Surfaces for irregular regions

Surface modelling is an accepted part of CADCAM, and there is a wide range of systems offering the facility. The mathematics underlying the surfaces tends to differ from system to system, but there is an overall similarity in that most surfaces are based on a rectangular parametric grid. While this is the most practical way of creating surfaces for general use it makes them intrinsically unsuited to certain commonly occurring types of geometrical configuration. This article describes a collaborative venture between CADCentre Ltd. and Loughborough University which has produced a new type of surface to cope with these irregular geometries.