3D Morphing Using Strain Field Interpolation

In this paper, we present a new technique based on strain fields to carry out 3D shape morphing for applications in computer graphics and related areas. Strain is an important geometric quantity used in mechanics to describe the deformation of objects. We apply it in a novel way to analyze and control deformation in morphing. Using position vector fields, the strain field relating source and target shapes can be obtained. By interpolating this strain field between zero and a final desired value we can obtain the position field for intermediate shapes. This method ensures that the 3D morphing process is smooth. Locally, volumes suffer minimal distortion, and no shape jittering or wobbling happens: other methods do not necessarily have these desirable properties. We also show how to control the method so that changes of shape (in particular, size changes) vary linearly with time.