Collision Detection And Penetration Depth Calculation In Virtual Surgical Simulation

Abstract

Virtual Reality (VR) based surgical simulators create a simulated, realistic three dimensional surgical environments using advanced graphic and haptic rendering techniques. Virtual objects, which are geometric surface polygonal models of different human organs and instruments, are rendered in a common viewing volume. Such deformable or non-deformable polygonal models interact with each other. In order to provide a realistic response in real-time, detection of collisions in such models is the greatest challenge in the field of VR based simulators. Once collision is detected, the overlapping region and the largest penetration distance for a pair of intersecting objects need to be determined so that realistic deformations of the objects can be calculated and rendered. This thesis presents a simple and efficient algorithm to detect collisions between two objects and to calculate the penetration depth from the overlapping region. In a surgical simulator, there are two types of object pair interactions: deformable to non–deformable and, deformable to deformable object interactions. This work examines tissue to rigid body and, tissue to tissue interactions and provides realistic deformation to the interacting tissues in both cases.