Local Model of Interaction for Haptic Manipulation of Rigid Virtual Worlds

In this paper we propose a local model of rigid body interaction that provides users with convincing kinesthetic feedback while they manipulate a virtual tool within a rigid multibody virtual world. The virtual tool can be a rigid object or a linkage. The local model can interface a haptic device to any virtual environment simulation that provides the contact position, the contact normal direction, and the penetration depth of the virtual tool into the virtual world at the virtual tool contacts. The local model includes a proxy of the virtual tool that embeds an approximation of its geometry and of its dynamics, and that eliminates force discontinuities at model updates via proxy deformation. In addition, the model includes active and predicted virtual tool contacts. Predicted contacts are used to maintain force continuity and to better constrain users to tight virtual spaces. Experiments performed within a planar virtual world demonstrate that, compared to prior local models of rigid body interaction, the proposed model enables users to feel stiffer contacts and improves users' perception of free space in locally cluttered virtual environments.