Virtual clay modeling using the ISU exoskeleton

A deformable non-uniform rational B-spline (NURBS) based volume is programmed for the Iowa State University (ISU) force-reflecting exoskeleton haptic device. A direct free-form deformation (DFFD) technique is applied for realistic manipulation. In order to implement real-time deformation, a nodal mapping technique is used to connect points on the virtual object with the NURBS volume. This geometric modeling technique is ideally incorporated with the force-reflecting haptic device as a virtual interface. The results presented in this paper introduce details for the complete set-up for a realistic virtual clay modeling task with force feedback. The ISU force-reflecting exoskeleton, coupled with a supporting PUMA 560 manipulator and the virtual clay model are integrated with the WorldToolKit (WTK) graphics display, and the results show that the force feedback from the realistic physically-based virtual environment can greatly enhance the sense of immersion.