Algebraic Smooth Occluding Contours

Contours, cusps and intersections Final contours Projectively transformed mesh Piecewise-Quadratic Surface Figure 1: Our method takes a triangle mesh, and renders smooth occluding contours for a given camera viewpoint. For each view, the algorithm produces a piecewise-quadratic surface, for which we show the occluding contours can be computed algebraically under orthographic projection. We use a projective transformation of the input mesh to handle perspective projection. By precomputing a conformal parameterization and a mapping from the viewpoint to the quadratic coefficients, contours and visibility can be computed very efficiently, in contrast to previous methods that used expensive heuristics or computations to produce smooth contours with accurate visibility. (Public domain Spot model by Keenan Crane.