使用OpenGL绘制4个茶壶（调用OpenGL函数生成），通过设置OpenGL材质，使4个茶壶分别呈现出塑料、金属、石膏和瓷器的特性。-The use of OpenGL rendering 4 teapot (OpenGL function calls generated), by setting the OpenGL texture, so that four teapot were showing a plastic, metal, plaster and porcelain featur