Morphing algorithms aim to construct visually pleasing interpolations (morphs) between 2D or 3D shapes. One of the desirable properties of a morph is avoiding selfintersections of the deforming shape. We investigate topological invariants (based on winding number) of planar morphs between compatible triangulations that do allow global self-intersections but avoid local ones. Equivalently, such morphs do not make any of the triangles degenerate. We discuss a variant of the as rigid as possible morphing algorithm based on these invariants that allows to handle cases when a large amount of twist is required to transform the source triangulation into the target triangulation. 1 Background Morphing is a well-established problem a number of researchers have been working on for many years. We limit ourselves to discussion of the results that apply to the same setting as assumed in this paper, namely morphing between compatible planar triangulations. Different variants of a method of deformi...