Fitting and Manipulating Freeform Shapes Using Templates

Finding effective and efficient tools for complex freeform shape modification continues to be a challenging problem in computer graphics and computer-aided design. Although current approaches give reasonable results, their computation time and complexity often prevent their further development in more complex cases, especially in reusing an existing design. In this paper, for a better control of existing freeform shapes, deformable freeform feature templates are introduced. By the advantage of a small number of intrinsic parameters, a given freeform shape can be quickly approximated by one of the deformable templates. The deformable templates are further developed to track and match complex freeform shapes, resulting in extendable templates. With mappings, the original shape and the approximated template are associated. Thus, further shape manipulations can be conducted effectively using high-level intrinsic shape parameters. Experiments were carried out to verify the proposed algorithms. It is also described how the matching and manipulating techniques can be applied in computer graphics and computer-aided design applications.