The hand-based virtual reality system with haptic force feedback is a new field in VR research. The research target of the thesis is provide the realistic visual and haptic feedback of the system at the minimal cost, and improve the system's real-time property. The main research of the thesis is about collision detection between virtual hand and objects, and simulation of deformable objects. The main work and contribution are following: 1. A hybrid bounding box OBB-AABB is presented for collision detection between hand and rigid objects. It takes the advantages of OBB and AABB, and makes a compromise between tightfitting property and simplicity. It is an effective approach to detect the collisions between the models that differ greatly in their complexities. 2. A collision detection method based on OBB-AABB is presented. It uses the improved Liang-Barsky clipping line algorithm to test the overlap between OBB and AABB. Compared with Separating Axis Theory algorithm, the clipping line algorithm is more simple. 3. Deformable object model is based on MAT (medial axis transform), and is represented by NURBS surface. The thesis presents a simple-performed method for single-point collision detection of the user's position with the deformable objects. It first uses the sphere bounding box to discard some unnecessary computation, then uses the medial axis surface to detect the collision. 4. Reposition 4 most influenced control points of the surface to modify the shape, when the user's position enters the deformable object. The NURBS interface in OpenGL API is used to display the surfaces. The performance is satisfactory. 5. Different methods are used to compute the haptic feedback of rigid objects and deformable objects. A given force is exerted on the user as the rigid object's haptic force feedback. Mass-spring model is used to compute the haptic force feedback of deformable objects. The experiments show that the user can get a realistic feeling. 6. A virtual reality system with haptic force feedback is conducted interfaced with CAS-Grasp. The algorithms above are proved efficient with the background of the system. The visual interactive rate is 20Hz and the haptic interactive rate is 1000Hz. The system can provide the real-time interaction.
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