Parameter-driven freeform deformations

Abstract

High-level parameters offer user an easy and intuitive tool to modify an existing model. In this paper, an approach of deforming freeform shapes using intrinsic parameters is proposed, where those parameters were not part of the model. Instead the parameters are introduced by user at the time he/she needs them. To achieve this, different from existing freeform deformation methods, a deformable template defined by intrinsic parameters is used as the bridge to link the original freeform shape and the user actions. Those templates can be defined by the user or simply derived from freeform feature concepts. With shape similarity analysis, a user-defined region of interest in the freeform shape is matched, or fitted, to a deformable shape template. By several different kinds of R3 to R3 functions, the region of interest is mapped to the fitted deformable shape template. Thus template parameters can be transferred to the original freeform shape. Through those quantitative intrinsic parameters, the user can easily modify the freeform shape. Several simple implementations were conducted in order to verify the proposed method. It is also described how the proposed technique can be applied in practical shape modelling applications.