Vyatkin S.I. Photorealistic visualization of terrain based on the shape texture using graphics processing units

Abstract: The object of research is a new way of defining and visualizing a photorealistic terrain. The method to render a terrain as easily as a texture is proposed. A terrain model is coded as differential height map, i.e. the carrier surface is defined by algebraic means and only deviation from this basic surface is stored in the each node. Such a modeling method simplifies creation of smooth detail levels and shading. The data of height grid is not a subject to geometry transformations as the triangle vertices are. The geometry transformations are only required for the carrier surface. During the recursive voxel subdivision on each level, we project the centers of the voxels onto basic plane. The computed coordinates, as well as in the case of ordinary RGB texture map, will define address in the so called "altitude map" or "shape texture". The altitude corresponding to this address and a level of details is calculated, and are used to modify coefficients of the base plane equation. As a result will be obtained a surface modulated with the values from the altitude map. Visualization in real time on graphical accelerators is implemented. The method is based on the analytic geometry in space, differential geometry and vector algebra, interpolation theory and matrix theory, based on mathematical modeling and computer science. The main conclusions of the study are: the ability to generate the terrain using the same mechanism as for the texture color to display the terrain and changing levels of detail. The image interpolation is used for filtering heights dynamically similar to color texture. In comparison with the known methods the proposed method computation time substantially does not dependent on the resolution of the height map when generating a terrain.

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