GLRex

Abstract

I first taught computer graphics programming on PCs in the late 1980s. We produced images with a few platonic solids in 256 colors. Real-time animation was out of the question. I remember writing programs for my classes to do ray-tracing and hidden surface removal that ran at glacial speed. Despite all the shortcomings, the students enjoyed the classes and the images they could create, even though they were relatively simple. Computer graphics was still something of a novelty, and producing any image for the computer to display was exciting. By the mid-1990s things had changed quite a bit. High-end graphics libraries like OpenGL had become available for the PC. Combining them with improvements in hardware (more memory, faster processors, better video cards), it was now possible to do relatively sophisticated graphics even on low-end PCs. At the same time students' expectations were rising as computer graphics became more pervasive in our culture. They are accustomed to seeing very sophisticated computer imagery in the games they play and the movies they watch. Students expect to be able to create visually exciting projects. But beginning students often find their creativity limited by the tedium of building scenes directly in code. GLRex is an attempt to address this problem. GLRex is a simple modeler that provides the user with interactive assistance in creating code for complex images. The user can create scenes with spheres, boxes, cylinders, and cones, as well as NURB surfaces of revolution and extrusion. These scenes may then be exported as OpenGL-based C programs (or RenderMan RIB files) to be used as a basis for more complex projects.