Chinese Journal of Computers   Full Text
Title	Velocity Driven Levels of Detail Haptic Rendering Algorithm for Complex Scenes
Authors	ZHOU Wan-Lin WANG Dang-Xiao ZHANG Yu-Ru WANG Yu
Address	(State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, Beijing 100191)
Year	2009
Issue	No.8(1560—1570)
Abstract &   Background	Abstract In haptic interaction technology, new challenges have been put forward on complex scene rendering. Based on the requirements of a dental training system, velocity driven levels of detail (LOD) haptic rendering algorithm for complex scenes is proposed. Firstly, a large amount of data is simplified with CATIA to realize level-of-detailed modeling for the teeth data. Secondly, based on analysis of the relationship between the perceptible features and the interaction velocity, velocity-driven LOD force rendering algorithm is proposed as switching criteria between discrete model levels. Thirdly, a surface contact point (SCP) mapping algorithm is developed to ensure the continuous change of virtual force signal at switch time between two successive LOD models, which ensures the stability of haptic rendering. Finally, three experiments based on planes, spheres and complex teeth model are carried out to validate the fidelity and stability of the proposed algorithm. The experiments results illustrate that the algorithm can stably render scenes with large numbers of triangles under various interaction velocities. Keywords virtual reality; haptic rendering; complex scene; LOD; velocity driven Background The paper discusses about haptic interaction technology, which is a special branch in virtual reality. Haptic interaction discusses how to improve the communication between human and computer, and the communication between human and robots through the sense of touch. Its application areas include: surgery simulation, entertainment, tele-robot, computer-aided-design and industrial design etc. Researchers in both computer graphics and interactive techniques have showed great interests in haptics. People mainly focus on haptic rendering algorithms for various geometric representations. In this paper, velocity driven levels of detail (LOD) haptic rendering algorithm for complex scenes is proposed. The project was sponsored by National Natural Science Foundation of China (60605027) and the National High Technology Research and Development Program (863 Program) of China (2007AA01Z310). The project is mainly about haptic technology and visual-haptic collocation system, which may be used in dental surgery simulation or virtual assembling. Human-machine Interaction Lab mainly focuses on haptic interaction. The goal is to discover and understand the mechanism of haptic in information communication, and to make creation and invention using the mechanism. The authors have developed haptic simulation systems including a dental surgery simulation prototype. However the virtual scenes of the dental surgery simulation system cannot be too complex because of the refresh rate of the haptic system. The result in this paper helps to increase the capacity of data sets.