Ray Tracing Npr-Style Feature Lines

ABSTRACTWe present an algorithm for rendering high-quality line primitives of controllable on-screen width within a ray tracing framework, which can render simple NPR-style feature lines, including silhouette edges, crease lines, and primitive intersection lines. The algorithm is based on a variant of cone tracing, which measures distances in screen space and is used to detect and render feature lines. This technique opens ray tracing up to previously difficult or impossible styles of rendering, such as mesh visualization, as well as a variety of NPR techniques, such as apparent ridges.