Very early work on Mesh Decimation. Patch resulting holes by local retriangulation. Primarily developed for processing output of Marching Cubes. Mesh Optimization paper. Vertices connected by an edge are collapsed into a single representative vertex.
Efficiency depends on the error metric employed.
Distribute entirely new set of vertices over the surface of the model. Best suited to curved surfaces, bad for models with sharp corners and edges. Points are placed by point repulsion and then connected together. Very good results, but not very fast. The following section contains two case studies.