We present a generalized method for free-form deformations that combines th e traditional free-form deformation model with techniques of scattered data interpolation based on Delaunay and Dirichlet/Voronoi diagrams. This technique offers many advantages over trad itional FFDs, including simple control of local deformations. It also keeps all the capabilities of FFD extensions, such as extended free-form deformations and direct FFDs. The deformation model has much potential for 3D modeling and animation. We choose to illustrate this with a non-trivial hum an simulation task: hand animation. We implement a multi-layer deformation model where DFFDs are use d to simulate the intermediate layer between the skeleton and the skin.