Data preparation on polygonal basis

Converting NURBS based CAD Data into polygonal data often leads to unconnected faces at patch borders, wrong sided face normals and holes in the calculated mesh. Several methods are described in this paper to overcome these problems. The tesselation also results in a huge amount of polygons. To conquer such large data sets, different decimation algorithms are described and compared. All these tools are embedded in the Delphi viewer. Delphi provides an interactive environment including scientific visualization for decimation previewing, parameter distribution, and vertex classification, all superimposed on the data sets.