Real Time Rendering of Deformable Parametric Free-Form Surfaces

Frederick W. B. Li , Rynson W. H. Lau
Department of Computer Science
City University of Hong Kong
Kowloon
Hong Kong 

Deformable objects are required to improve the realism of virtual reality applications. They are particularly useful in modeling clothes, facial expression and human or animal charaters. A common method to render these objects is by polygonization. However, the polygonization process is computationally very expensive. If the object deforms, we need to execute this process in every frame to reflect the geometric change of the object. This limitation makes real-time rendering of deforming objects very difficult. Consequently, deformable objects are seldom incorporated in existing virtual reality systems. In this paper, we present an incremental method for rendering deformable objects modeled by parametric free-form surfaces. Two new frame coherence techniques are also introduced for crack prevention and parameter caching. Finally, we present a single hierarchical data structure which provides a multi-resolution representation of the object model.