Research And Implement On The Behavior Database Of Virtual Hand

Natural and high-efficiency human-computer interaction is one of the key goals of virtual reality technology, and virtual hand technology is the significant means to achieve this goal, which is also the hotspot in human-computer interaction field. With the development of virtual hand technology, the requirements for third dimension and real time of virtual-hand interaction system are getting higher and higher. To solve out the problems of poor stability and real time in displaying and controlling virtual hand in a long distance, behavior database of virtual hand is researched and implemented in this thesis, which has provided a good basis for improving the stability and real time in displaying and controlling virtual hand in a long distance. The main work and innovations include the following aspects:1. The kinetic regulation of human hands is analyzed in detail. Based on the skeletal structure and joints'movement characteristics of human hands, the hierarchical model and mathematical model are established. Then the motion equations of human hands are deduced based on the homogeneous transformation between space coordinate systems. At the same time, hand motion constraints are researched. Studies on the hand motion have provided a theoretical foundation for building up and controlling the virtual hand model.2. Highly-real virtual hand model is built up based on the method of drawing in segments and mapping hand skin texture. The advantages and disadvantages between OpenGL and 3DS Max software in the aspects of modeling and controlling are firstly contrasted and analyzed. And then the virtual hand model is built up rapidly by use of drawing in segments with 3DS Max software. Combined with OpenGL programming, the display and control of virtual hand model is implemented. The real hand skin texture mapping of the virtual hand model is eventually realized by using Unwrap UVW and Photoshop. This method highly improves the efficiency in modeling and optimizes the effect of virtual model in displaying, which lays a foundation for establishing the behavior database of virtual hand.3. A method of automatically establishing gestures database based on hand motion constraints is presented, in which the behavior database of virtual hand is established. The application of behavior database in displaying and controlling virtual hand in a long distance is firstly researched. And then the gestures parameters of virtual hand are stored automatically by programming with the database development platform of SQL Server 2000. According to the motion constraints among joints, the unreasonable gestures have been eliminated which are incurred in the process of establishing the database automatically, and then the behavior database of virtual hand has been achieved. Meanwhile, new hand motion constraints are introduced in the thesis. The experimental results demonstrate that the amount of behavior database is decreased to 1.43% owing to the hand motion constraints, which substantially decreases the behavior database redundancy and improves the rate of data query in the behavior database. The behavior database performance in querying parameters is lastly improved by utilizing the method of establishing databases and tables respectively, which will provide a good foundation for the application of behavior database in displaying and controlling virtual hand in a long distance.4. Some of the gestures parameters of the behavior database are validated in the experiment. The joints motion angles are firstly extracted based on stereo vision, and then the virtual gestures, which are corresponding to the angles, are displayed by virtual-hand interaction interface program. After that the motion differences between virtual hand and real hand are analyzed in detail, and gestures in the behavior database are queried. In the end, the errors in the experiments have been analyzed in this paper.