• Journal of the Korea Computer Graphics Society
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• v.2 no.1
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• pp.68-76
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• 1996

One of the major problems in GIS(Geographical Information Systems) involves acquiring 3-D terrain data. Because conventional methods such as land surveying or analysis of aerial photographs are costly, the method of using existing paper maps has been gaining considerable attention. This method demands three processing steps: 1) extraction of contours, 2) assignment of height values to the extracted contours, 3) reconstruction of 3-D terrain data. In this paper we systematically develop a procedure for acquiring 3-D terrain data from contour solutions. For the first two steps, we describe the necessary operations and roughly sketch solutions. For the last step, we propose an efficient raster-based algorithm and present the results of experiments with existing paper map images.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.968-970
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• 1995

The Information Diffusion Neural Networks is proposed to regenerate the 3-dimensional terrain elevation data from contour lines. Contours in paper map are an expression of terrain elevation in highly compressed form. A real time regeneration of terrain data for each grid points from the the contour information is required for various applications. In the proposed neural networks, the elevation information on contours is diffused to neighbor units through updating its output toward that of neighbor units. An interpolation of terrain information is achieved from such computation mechanithm. Terrain data regeneration simulation has been done with sampled terrain data on contour lines.

• Journal of Institute of Convergence Technology
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• v.12 no.1
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• pp.1-5
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• 2022

This paper describes an algorithm for generating a terrain using a noise function and a height map as one of the procedural terrain generation methods. The polygon mesh data structure to represent the generated terrain concisely and render it is also described. The Perlin noise function is used as the noise technique for terrain mesh, and the height data of the terrain is generated by combining the four noise waves. In addition, the terrain height information can be also obtained from actual image data taken from the satellite. The algorithm presented in this paper generates the geometry part of the polygon topography from the height data obtained, and generated a material for texture mapping with two textures, that is, a diffuse texture and a normal texture. The validity of the terrain method proposed in this paper is verified through application examples, and its possibility can be confirmed through performance verification.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1538-1551
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• 2021

The current drone flight plan creation creates a flight path point of two-dimensional coordinates on the map and sets an arbitrary altitude value considering the altitude of the terrain and the possible flight altitude. If the created flight path is a simple terrain such as a mountain or field, or if the user is familiar with the terrain, setting the flight altitude will not be difficult. However, for drone flight in a city where buildings are dense, a safer and more precise flight path generation method is needed. In this study, using high-precision spatial information, we construct a drone safety flight map with a 3D grid map structure and propose a flight path search algorithm based on it. The safety of the flight path is checked through the virtual drone flight simulation extracted by searching for the flight path based on the 3D grid map created by setting weights on the properties of obstacles and terrain such as buildings.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.291-293
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• 2010

Terrestrial LiDAR can be used to accurately measure the 3D slope terrain because it can obtain the entire shape of the object, instead of only a specific location, while not much influenced by the environment, and it can create more dense and precise 3D coordinates than those of aerial LiDAR. Therefore, in this study, subject areas with different terrain conditions were selected, the terrestrial LiDAR device was used to observe the slope terrain, and a slope terrain analysis technique was proposed based on the observation results.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1483-1495
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• 2006

The navigation mesh represents a terrain as a set of triangles on which characters may move around. The navigation mesh cab be generated automatically, and it is more flexible in representing 3D surface. The number of triangles to represent a terrain may vary according to the structure of the terrain. As characters are moving around on a navigation mesh, the path planning can be performed more easily by projecting the 3D surfaces into 2D space. However, when the terrain is represented with an elaborated mesh of large number of triangles to achieve more realistic movements, the path finding can be very inefficient because there are too many states(triangles) to be searched. In this paper, we propose an efficient method of path finding in 3D games where the terrain is represented by navigation meshes. Our method uses the visibility tests. When the graph-based search is applied to elaborated polygonal meshes for detailed terrain representation, the path finding can be very inefficient because there are too many states(polygons) to be searched. In our method, we reduce the search space by using visibility tests so that the search can be fast even on the detailed terrain with large number of polygons. First we find the visible vertices of the obstacles, and define the heuristic function as the distance to the goal through those vertices. By doing that, the number of states that the graph-based search visits can be substantially reduced compared to the plane search with straight-line distance heuristic.

• Journal of the Korea Society for Simulation
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• v.6 no.1
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• pp.61-69
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• 1997

In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models are convenient way to get the data of terrain models, it is not easy to gain the final results by manipulating the data of terrain model. However, by using the object oriented programming techniques, we could reduce the effort of programming job to find the final result. In this paper, a set of classes made by object oriented programming technique is presented. To show the results, the data of a terrain model were made by a fractal technique, namely, the midpoint displacement methods with square lattices of points.

• Journal of Advanced Navigation Technology
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• v.5 no.2
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• pp.123-133
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• 2001

The existing visualization methods using the satellite images or map images require complicated preprocessing stages and a large amount of visual data to represent the 3-D terrain. This paper presents a 3-D visualization method for geographical information, which enables automatic generation of 3-D terrain. It is generated based, on contour information obtained from a numerical map. This paper also introduces a method that resolves the three main problems needed to visualize 3-D terrain from contour lines such as correspondence, tiling, and branching. The virtual contour line is defined to extend a distorted contour line to have a similar shape to the corresponding contour line that is used, to generate 3-D surfaces. It helps that 3-D terrain is represented exactly and in detail.

• Korean Journal of Remote Sensing
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• v.10 no.2
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• pp.121-132
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• 1994

A GIS based tactical terrain analysis system named ATTAS(Army Tactical Terrain Analysis Software) has been designed and implemented to support the field commanders for enhancing the capabiliy of their unit and efficiency of weapon system. This system is designed to provide computer graphics environment in which the analyst can interactively operate the entire analyzing process such as selecting the area of interest, performing analysis functions, simulating required battlefield operation and display the results. This system can be divided into three major sections; the terrain analysis modules, utilites, and graphic editor. The terrain analysis module inclused surface analysis, line of sight analysis, enemy disposition, 3D display, radar coverage, logistic route analysis, shortest path analysis, atmospheric phenomena prediction, automated IPB (Inteligence preparation of Battlefield), and other applied analysis. A combination of 2D and 3D computer graphics techniques using the X-window system with OSF/Motif in UNIX workstation was adopted as the user interface. The integration technique of remotely sensed images and GIS data such as precision registration, overlay, and on-line editing was developed and implemented. An efficient image and GIS data management technique was also developed and implemented using Oracle Database Management System.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.78-85
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• 2012

This paper proposes an efficient algorithm to develop a 3D terrain tools which is essential in the development of 3D computer games. In particular, this paper proposes a cross detection technique to improve picking speed. In other words, this paper proposes a more efficient cross detection technique consisting of a ray and a parallelogram than a cross detection technique consisting of a ray and a triangle. So, we can confirm the faster picking speed. This paper uses a picking example among DirectX SDK samples to test it. In addition, this paper compares the number of function calls for cross detection using the existing techniques and the proposed technique. As a result, in this paper the proposed technique has fallen off to about a 50 percent than the existing techniques. And if it is calculated by times, in this paper the proposed technique was reduced to 1 to 2 seconds than the existing techniques. Additionally, in this paper 3D terrain tools are provide more improved algorithms for features such as texture splatting, height map control, object arrangement and realistic water effect. So, 3D terrain tools is available efficient in the development of real 3d computer games.