Maya transfer map - Ambient occulsion artifacts

Meteora · Sep 2013

I'm having an issue with baking ambient occlusion from a high poly to a low poly model. Whenever I try to bake, I always get these weird artifacts from baking and am unsure of what I am doing wrongly. The results has always been the same between three different meshes I tried to bake:

Here is one of the models I have set up ready to bake with the transfer map settings. Everything above the panel is floating geometry.

Bartalon · Sep 2013

I would try putting the LP closer to the HP and use an Envelope (in the Target Mesh section settings).

Meteora · Sep 2013

What's the difference between mesh and envelope?

So far your solution solved most of the artifacting but I still get a few random artifacts, may have to paint them out. I haven't tried the other two models, but here's hoping that it'll help.

Oh, one of the models is basically right on top of the high poly mesh, but it still gets artifacting (top right window in the Photoshop picture). The strangest thing is that it only affects the mirrored half of the model when I try baking it in earlier bake tests. I checked the normals, exported it out as a OBJ but still cannot solve it.

Also there's some weird stretching issue with my bake on another model, even though its a little bit more than a plane. Would that be related to the topology of a low poly model?

Thanks in advance.

Bartalon · Sep 2013

An envelope is a fancy word for a cage. Maya can automatically duplicate and convert your LP model (mesh) into a cage (envelope) which is indicated in the viewport as a transparent red mesh. The envelope tells Maya how far out to "look" for details. You generally want the envelope/cage to extend just as far out as you need with no huge gaps.

More info on cages (Section 8.10), and the related task of baking normal maps here.

The artifacting you are still getting may be due to Maya trying to double-bake AO information for both sides of your mirrored surfaces into the same UV space. Be sure that your mirrored UVs are resting outside of the 0-1 area. Offsetting mirrored UV shells exactly 1 unit will still allow the model to properly read from any texture file but will not interfere with baking.

Stretching may be due to improperly unwrapped UVs. Be sure you don't have any UVs that take up zero UV map area (generally caused by non-mirrored UVs stacked directly on top of others).

Brygelsmack · Sep 2013

I don't think I've ever got a good AO bake from Maya. Try Xnormal, should work fine for what you're doing here. You can use a plane as a cage and the results are really good.

Meteora · Sep 2013

While I mirrored my surfaces I did not leave the mirror UVs overlapped, I laid them out and connected the UVs of the mirrored surface together. As such, there aren't any overlapping UVs in my unwrap. Unfortunately, that did not work. And for the record I deleted the UVs on the high poly, but I doubt that has any influence on the bake.

I double checked my UVs, deleted them, did a planar projection but the results remain the same. It actually got worse when I decided to delete some unneeded edge loops. Here's a side by side comparison, the mesh on the right is a duplicate of the left displaying the ambient occlusion bake.

The image below is the old mesh, which has a slight stretch but did not have weird artifacting. Oddly enough when I was deleting edge loops from the mesh, the UVs remained.

At this point, I am at a loss of why this is happening. My ambient bakes used to work correctly, but now its all fudged up. I may have to take up Brygelsmack suggestion and try other baking solutions, Maya does not seem to want to work. Still, I want to know what's up with this for future reference.

Maya transfer map - Ambient occulsion artifacts

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