The level set method can implement a wide variety of shape modeling operations (e.g. offsetting, skeletonization, morphing, blending, smoothing, sharpening, embossing, denoising, sculpting, growing, texturing and fitting) simply by specifying a corresponding speed function that controls the growth of an evolving voxel isosurface. The problem is that the basic level set method is implemented on a fixed resolution grid, which limits the utility of these shape modeling operations. We instead represent surfaces with a collection of radial basis function dipole pairs, and derive the motion of these dipoles to implement a surface propagation similar to the level set method but on a smooth, arbitrary resolution model. We demonstrate the utility of this approach with new level set methods for surface fitting, blending and center redistribution for RBF dipole models.

Morse theory reveals the topological structure of a shape based on the critical points of a real function over the shape. A poor choice of this real function can lead to a complex configuration of an unnecessarily high number of critical points. This paper solves a relaxed form of Laplace's equation to find a "fair" Morse function with a user-controlled number and configuration of critical points. When the number is minimal, the resulting Morse complex cuts the shape into a disk. Specifying additional critical points at surface features yields a base domain that better represents the geometry and shares the same topology as the original mesh, and can also cluster a mesh into approximately developable patches. We make Morse theory on meshes more robust with teflon saddles and flat edge collapses, and devise a new "intermediate value propagation" multigrid solver for finding fair Morse functions that runs in provably linear time.