Free-form deformation with weighted T-spline

A new method of free-form deformation, w-TFFD, is proposed, for which an original shape is deformed using weighted T-spline volumes. We generalize T-splines to weighted T-spline volumes that also permit T-junctions. Weighted T-spline volumes are a natural generalization of NURBS volumes but permit more flexible control lattices. Thus, w-TFFD holds many virtues of traditional FFDs and is more adaptive to objects with arbitrary topology or complex shape. The lattices can be automatically generated and approximate the shape of the object arbitrarily close by octree subdivision. Besides constructing and deforming a multiresolution lattice, users can also sculpt specific local details to their required shape by modifying weights. A set of direct-acting tools that are similar to previously proposed techniques can be applied to w-TFFD.