3D Surface Graph

[link19]

Anyone have any experience in drawing a 3D surface graph, like in Excel. It shows trends in values across 2 dimensions in a continuous curve. Im quite new to openGL and do not know how best to proceed. Any hints or links or anything else would be appreciated.
TIA

[Michael Steinberg]

Well, you mean something like a terrain? You can create a heightmap, create a mesh by many triangles (each two form a quad in the heightmap, which is a rectangle). Then, you can add smoothing data and smooth that out. If you however need to create that curved data yourself, I don't know how to do that.

[link19]

Ill try and explain...A contour would be this 3d surface graph from above. If you have excel, you can open it up and enter some dummy data; at least 2 series. Then chart it with a surface type. What i would like to render is similar to this. Hard to explain in words. Each series is mapped out horizontally on the graph; with increasing values of each series climbing the y-axis. At different heights, colours represent specific ranges. So that in the end, depending on data of course, you have shapes of colours on top of each other.
After re-reading this i dont even follow...

[Michael Steinberg]

You could mail me an excel example file!