The research on the interactive display of three dimensional CAD models based on the viewing volume of OpenGL

Open Graphics Library(OpenGL),the development standard of 3D graphics,is adopted for the interactive display of three dimensional CAD models.The display mechanism of OpenGL is deeply studied,and then a method based on the viewing volume of OpenGL is presented and detailedly discussed for the interactive display.Based on the display system of OpenGL,the translation of the viewing volume in the eye coordinate is applied to the implementation of translation display of CAD models.The scale of the viewing volume is used to scale the display of CAD models.With the help of vectors,the parameters for the rotation of the Eye Coordinate are computed for the rotation display of CAD models.The running of program illustrates that this method can interactively display the three dimensional CAD models efficiently and flexibly.