Accurate and adaptive contact modeling for multi-rate multi-point haptic rendering of static and deformable environments.pdfVIP

Computers Graphics 57 (2016) 68–80 Contents lists available at ScienceDirect Computers Graphics journal homepage: /locate/cag Special Section on VRIPHYS 2015 Accurate and adaptive contact modeling for multi-rate multi-point haptic rendering of static and deformable environments Thomas C. Knott a,n, Torsten W. Kuhlen a,b a Visual Computing Institute, RWTH Aachen University, Germany b JARA – High-Performance Computing, Germany article info Article history: Received 18 December 2015 Received in revised form 17 March 2016 Accepted 21 March 2016 Available online 29 March 2016 Keywords: Haptic rendering Contact modeling Physics-based simulation Bimanual interaction abstract Common approaches for the haptic rendering of complex scenarios employ multi-rate simulation schemes. Here, the collision queries or the simulation of a complex deformable object are often performed asynchronously at a lower frequency, while some kind of intermediate contact representation is used to simulate interactions at the haptic rate. However, this can produce artifacts in the haptic rendering when the contact situation quickly changes and the intermediate representation is not able to re?ect the changes due to the lower update rate. We address this problem utilizing a novel contact model. It facilitates the creation of contact representations that are accurate for a large range of motions and multiple simulation time-steps. We handle problematic geometrically convex contact regions using a local convex decomposition and special constraints for convex areas. We combine our accurate contact model with an implicit temporal integration scheme to create an intermediate mechanical contact representation, which re?ects the dynamic behavior of the simulated objects. To maintain a haptic real time simulation, the size of the region modeled by the contact representation is automatically adapted to the complexity of the geometry in contact. Moreover, we propose a new iterative solving scheme for the inv