G(1) CONTINUITY OF B-SPLINE SURFACE PATCHES IN REVERSE ENGINEERING

When a clay model or industrial part is reverse engineered, B-spline surfaces are typically fitted to surface data points collected by a coordinate measuring machine, or, in more recent times, a laser scanner. The surface fitting procedure results in a patchwork of B-spline surfaces. Some of these patches may be required to blend smoothly with their neighbours to a specified degree of continuity. Past research on surface patch continuity has focused on Bezier surfaces. In the paper, some of those techniques are modified and applied to B-spline surfaces. An optimization method is presented which can achieve an approximate global G(1) continuity of a given patchwork of B-spline surfaces. The method is illustrated by a complex physical model, which is digitized by a 3D laser scanner, and reverse engineered to create a smooth CAD model.