Freeform surface modelling

Freeform surface modelling is the art of engineering Freeform Surfaces with a CAD or CAID system. The techniques used encompasses two main fields. Either creating aesthetic surfaces that also perform a function, for example car bodies and consumer products’ outer form, or technical surfaces for components such as gas turbine blades and other fluid dynamic engineering components. CAD software packages use two basic methods for the creation of surfaces. The first is from construction curves from which the 3D surface is then swept, lofted or meshed through. The second method is direct creation of the surface then manipulation of the surface poles/control points. When defining a form an important factor is the continuity between surfaces. How smooth they connect to one another. The continuity is defined using the terms G0 – position (touching) G1 – tangent (angle) G2 – curvature (radius) G3 – acceleration (rate of change of curvature)