Freeform modelling using sweep differential equation with haptic interface

摘要

This paper presents the development of a virtual sculpting system and addresses the issues of interactive freeform solid modelling with haptic interface. A virtual reality (VR) approach is taken to make the developed system more intuitive and interactive. The virtual sculpting method is based on the metaphor of carving a primitive or imported solid model into a 3D freeform object. The geometric modelling is based on the sweep differential equation method to compute the boundary of the tool swept volume. The ray-casting method is used to perform Boolean operations to simulate the sculpting process. A new method of surface reconstruction from dexel data is presented. The PHANToM manipulator is used to provide the position and orientation data of the sculpting tool and also to provide haptic sensation to the user hand during the sculpting. An accuracy analysis is performed to determine the limitations on the sculpted geometric details.