Haptic Rendering Techniques Supporting Material Removal

The term haptic refers to the tactile sensation perceived by the user when he is manipulating objects in a Virtual Environment. These sensations are extremely important in Virtual Reality simulators for training medical and dental procedures with the goal of increasing the level of motor skills. Many tasks trained, such as teeth and bones drilling, are held in rigid bodies and require parts of the virtual models to be removed. One way to manipulate these objects is by using voxel-based models, which divide the object into smaller parts that can be removed by the haptic device. This paper deals with a new method for haptic rendering with voxel-based rigid bodies that may be composed of various materials with different densities. The method describes the process for obtaining and storing the virtual objects, in addition to detailing the techniques used for collision detection, calculating the force feedback and removing parts of objects during the drilling process. The paper ends with an experiment that shows that the method provides stability and allows the haptic device to simulate the removal of voxels and also different material densities properly.