The Multi-resolution 3D Visualization Of Large Terrain Based On Geometry Clipmap

With the wide use of digital science and the popularization of informatization, the importance of the 3D visualization of terrain becomes clearer. But the common PC memory capacity cannot contain massive geometric and texture data. To solve this problem and guarantee the efficiency of drawing, the Geometry Clipmap algorithm is adopted to draw the terrain. In order to make the best of GPU to promote the efficiency of drawing, this paper obtains each vertex elevation values through vertex textures. Meanwhile, this paper simplifies the organization method of triangle strips. Using simple frustum culling method and dynamically determine map layers to reduce the vertexes of drawing. Using simple and direct method eliminate cracks. Based on special structure of lay, this paper will come up with the new method(binary positioning method) of data updating to reduce each frame’s amount of data updating after the motion of viewpoint. Use the method of adding virtual layer to compensate for disadvantages of the Geometry Clipmap algorithm, so that the fine layer can expand the range of movement in the condition of limited terrain size and limited number of Geometry Clipmap layers. The experiment results show that this kind of algorithm can complete large‐scale terrain visualization rendering by using a little memory, and get a higher frame numbers, guarantee the realistic display of the terrain, roam smoothly, and realize real‐time 3D visualization of large–scale terrain.