Improving G1 surface joins by using a composite patch

摘要

ar approach to joining surface patches smoothly across a given boundary curve is to choose the transversal derivative as an average of the tangents at the end points. However, it can be observed that this type of rational linear reparametrization forces the center transversal derivatives outside the convex hull of the remaining boundary derivatives unless certain tangent ratios are equal. The result are undesirable features in the surface. To circumvent the problem a composite patch is introduced. It consists of tensor-product patches that separate the original boundary tangents, so that constant G$+1$ joins can be used.