Triangle mesh compression

摘要

A computer implemented method of processing elevation mesh data defining a polygon mesh surface to determine an alternative representation of the surface using fewer polygons than in the original representation is disclosed. Initially original elevation mesh data is sub- sampled to generate a low resolution representation of the polygon mesh surface where vertices of polygons correspond to points on a coarser X-Y grid than the original elevation mesh data. Error values indicative of the extent that portions of the surface defined by the low resolution elevation mesh data differ from corresponding portions of the surface defined by the original elevation mesh data are then determined. An alternative representation of the polygon mesh surface is then generated which comprises: low resolution elevation mesh data for the portions of the polygon mesh surface associated with error values less than a threshold value; transition mesh data defining a polygon mesh surface immediately adjacent the perimeter of portions of the surface represented by the low resolution elevation mesh data; and higher resolution elevation mesh data for the remaining portions of the polygon mesh surface.