Blendeforming: ray traceable localized foldover-free space deformation

Since the introduction of Free Form Deformation (FFD) by Sederberg and Parry (1986), a great deal of research has been performed in the area of space deformation for 3D shape modeling. However, many techniques do not provide local control, and almost all are non-unique mappings that are capable of producing foldover, making them unsuitable for use with implicit surfaces, or any object that should not self-intersect, and causing some problems for ray tracing. In this paper a new approach to deformation is presented. Blendeforming (Blended Deforming) provides foldover-free deformation with local control, which preserves implicit functions. Blendeformers are reversible deformations that are suitable for use in interactive modeling and ray tracing.