The Research And Implementation Of Simulating Virtual Human Walking And Path Planning In Three-Dimensional Virtual Environment

Computer animation is widely used in different fields today, such as game, movie and virtual reality. As a part of Computer animation, human animation now becomes a hot point in application research. Human motion is complex and different from each other along, neither the reciprocity between joints, nor the effect between skin. We have to consider the human's logistic action and deal well with the skin distortion if we want to realistically simulate the human motion. We also have to consider that how virtual human moves and the collision between human and other objects in virtual environment if virtual human is placed in virtual environment.There are three parts of this project: modeling a virtual human motion; simulating the virtual human motion; path planning based A* algorithm in three- dimensional environment.Virtual human model is the base of three-dimensional computer animation. In virtual human animation, modeling a realistically human is the first subject. Multi-level human expression is adopted in this paper. A virtual human is formed by based skeleton level and skin level in this multi-level model. The skeleton level, of which the joints determine the state, decides the basic motion pose of virtual human. The skin level decides the appearance showed.Motion control is most important in virtual human research and also the keystone of this paper. Virtual human walking is the point in this paper. Keyframe and inverse kinematics are combined to implement the virtual human walking in this paper. In the biological research, human walk is divided into two phases: stance phase and swing phase. Based on these two phases, we divide one step into three phases, and design the keyframe of every phase by using 3D MAX, then generate even interpolation curve by using Spline interpolation method. And then, the animation looks more smoothing. And we use inverse kinematics to determine the objects' position on different level in the joint model. And the animation looks more nature and harmony.Before implementing that virtual human walk in the three-dimensional environment, we firstly create a virtual environment, and mapping the 3D environment into 2D environment by using grid method based on frizzy logics theory. Then we use heuristic search for path planning, generating an optimal path from start position to end position, and lead the virtual human roam in the environment. A* algorithm is a heuristic search method used in this paper for path planning. Through continuously search, it can find out the nodes to get the required path.