Terrain visibility analysis method based on depth mapping

Terrain visibility analysis is widely used in many areas, but the existing methods still have some unsolved problems, such as complexity in computation and bad applicability. In this paper, a depth mapping based method is given to solve the problem. First, the terrain was rendered with perspective projection from the observation point, and the depth of the terrain surface was saved into a depth map as output; then, the terrain was rendered again with orthogonal projection from top view, and the depth map was mapping onto the terrain surface, and the visibility of the fragment was obtained by comparing its depth value in depth map's view projection coordinate and its depth mapping value. Results show: the new approach can efficiently yield visibility results of high accuracy; in addition, it is applicable for different terrain models even with objects on them, because the algorithm is independent of geometry.