Baking Render Passes...

[evanerichards]

Is there any way to bake out some of the render passes? For instance, I set up a multi-matte pass. Can I take that and bake it down so when I export my texture maps I have maps with different colors for different pieces of geometry? Or bake down a world-space pass or a normals pass?

Please please tell me this is possible.

[Morbid Angel]

yes you can bake anything you can render pretty much as a render element. Problem is, what would be the point of baking a world position or a normal pass if they change based on camera/object positions? Multimatte you can bake, just do some rnd your self.

[evanerichards]

Excellent. I didn't mean world space pass. It's true. That wouldn't be very useful. I meant "object space normal" vs. the regular tangent space.

RND eh? I've been looking into it and haven't found anything even remotely close to what I am looking for yet.
Can you give me a hint?

[Morbid Angel]

by rnd I mean just spend some time testing it for your self to figure out what works best for you...

[evanerichards]

Well, I don't know how to do it is the problem. How does one take a multi-matte pass and bake it down? I've seen how to bake in AO and how to bake color (thats you've already created) but I've never seen how to bake render passes.

[Morbid Angel]

hmm...its really simple, turn on vray frame buffer, go to render elements and add your multimatte, make sure it works i.e. you see the colors on the objects as you would expect, then turn on baking. Vray will write out a render element for each of the baked passes after you bake.

[evanerichards]

Got it. Ok. I'll give it a shot.
Sorry I'm so clueless about this all. I've never done baking before of any sort so I'm very new to the whole process.

Thanks for your help.

[evanerichards]

All right. So I see this question has been asked before but only in regards to 3ds max. Is there a way in maya to bake all of your textures onto a single map? I have 4 different objects and they are all UV'd and in their own uv texture set within one uv tile. Yet when I bake, it does each object individually. Is there any way to bake them all onto a single map?

Also, this technique works for multimatte passes, and object id's but doesn't seem to work for normal passes. When I do a regular render the normal pass looks fine, but when I bake it down the whole thing turns the neutral blue/purple color. Hmmmmm.

And a third thing (hope this isn't too many things in one post) is there any way to change the normals element from a tangent normals element to an object space normals element?

Please advise.
Thanks!

[Morbid Angel]

well what I described was for maya actually, both software have similar workflow. In maya for now vray can't bake multiple objects to one map (as far as I know), so you have to combine them (only for your bake), I usually make a separate scene for just that.
I think the reason normals wont work is because by default they are camera based normals. To get any other normals you must create sampler info with additional vray attributes and output normal object to vray extra tex, that will do the trick I think.