Shadow casting

OpenGL doesn't provide shadows out of the box (which means OpenTK doesn't either). I have implemented shadow mapping with OpenTK, which needed a fair chunk of code but wasn't all that complicated.

A quick search on "shadow casting tutorial" pointed at NeHe Lesson #27. It is written in C but someone has also ported it to C#. The code should be fairly trivial to port to OpenTK, just ignore the parts that create the window and OpenGL context (use OpenTK.GameWindow instead) and translate the OpenGL function calls to their OpenTK equivalents (e.g. GL.Enable(EnableCap.StencilTest) instead of glEnable(GL_STENCIL_TEST)).

Ah, you are right there's no C# port of this tutorial. My mistake.

Shadow mapping performance is pretty good actually, my last project runs in realtime on a weak 8400M card, using one directional and one point light with VSM-style shadows. HDR and relief mapping both have a larger impact on performance than shadow maps on that project.

So is Shadow Mapping better (performance wise) than the algorithm offered by the NeHe tutorial? Maybe I should be focusing on real time shadow mapping instead of procedurally creating them.

Did you ever add your VSM code to OpenTK?

I downloaded their code and will port it over to C# (as best I can). If Fiddler doesn't already have the port/general library for this, I'll go ahead and send it to him.

hmm ok so the demo in that site is an SDL based shader (a few of them) - this is beyond my skill level to port over to OpenTK as I think it would involve building the same shaders in GLSL. I'm trying to derive the algorithm from their paper so I can write it as a library (from scratch) instead, but wow, that math is pretty hardcore. The results are VERY good and have good performance stats, so this is definitely worth it (especially if I add an ambient occlusion section to complete my shadow library).

-TheNerd