COMPRESSION AND EXPANSION OF THREE-DIMENSIONAL GEOMETRIC DATA REPRESENTING REGULARLY TILED SURFACE PART OF GRAPHICAL OBJECT

摘要

PROBLEM TO BE SOLVED: To compress 3D geometric data corresponding to a regularly tiled surface part by using an encoded range value and an encoded vertex parameter value as compressed representation of 3D geometric data. SOLUTION: The 3D geometric data are tiled first (210). The regularly tiled surface part is selected and represented in compressed format (220) and that called a 'vertex raster'. Then the range of the vertex raster is specified in an encoded data stream (230). Then initial values of selected parameters are specified for the vertexes of the surface part represented with the vertex raster (240). Then the delta values of the selected parameters are set and how those parameters vary along the surface part represented with the vertex raster is shown (250). Then data in arbitrarily selected vertex units are specified as to the vertexes of the surface part represented with the vertex raster (260).