# mikela

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Peon
1. ## (u,v) to (x,y,z)

thanks, Mario! When you suggested using dP/du I knew you were onto something, but your Du(uv) revelation really had me wondering for a while. Your final solution reminds me of my vector algebra--it looks right, anyway. When I plugged it into my shader it did what I wanted it to, but I can't say for sure untill tomorrow because I have lots of ugly displacement artifacts right now...
2. ## (u,v) to (x,y,z)

This should have an easy answer, and I hope someone here helps me before I put too much time into finding it... I have a vector in (u,v) coordinates that I need in (x,y,z) coordinates, object space. I'm in the displace context so I know P and N. How do I do it? Unless there's some space transform I don't know about (I seem to remember coming across a texture space transform in the docs, but can't find it now) I think I would have to know exactly how my UVproject has layed things out. For example, if I lay uv coords on a torus so that u always lies in say the xy plane, then I can find u in object space with the N vector (which is orthogonal to uv). I don't think this kind of solution could handle a variety of uv layouts, though. Hmmm, maybe it's just been too long since I've done much 3D math... BTW is there a difference between (u,v) and (s,t)?
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