Monday, January 25, 2010

3delight Passes

Point Based Lighting very much interest me right now. As a Vray user I love it's fast raytracing which is really nice for setup and let the processors chew on it kind of stuff like we do at work. Raytracing car reflections is the best and fastest way to get jobs done. But when it comes to doing pretty much anything else, I'm all about the quick and good. Renderman seems to provide that. The only trick is you have to understand how to make it quick.

So I've got to the point where I understand that I need to make a pass that bakes out a point cloud for me to. This should be a pre-pass like a shadow map but it doesnt need to happen all the time but should be automatic enough so when I change a scene I can easily update it.

Now comes the tricky part. Using the point cloud to shade. I've seen examples as a surface shader and as a volume shader. But from how I think it should work, it should be a light shader to cast the fake GI back into the scene. Then it can be a AOV of it's own and separate from the shader calls for surfaces. But I'm not sure if that's how the volume shader works.

But my big curiosity is how you can shade the points in the point cloud with the surfaces on the object for color bleeding. Since I'm so new to this I think I see the code to do it but dont really understand it.

I think by the end of this weekend I need to make my own surface shader ( preferably with Fresnel fall of in reflection and spec with a gloss setting) and be able to make a point file and use it to make an occlusion pass.I'll have to learn about what 3delight calls sets to be able to make all that work.

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