Abstract-We present a novel physically-based approach for simulating realistic brittle fracture of impacting bodies in real-time. Our method is mainly composed of two novel parts: (1) a fracture initiation method based on modal analysis, (2) a fast energybased fracture propagation algorithm. We propose a way to compute the contact durations and the contact forces between stiff bodies to simulate the damped deformation wave that is responsible for fracture initiation. As a consequence, our method naturally takes into account the damping properties of the bodies as well as the contact properties to simulate the fracture. To obtain a complete fracture pipeline, we present an efficient way to generate the fragments and their geometric surfaces. These surfaces are sampled on the edges of the physical mesh, to visually represent the actual fracture surface computed. As shown in our results, the computation time performances and realism of our method are well-suited for physically-based interactive applications.

Abstract. In this paper we introduce the combined use of BrainComputer Interfaces (BCI) and Haptic interfaces. We propose to adapt haptic guides based on the mental activity measured by a BCI system. This novel approach is illustrated within a proof-of-concept system: haptic guides are toggled during a path-following task thanks to a mental workload index provided by a BCI. The aim of this system is to provide haptic assistance only when the user's brain activity reflects a high mental workload. A user study conducted with 8 participants shows that our proof-of-concept is operational and exploitable. Results show that activation of haptic guides occurs in the most difficult part of the pathfollowing task. Moreover it allows to increase task performance by 53% by activating assistance only 59% of the time. Taken together, these results suggest that BCI could be used to determine when the user needs assistance during haptic interaction and to enable haptic guides accordingly.