Interactive control for viewing 3D objects based on MFC and OpenGL

The construction of 3D objects and their viewing control are key problem during 3D visualization process. General procedures for developing application software based on MFC and OpenGL were proposed according to object-oriented programming methodology and thus a GLView class was derived from CView class. Spherical coordinates were adopted to characterize the observation point´s position and the view direction. The transformation formula of twisting, translating, rotating and scaling were deduced according coordinate transform rule between global world coordinates and local view coordinates. An OOP algorithm was developed to finish these transformations by the response of a mouse or keyboard message, a dialog or a Timer. It was demonstrated by many cases that both the intuitive control and the quantitative control for viewing 3D objects have been provided conveniently.