Volume animation using the skeleton tree

We describe a technique to animate volumes using a volumetric skeleton. The skeleton is computed from the actual volume, based on a reversible thinning procedure using the distance transform. Polygons are never computed, and the entire process remains in the volume domain. The skeletal points are connected and arranged in a "skeleton tree", which can be used for articulation in an animation program. The full volume object is regrown from the transformed skeletal points. Since the skeleton is an intuitive mechanism for animation, the animator deforms the skeleton and causes corresponding deformations in the volume object. The volumetric skeleton can also be used for volume morphing, automatic path navigation, volume smoothing and compression/decimation.