This is an (unfinished) algorithm for compressing mesh data to generate multiple level-of-detail meshes for different distances. It uses wavelets (the Haar basis in this case), and a hierarchical wavelet transformation technique. This algorithm differs from most modern wavelet-based approaches in its method of discretization: the model is divided up per-vertex using an evently-spaced KD-tree. Then, a one dimensional hierarchical version of a discrete wavelet transform coupled with a triangle collapsing scheme is used to generate the lower LOD meshes. This was mostly developed for an independent study with Prof. Martin Weinless during the Fall 2008 semester at the DigiPen Institute of Technology.
The lower resolution model (on the right) is 1996 triangles, while the original is 4416 triangles.