In haptic simulations a human operator is coupled to a virtual environment, in such a way that the user is able to perceive the scene with his/her sense of touch. In Figure 1 the interaction paths between user and virtual world are shown. To obtain a good level of immersion, at least two interaction paths must be provided for haptic simulations, namely the visual and the haptic path. In the upper part the visual path is shown, in which a visual rendering algorithm computes images from a virtual model. These images are displayed to the user by a visual display. The user can modify the viewpoint by moving the virtual camera, e.g., by using a spacemouse or, if a tracking system is used by moving his/her head. The lower part presents the haptic path, which is in focus of the present book. Similar to the visual path, this path contains a software and hardware module, i.e., a haptic rendering algorithm and a haptic interface.