Ambient Occlussion Bake Failure.

Mecha · Dec 2011

Hi PolyCount,

I have a rather wierd error while trying to bake an ambient occlusion. I have only encountered this with this specific model so far.

What I've tried so far (wich in no way affect the results of this error)

Different UVs.
Another Highpoly model.
Tighter or wider projection cage.
Fiddling about with various settings in mental ray / render to texture.

All this with no avail, so my question is does anyone know straight of the bat what could cause this error?

Regards,
Mecha

JohnnyRaptor · Dec 2011

What software u using?

Mecha · Dec 2011

Doh! Knew I forgot to mention something..

3dsmax / Mental Ray

Oniram · Dec 2011

im not really seeing what the error is. how does it look on your model?

Zipfinator · Dec 2011

Oniram wrote: »

im not really seeing what the error is. how does it look on your model?

I'm guessing those blotchy spots all over are the errors. That ain't normal. Not sure how to fix it though... Maybe try baking with Xnormal?

Mecha · Dec 2011

Due to the purpose of this model I am unable to show it in its whole.

However, I've made a more specific picture to show what I am talking about:

The red areas have some artifacts that I am unable to get rid, I get these both cage and without. Also stated in the first message, I've tried to bake from two different highpoly models. These artifacts are located under the arms and on the inner thighs.

The green areas is how I would expect the gradient to look with a nice and smooth transition from darker to light.

A sidenote aswell, I get no artifacting on the normalmap in these specific areas, only in the ambient occlussion.

Regards,
Mecha

Ace-Angel · Dec 2011

Edit Poly on Low -> Hide Faces/Mesh

Now bake again.

Mental Ray, sometimes, for some reason, bakes your low-poly also, I know, it sucks.

Please note Mental-Ray is horrible at baking, which is a pity, since it's the only thing able to bake the AO by default, the other solution would be to try V-Ray.

The other solution would be to use xNormal, just export you High as triangulates OBJ, and export you Low as a Mesh with the Cage modifier in SBM format. Then tick box for Cage, and bake.

EDIT: Oops, didn't see your latest post, hmm, in that case, how many samples did you put up for the render? Mind show us your settings?

Mecha · Dec 2011

Ace-Angel wrote: »

Edit Poly on Low -> Hide Faces/Mesh

Now bake again.

Mental Ray, sometimes, for some reason, bakes your low-poly also, I know, it sucks.

Please note Mental-Ray is horrible at baking, which is a pity, since it's the only thing able to bake the AO by default, the other solution would be to try V-Ray.

The other solution would be to use xNormal, just export you High as triangulates OBJ, and export you Low as a Mesh with the Cage modifier in SBM format. Then tick box for Cage, and bake.

EDIT: Oops, didn't see your latest post, hmm, in that case, how many samples did you put up for the render? Mind show us your settings?

Thanks a thousand times over! The HideFace did the trick, how such a small thing can be so painful to figure out. I would've never tried that in a million years.

Again, thanks a bunch!

Case closed.

Regards,
Mecha

Mark Dygert · Dec 2011

Yea I've stopped using MR to bake normal maps, its way too slow and buggy. The one thing it does that other rendering engines don't, is bake AO but then you have to deal with quirks like having to hide the Low Poly mesh, but then it fudges up the padding so you're still screwed....

YEAH MENTAL RAY! (I hate you so much)

marul · Mar 2013

Finally found this thread after having the same issue. Thanks a lot for the workaround!

Ambient Occlussion Bake Failure.

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