain size in the process of repeating the quadrant tree process, the quadrant tree process is terminated. In this case, the lowest node of the tree is called a leaf. Thus, the size of the cell is equal to the size of the leaf, which is the lowest node.

Assume that the camera's view frustum exists, as shown in Figure 2A. To render the portion of the camera's view frustum, whether the camera's view frustum exists in each sub-node during the quadrant tree process. Will be confirmed.

After performing the quadrant tree process once, check whether the camera's view frustum exists in each subnode, and perform the quadrant tree process only on the subnodes in which the camera's view frustum exists.

Figure 4B shows the quadrant tree process for a tile. After performing the quadrant tree process and verifying the existence of the view frustum for the subnodes A, B, C, and D, the view frustum does not exist for the subnodes of A, B, and C. The tree process is performed, and the result is shown as 4C.

Again, it is checked whether a view frustum exists for each of the sub nodes E, F, G, and H, and recognizes that the view frustum of the camera exists in H. In this case, 16 nodes, which are child nodes of the lower node H, may be checked for the existence of the view frustum, thereby obtaining a result for a cell in which the view frustum of the camera exists.

In order to apply the quadrant tree process to each tile as described above, the tile according to the preferred embodiment of the present invention includes quadrant tree structure data for performing the quadrant tree process.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

As described above, according to the present invention, by producing a three-dimensional terrain in the terrain production program and output in XML (Extended Markup Language) format, reducing the overlapping work between game developers who want to use the three-dimensional terrain productivity It is effective to improve.

Claims (4)

In the recording medium for recording a terrain production program for generating three-dimensional terrain, the program, A terrain generation module configured to set the number of tiles constituting the three-dimensional terrain and the size of the tile according to a user input, and input a height value to the terrain in the range selected by the user; Precompiled Mesh Type LOD (LOD), which provides selective use of the three-dimensional terrain modeled differently according to distance, and one-map or multi-texturing by creating detail meshes at appropriate levels. LOD module for adjusting the mesh precision of the three-dimensional terrain step by step including a Real-Time Optimally Adapting Meshes (ROAM) function to provide; Provides the rendering of individual polygons for blending between textures in the graphics card's frame buffer and the Splatting Texture function, which provides nonlinear inter-texture blending to the 3D terrain using independent tiling textures. And a frame buffer mixing function, wherein the set includes continuity with adjacent tiles when the tile constituting the three-dimensional terrain is changed to any one set of tile sets having different shapes for each type of terrain. A texture module for placing tiles; And XML parsing module for parsing the 3D terrain in an XML Marker Phaser (Extended Markup Language Templet Phaser) And a computer-readable recording medium having recorded thereon a program for generating three-dimensional terrain. The method of claim 1, wherein the tile, A computer-readable recording medium having recorded thereon a program for generating three-dimensional terrain, characterized in that it stores tile map index data, height field data, and quad tree structure data. The quadrant tree structure data of claim 2, wherein When rendering the 3D terrain using a scene management method, a program for generating a 3D terrain, wherein the quadrant tree structure of the tile for applying a quadrant tree process to the 3D terrain is stored. A computer readable recording medium having recorded thereon. According to claim 1, wherein the program, And a brush function for changing the texture and color of the three-dimensional terrain.

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