Efficient Perspective-Accurate Silhouette Computation

Silhouettes are perceptually and geometrically salient features of geometric models. Hence a number of graphics and visualization applications need to nd them to aid further processing. The ecient computation of silhouettes, especially in the context of perspective projection, is known to be dicult. This paper presents a novel ecient and practical algorithm to compute silhouettes from a sequence of viewpoints under perspective projection. Parallel projection forms a special case of this algorithm. Our approach is based on the point-plane duality in three dimensions, that allows the ecient computation of the changes in the silhouette of a polygonal model between consecutive frames. We also present several applications of our technique to a variety of problems from computer graphics to medical visualization. We also provide experimental data that prove the eciency of our approach