This paper describes an algorithm for automatically generating a control skeleton for use in animating a polygonal data model. The algorithm has several steps. First, the figure is voxelized, and a Euclidean distance map is computed for voxels interior to the figure. A path creation algorithm then generates a tree-structured set of voxel paths spanning the object's interior. Simplification of these paths leads to a control skeleton for the object. The voxelization is used again to anchor the vertices of the polygonal model to the skeleton. Afterwards, new joint angles may be specified for the skeleton, and once the skeleton has been updated, vertices of the model can be repositioned accordingly. Unlike previous methods, the algorithm is fully automated, requiring very little user input. In addition, it can be applied successfully to a wide variety of objects. Furthermore, the algorithm is fast - it can produce a useful control skeleton for most objects in less than two minutes on a low-end PC.