An Analytic Solution Or Collision Response And Improvement Of FCPF Algorithm In VR

With the development of VR technology, it has been used in many applications and has got good results. The startling reality of motion object plays an important role in VR, and it is also the difficulty and keystone of VR research. Collision detection and response have an important influence on reality of the object motion; therefore, they are critical content in VR research. In this thesis, the algorithm of collision detection and response for some rigid body is studied and some good results has been got:Firstly, after studying the collision response we provide an analytic solution based on physical characterastics under the special condition. The research ofcollision response based on physical characteristics is the essential method for implementing reality motion of object in VR environment. We discuss the basic principle and conditions for collision response based on physical characteristics, and we present the analytic solusion of object velocity and angle velocity after collision, suppose there is no friction between object surfaces. We can establish the object motion equation looking upon the velocity and angle velocity collided as the initial condition, and the moment when collision occurs as the new initial moment, then we can simulate the collision response with startling reality for the real object and can meet real-time requirement.Secondly, we study the algorithm of the initial collision moment and collision point between balls. In virtual environment, ball is a special object, which can be simplified using convex polygons and although we can use convex polygons to describe the ball and can make use ofthe convex polygons algorithms, but ball is simpler than any other complex convex polygons and collision detection is also simpler than other objects. In this paper, we study the algorithms for the initial collision moment and collision points between balls only and study on increasing the speed of collision response.Finaly, We improve FCPF (First Collision Point Fast) algorithm at the condition of constant acceleration, FCPF is a rapid algorithm used to compute the earliest collision point and collision moment between convex polygons. The both object plain movement and rotation as well as improvement of computing precision with needless decreasing t are considered in this algorithm. The algorithm can be used to compute the earliest collision moment and all collision points between arbitrary polygons. The algorithm is provided at the assumption that the line velocity for the mass center of object and the angle velocity are constant vector in the detection period. But in realvirtual environment, acceleration does exist such as gravity. In this paper, we improve FCPF algorithm giving the assumption that the acceleration of mass center is a constant then analyse the result, give the concrete algorithm for two main computing processes.Based on the above algorithms, we design and realize the virtual object collision simulation system using OpenGL and VC++. The C++ class library can be extended and reused.