Morphing the BlobTree

Implicit surfaces have proved to be a particularly well suited and efficien t model for animating and morphing shapes of arbitrary topologies. The Blob Tree model is characterized as a hierarchical combination of skeletal primi tives organized in a tree. The nodes hold blending, boolean and warping ope rators, which allows the design of complex objects. In this paper, we address the metamorphosis of the BlobTree. This appeals a difficult task as the tree data-structures of the initial and final shapes ale completely different in the general case, and consequently cannot be m atched easily. We propose an original technique that solves the corresponde nce process and creates an intermediate generic BlobTree model whose instan ces interpolate the initial and final shapes. The animator may control the correspondence between features and can specif y both the speed of transformation and the trajectory of the nodes and the leaves of the generic BlobTree model. This provides the end user with a tig ht control over the transformation so as to achieve good visual effects.