From Hand Sketches to Freeform CAD Surface Models

Abstract

The objective of this chapter is to present the use of 2D graphics (sketches, drawings, photographs, 2D documents) for the creation of 3D models. The application of 2D graphics is common and also immensely useful for reconstructing existing technical products, as well as for the development of new products in cooperation with industrial designers. This chapter also shows how to modify surfaces freely—creating freeform surfaces in order to achieve specific design effects. Although the free forming of surfaces is not related exclusively to surface modelling—planes, as well as solid bodies can be free formed, too—and for the reasons of presenting the procedure and the technological work clearly, free transformation is explained on a surface body in this case. In the example, shown here, a 2D designer sketch is used to create a lamp shade, i.e., a shell element that can be created most easily by means of surface modelling. This chapter also shows how to uniformly divide a continuous plane or surface into several separate surface segments, while preserving their geometric continuity. The suggested procedure can be used for different purposes in design and engineering, including modifying the visual surface properties of a product, or in order to set limited stress areas in numerical simulations.