Circular Interpolation for Morphing 3D Facial Animations
In this paper, we present a novel shape interpolation method that gives very good results for mesh morphing 3D facial animations. Our method interpolates vertices using circle arcs, thus generating, in a preprocessing algorithm, a specific circle center in 3D cartesian space for each pair of vertices. The arc is more or less accentuated, depending on the coordinates which the algorithm chooses for the circle center. These are calculated depending on the relation between the two vertex normals that correspond to the initial vertex and target vertex, and thereby a novel vertex normal weighting method is presented. The efficiency of our algorithm was tested on several facial animation examples with most dissimilar geometries and with very different features, and the results verify the fact that our method gives undoubtedly better results than linear interpolation does, avoiding the undesired and unnatural shrinkage problem which occurs in the latter case. Moreover, our method strikes significantly better computational costs as compared to other non-linear shape interpolation methods developed so far, which is a major advantage.
circular interpolation morphing 3d facial animations vertex normals blend shapes