Blend surfaces for set theoretic volume modelling systems

Most volume modelling systems are very limited in the complexity of the surfaces which they support. This is satisfactory for basic models of most mechanical components, since the functional surfaces are not usually complex. However, there are often blends between simple base surfaces. This paper presents a technique appropriate for blend definition and profile control. A discussion of blend conics is used to develop analogous surfaces for use in typical volume modelling systems. These surfaces are then used to set theoretically define bounded volumes for fillets and chamfers. Empirical results show that the method described suits many engineering applications.