OpenGL and Motif are a powerful combination. Using both APIs allow X applications programmers to get the most out of both Motif and OpenGL.
Still another way to integrate OpenGL rendering with widgets is the Open Inventor object-oriented 3D graphics toolkit which renders using OpenGL and integrates with X Toolkit widgets. Open Inventor allows you to specify 3D scenes in an object-oriented fashion instead of low-level OpenGL rendering primitives. If you are interested in object-oriented 3D, check out the recently published Inventor Mentor [5].
The source code presented in this series is available by anonymous ftp to sgigate.sgi.com in the pub/opengl/xjournal directory.