Morphing stick figures using optimized compatible triangulations

Abstract

A "stick figure" is a connected straight-line plane graph, sometimes called a "skeleton". Compatible stick figures are those with the same topological structure. We present a method for naturally morphing between two compatible stick figures in a manner that preserves compatibility throughout the morph. In particular, this guarantees that the intermediate shapes are also stick figures (e.g. they do not self-intersect). Our method generalizes existing algorithms for morphing compatible planar polygons using Steiner vertices, and improves the complexity of those algorithms by reducing the number of Steiner vertices used.