Curve and skeleton based shape deformations to support product design

In this paper an intuitive curve and skeleton based approach for product modelling is presented. Morphing-like deformations have been developed to allow for the evaluation of a larger set of alternative shapes compared to the set of shapes enerated by the current modelling tools. The method helps designers to search in the product domain for alternative shapes in a straightforward way and eliminates the work-arounds. Through a slide-bar control, these alternative shapes are generated by the transformation of an initial shape into the target one by means of a suitable skeleton extraction transparent to the user. The initial shape is abstracted by the skeleton and a distance function from the skeleton to the surface. For the target surfaces two categories have been considered, namely revolution-like and sweep-like surfaces. They are both defined through curves: an axis or a path and a profile. For the target surface, the user has to specify only the profile curve, as the axis or the path is represented by the skeletal curve extracted from the initial surface. The distribution of the morphing-like deformation is computed based on the skeletal curve, a distance function and the profile curve selected by the designer. The use of the skeleton guarantee the generated shapes belong to specific product domains and are therefore context-dependent.