On Coherent Rotation Angles for As-Rigid-As-Possible Shape Interpolation

Abstract

Morphing algorithms, attempting to construct visually pleasing interpolations between shapes, have numerous applications in computer graphics. One of the desirable properties of such interpolations is avoidance of self-intersections in the deforming shapes. A local variant of this property precludes the triangles from becoming degenerate. We discuss a topological invariant of such non-degenerating morphs in the plane and discuss a simple improvement of the as rigid as possible shape interpolation algorithm that it motivates.