A haptic sculpting technique based on volumetric representation

Abstract

We present a novel haptic sculpting technique where the user intuitively adds to and carves out material from a volumetric model using virtual sculpting tools in the similar way to handling real clay. Haptic rendering and model deformation are implemented based on volumetric implicit surface extracted from geometric model. We enhance previous volume-based haptic sculpting systems. Collision and force computation are implemented on an offset surface rather than the implicit surface to provide consistent contact sensation in both visual and haptic displays. In order to bridge the gap between fast haptic process (1 KHz) and much slower visual update frequency (30Hz), the system generates intermediate implicit surfaces between two consecutive physical models being deformed resulting in smooth force rendering. Magnetic surface established between an offset and the implicit surface is used to simulate a feeling of pulling in adding operation. The volumetric model being sculpted is visualized as a geometric model which is adaptively polygonized according to the surface complexity. We also introduce various visual effects for the real-time sculpting system including mesh-based solid texturing, painting, and embossing/engraving techniques. © Springer-Verlag 2004.