REPRESENTATION OF 3-DIMENSIONAL SURFACE-TOPOGRAPHY IN CAD-SYSTEMS ANDIMAGE-PROCESSING SOFTWARE

Adequate graphical representation of a measured machined surface for e valuation of its functional properties, is a well-known industrial pro blem. The use of profile curves has been the dominating technique in d isplaying the roughness and topography of a machined surface. The repr esentation of topography is often made by assembling multiple-sampled 2-D profile curves (raster scan) to create the visual effect of a surf ace from a pre-selected viewing angle. During recent years, a number o f 3-D surface measurement systems have been presented and commercial s ystems are now available on the market. This paper describes the possi bilities with a system recently developed for representation of measur ed 3-D surface topography as wire frame or true surfaces. The system c onsists of a PC-computer for surface topography measuring and collecti ng of surface point coordinates connected to widespread CAD-systems an d image processing software, CATIA, AutoCAD and Image, which are runni ng on different computer platforms such as IBM-mainframe, Unix and VMS workstations as well as Apple Macintosh and IBM personal computers. S ome of the advantages and limitations of the system and areas of appli cation are demonstrated in a representation of bearing area and oil re taining volume of a cylinder liner.