Study On Collision Detection Algorithms Of Laparoscope Simulation Surgery System

With the development of the technology in virtual reality, people are more and more thinking of the problem of collision detection, because the real-time and exact collision detection is very important to improve reality and enhance immersion for virtual environment. Virtual surgery is an important application of virtual reality technology in medicine. It can offer a platform enabling the surgeons to practice on virtual patients, thus getting rid of financial and ethical problems brought by training on living animals or on cadavers. In virtual surgery, it requires both the abilities to interact in real-time with the virtual organs through a force-feedback device and to perform a real-time visualization of the deformations. But collision detection is the precondition of calculating the deformation of the tissue; and to receive the presion deformation of the organs depending on the collision detection result. So collision detection is quite important in medical VR.On the basis of international and domestic references in the fields concerned, research on collision detection of virtual surgery is done in this paper, and its main works are included as follows:1. Based on the full research of inherent characters of k-DOPs hierarchical box. this thesis implements a series of key techniques such as building k-DOPs and k-DOPs tree, and overlap test between k-DOPs boxes, verifies the attribute that k-DOPs has the advantage that it is fit for the complex virtual surgery.2. An improved algorithm is utilized for the basic geometric elements overlap test, the experiment proves that the improved algorithm for overlap test is fast and better.3. By studying and utilizing temporal-spacial coherence in virtual environment in this paper, a traverse tracing strategy is proposed. The experiment result proves that it can reduce the intersection tests need to be computed between bounding volumes by tracing the traverse process in previous time to gain traverse path in current time. The correctness and validity of collision detection can be guaranteed by maintaining the trace list. 4. Collision detection between the two rigid bodies is simulated. It proves the performance of bounding box based on 14-DOPs is better than AABB.