GPU-optimized indirect scalar displacement mapping

Abstract

Displacement mapping refers to a technique for rendering a high-frequency surface by adding geometric details encoded in a displacement map to a low-frequency base surface. This paper proposes a method for indirectly accessing the base surface using a special displacement map and then carrying out scalar displacement. Given a high-frequency triangle mesh, a coarse PN (point-normal) quad mesh is computed as the base surface. The parameters used to evaluate the base surface are precomputed such that scalar displacement from the evaluated points reaches the features of the original surface. The parameters are stored in the displacement map together with the displacement scalars. The run-time algorithm uses the hardware tessellation capability of GPU and reconstructs the high-frequency surface. Using the proposed method, surface features are accurately preserved, surface deformation is well supported, LOD control becomes quite flexible, and the base surface can be extremely simplified.