METHOD FOR APPROXIMATING AND DISPLAYING THREE-DIMENSIONAL CAD DATA, AND SYSTEM FOR EXECUTING THAT METHOD

摘要

A method for approximating three-dimensional CAD data characterized in that the three-dimensional surface of CAD data is meshed-divided, the boundary ridgeline of that surface is subjected to polyline processing, a tangent vector is set at the boundary point of the polyline, interior points existing on the inside of a polyline are extracted among mesh-dicided lattice points, a polygon is formed by connecting the interior points each other or connecting the interior points with the boundary points, a Bezier curve is created on the polygon, a decision is made whether the Bezier curve falls within a specified error range from the surface of the CAD data or not, and mesh-dividing the three-dimensional surface again if it deviates from the error range.