ConTesse: Accurate Occluding Contours for Subdivision Surfaces

This article proposes a method for computing the visible occluding contours of subdivision surfaces. The article first introduces new theory for contour visibility of smooth surfaces. Necessary and sufficient conditions are introduced for when a sampled occluding contour is valid, that is, when it may be assigned consistent visibility. Previous methods do not guarantee these conditions, which helps explain why smooth contour visibility has been such a challenging problem in the past. The article then proposes an algorithm that, given a subdivision surface, finds sampled contours satisfying these conditions, and then generates a new triangle mesh matching the given occluding contours. The contours of the output triangle mesh may then be rendered with standard non-photorealistic rendering algorithms, using the mesh for visibility computation. The method can be applied to any triangle mesh, by treating it as the base mesh of a subdivision surface.

Automated summary

This article proposes a method for computing the visible occluding contours of subdivision surfaces by introducing new theory for contour visibility of smooth surfaces and necessary and sufficient conditions for valid sampled occluding contours. It also presents an algorithm to find sampled contours satisfying these conditions and generate a new triangle mesh matching the occluding contours. The method can be applied to any triangle mesh by treating it as the base mesh of a subdivision surface.