I need to draw a stress contour map with data that I have from a Finite Element program. Each data point has x, y, and z spatial values as well as a value for stress. The stress values are mapped to a color.

I am currently using an openGL toolkit (Eyeshot) and I have written an algorithm that does a pretty good job of drawing the contour map using triangles, however, the algorithm is complicated and prone to error given different sets of data. The complication really comes from the fact that the default shading mode is gouraud, and therefore, it is necessary to triangulate based at least partly on the stress value at each vertex, otherwise, the map is not an accurate representation of the stress contours.

I have been told that a custom shader is the way to accomplish this task. I have searched the net, and while I have found several references to custom shaders and some examples, they seem to be too low-level for me to understand well enough to adapt to my task.

Does anyone know of open source examples of this type of task? Barring that, does anyone know of a good reference that would help me understand how to accomplish this task?

I have a long history in programming on Windows using C, C++, C#, and various other languages, however, I am a complete beginner when it comes to openGL.

Thanks in advance!