This paper introduces a fast continuous collision detection technique for polyhedral rigid bodies. As opposed to most collision detection techniques, the computation of the first contact time between two objects is inherently part of the algorithm. The method can thus robustly prevent objects interpenetrations or collisions misses, even when objects are thin or have large velocities. The method is valid for general objects (polygon soups), handles multiple moving objects and acyclic articulated bodies, and is efficient in low and high coherency situations. Moreover, the method can be used to speed up existent continuous collision detection methods for parametric or implicit rigid surfaces. The collision detection algorithms have been successfully coupled to a real-time dynamics simulator. Various experiments are conducted that show the method’s ability to produce high-quality interaction (precise objects positioning for example) between models up to tens of thousands of triangles, which couldn’t have been performed with previous continuous methods. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation- Virtual Reality 1.

In a prior paper, we described a haptic rendering algorithm for arbitrary polygonal models using a six degree-of-freedom haptic interface. In that paper, global search for local minimum distances provided repulsive forces between models. This paper augments that system with a local tracking algorithm that quickly updates and maintains globally computed minima. The global search continuously adds and deletes local minimum distance pairs being updated by the local search. This new system supports higher haptic interaction rates on more complex scenes than the previous approach.

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Abstract. This paper presents a volume-based haptic rendering method for a haptic shape modeling system based on simulated milling process. Previous proposals on point-based and ray-based haptic rendering methods cannot provide the force feedback in a milling process. The method proposed in this paper adopts a volumetric force model in material removal process. The force is calculated based on the relationship of material removal rate and machining power. Object and tool are both represented by Spatial Run-Length Encoding developed by the authors. Experiments on 5-axis milling process are carried out to determine the coefficients in the force model. 1

virtual prototyping

We present here the results obtained with the I-Touch framework in order to create a rigid bodies demonstrator with haptic feedback among multimodal feedback. Table of Contents

Abstract. We address the need of researchers in nanotechnology who desire an increased level of perceptualization of their simulation data by adding haptic feedback to existing multidimensional volumetric visualizations. Our approach uses volumetric data from simulation of an LED heteronanostructure, and it translates projected values of amplitude of an electromagnetic field into a force that is delivered interactively to the user. The user can vary the types of forces, and they are then applied to a haptic feedback device with three degrees of freedom. We describe our methods to simulate the heteronanostructure, volume rendering, and generating adequate forces for feedback. A thirty one subject study was performed. Users were asked toidentify keyareas of the heteronanostructure with only visualization, and then with visualization and the haptic device. Our results favor the usage of haptic devices as a complement to 3-D visualizations of the volumetric data. Test subjects responded that haptic feedback helped them to understand the data. Also, the shape of the structure was better recognized with the use of visuohaptic feedback than with visualization only. 1

This thesis describes the creation of an experimental platform for the exploration of human texture perception and its relationship to physical phenomena. Virtual textures are simulated and their physical and psychophysical properties are determined. Experiments were conducted into the ways in which modeling both texture and probe geometry influence the perception of virtual surfaces. The effects of compliance and friction on texture perception were also explored. Roughness detection thresholds were documented and their relationship to probe geometry and compliance were examined. A spectral analysis of the force signal demonstrated that force variability characterized roughness and that FA1 neural receptors were the receptors primarily responsible for mediating indirect roughness perception. Psychophysical studies of texture perception have been hampered by the need for the expensive manufacture of finely textured surfaces. These texture samples provide only discrete levels of experimental variables for study and are time-consuming to present to subjects. Virtual haptic textures provide continuous control of variables and are quick and easy to use. Unfortunately, psychophysical experimental results seem to differ between real and virtual textures. An algorithm was used which modeled probe and texture geometry to render virtual haptic