A Unified Framework for Haptic Interaction in Multimodal Virtual Environments.

In this paper we introduce a Modified Iterative Constraint Anticipation (MICA) method that provides a unified framework for direct and response-based indirect haptic interaction common in many interactive virtual environments. Collision constraints during response based interaction that are modeled using the linear complementarity problem (LCP) framework resolves collision constraints from response-based interactions while allowing for accurate computation of reaction forces. Direct user manipulation is enabled by the linear projection constraints (LPC). A smoothing filter is used to post-process the reaction forces arising from both LCP and LPC to achieve stable interactions in real-time. The effectiveness of MICA is demonstrated using example problems involving deformable bodies.