Adapting Splat-based Models to Curved Sharp Features

Abstract

Splat-based models are good representations because they do not rely on topological information, thereby making complex modeling operations easier, while keeping the same approximation ratio delivered by triangular meshes. However, splat-based models are problematic when dealing with edges and corners, because, near those sharp features, splats need to be properly clipped in order not to show noticeable artifacts. In this article, we present a robust method for clipping splats near sharp features even in situations when the splats’ sampling rates are different on both sides of the sharp feature. Our method clips the splats by a bidimensional rational Bézier curve. The simple and uniform data used to define the clipping curve makes our method suitable for GPU implementation. We designed and implemented an automatic computation of the clipping curves and a pipeline for sampling a generic surface with splats and rendering it. In addition, we implemented a nonplanar elliptical splat, as an imprint in a cylindrical surface, in order to better approximate curved ridge lines and minimize the gaps that are unavoidable when dealing with planar splats only. Our curved splat requires only one additional parameter for rendering on the GPU. We demonstrate that our method, with the addition of curved splats, improves the rendering quality near curved sharp features and delivers good rendering speed.