Real transparency?

Hi, I’m working on an animation where i have a mesh burn down. I have a good particle system, great material, but I need the mesh to fade out. I’m using Ray transp right now, but since the alpha is not 0 i can see the mesh’s specular areas. (Note I have SpecTra slider set to 0). I have also tried Ztransp, but when i use it, it pushes the mesh “in front of” the particles so that i can’t see them. Any ideas how to make this work?

Well, one solution to your particular problem would be to make a shape key for the mesh and push it out of the way as it burns down.

As far as transparency goes, you could use Ztransp, render out the particles, then composite them together. Is there a reason you can’t set the alpha to 0?

Oops, bad english. Sory, It was a wrong formulation. I meant that whem alpha is 0, it’s OK but when it’s some other value, i can see the mesh’s specularity. Thanks anyway, the shape key is a great solution. I’ve actually used the transparency because i couldn’t work out a better method…

Certainly one way to do it is with compositing. (And don’t forget that [i]Speed[i] IPOs can be run backwards!) The object, which actually remains unchanged, is occluded by a traveling mask that is “Alpha only,” so that it gradually disappears. The sparking particle-system that explains it all away is sandwiched in front. And the whole thing is then layered into the completed scene.

But… “whatever works.” Shape-keys are really useful for a whole lot of things.