实现牙体预备触觉交互仿真的图形显示

介绍了在牙科手术训练触觉交互系统的虚拟手术环境中,通过材料去除速率控制构成牙齿的网格变形实现牙齿被切削时材料去除过程的图形仿真.针对牙体预备操作和触觉交互装置输出力的特点,在交互系统的虚拟环境中,当工具与牙体模型发生接触时,所有进入工具空间范围的顶点都会沿着其外法线的反方向进行投射,投射量受控于材料去除速度,且网格变形速度不超过真实的牙齿材料去除速度,同时针对网格的变形位置绘制虚拟工具.通过限制网格变形可以动态的实现牙齿被切削过程的形状变化,图形显示逼真同时没有滞后.

Graphics Rendering in Dental Training System

This paper introduces the graphics display of tooth preparation by mesh deformation and generation in the virtual environment of haptic display system.The mesh deformation is controlled by human's operating and can solve the problem of fast cutting.In virtual environment the tooth and the tool are constructed by triangle-mesh.When operators move the tip of haptic device to cut the virtual tooth,the vertices of tooth mesh which are surrounded by the virtual tool will move to the surface of the tool.By deforming the mesh of tooth,the graphics display will be realized factually with no delay.