US Patent 9064311 Method for compressing/decompressing a three-dimensional mesh

The method for encoding/decoding three-dimensional meshes of dots or vertices connected in the form of facets delimited by edges; the mesh M is defined by connectivity data T and geometry data G includes the steps of:lossless encoding of the connectivity data T into encoded connectivity data Tc,iteratively generating a progressive mesh hierarchy, i.e. a set of meshes with progressive levels of detail, PM(M*),generating a piecewise smooth approximation M* of the original mesh M, from the mesh connectivity T; this smooth approximation M* being described as follows:a. compressed connectivity data Tc;b. a small number N of control dots andc. a number of indexes S of edges called protruding edges of the mesh M, identified beforehand,using the progressive mesh hierarchy PM(M*) to calculate a prediction of approximation errors in M* compared with the original mesh M.