Anisotropic Sampling for Differential Point Rendering of Implicit Surfaces

International audienceIn this paper, we propose a solution to adapt the differential point rendering technique [KV01] to implicit surfaces. Differential point rendering was initially designed for parametric surfaces as a two-stage sampling process that strongly relies on an adjacency relationship for the samples which does not naturally exist for implicit surfaces. This fact made it particularly challenging to adapt the technique to implicit surfaces. To overcome this difficulty, we extended the particle sampling technique developed by Witkin and Heckbert [WH94] in order to locally account for the principal directions of curvatures of the implicit surface. The final result of our process is a curvature driven anisotropic sampling where each sample "rules" a rectangular or elliptical surrounding domain and is locally oriented according to the directions of maximal and minimal curvatures. Like in the differential point rendering technique, these samples can then be efficiently rendered using a specific shader on a programmable GPU