Research And Development Of The Graphics For Solidification Simulation Based On OpenGL

The technology of Solidification Simulation of Casting has been widely used in production and it is composed of the pre-processor, calculation and post-processor. The function of the post-process in solidification simulation is visualization of the data of calculation, with multiple kinds of pictures to help users to understand the simulation results. For many years, under the platform of MS Windows, the traditional development method of visualization of CAE software is based on GDI graph method. In this method, the developers should transform the 3D entity information to 2D graph, in which much matrix transform work should be done. However, the drawing efficiency of Windows GDI is very low. So it is necessary to find a new convenient and efficient way to develop visualization. The OpenGL is now an universal 3D technology directly and the developers who use this technology may not concern about many complicated coordinate translation and 3D shadow calculating, so they can pay more attention to the processing of algorithm and data structure. In the post-processor of "HuaZhu CAE"software the management of surface element of grid and the numerical mouse based on OpenGL are investigated in this paper. In this module, algorithms are focused on the including searching surface, searching contour line, combining of surface element as well as combining of contour line, and then a series of data structure is built. The algorithms and the data structure are employed for reducing the grid information of 3D entity, so as to improve the display velocity of the 3D entity. At last, the rotating, zoom in and zoom out, cutaway and so on of several kinds of numerical pictures are developed, and numerical mouse based on OpenGL is developed helped by reversing 3D position and refreshing display. On the study of the visualizing 3D accurate locating technology, aimed at cutaway view of STL entities and the assembly of them, single STL entity can be rotated and zoomed in real-time, and the algorithms of section contour line making and the visualizing 3D accurate locating technology were put forward and developed. To be convenient for users to modify the 3D coordinates they have got, they can operate on these 3D coordinates, such as editing, deleting, inserting and so on.