Ambient Occlusion Bake in Maya

siBerman

Hello,

I've been trying to get rid of some strange artefacts that occur when i use transfer maps to bake the AO from a high poly to a Low Poly mesh. I've baked the normals with no problem but am getting these black canyons in the folds of the sheets (modelling a bed). I've tried everything i can think of, max distance, all the other settings, but just can't get it to work.
Any suggestions would be awesome.

Thanks Heaps

Simon.

btw. i'm using maya 2012 on OSX Lion.

bk3d

are you using final gather? i usually bake AO without final gather on. Mental ray does do a pretty good job without final gather.

bugo

final gather? no dont use final gather, you would be baking AO + indirect lighting. You want only AO, I know you tried distance already, but try moving some of those verts that are close to the mesh and see if you can get inside only instead of average, you can try using an envelope to get the verts close.

edit: dont get me wrong, and I know this is not the subject, but your low poly mesh has tons of not useful tris.

r_fletch_r

Looks like your cage isnt covering your high poly fully. max distance on the mr shader is only a measure of how far it looks for occlusion not how far to shoot a ray from the low poly.

Also like Bugo says Final Gather has no connection to AO calculation, the only effect having it on during a MR AO bake will be is to slow it down.

siBerman

Hey, thanks heaps for the replies. I've just done a test with the cage covering the entire high poly, and it seems to have fixed the problem. Is this generally a good idea regardless of which map you are baking, ie. normal?

Also @bugo, i appreciate any input Are the redundant tris just the ones on the base around the foot of the bed, and the ones around the seam? I was taught to model thinking in quads, so I avoid tris in my meshes, but if they'll be triangulated for the engine anyway, i assume i can model some in. I mention this because cleaning the mesh will be much easier if i don't have to worry about preserving quads.

I've gone off topic, but thank you all for your help!!

r_fletch_r

yup make the cage cover the hp totally.


Keeping all quads doesnt apply to low poly models. if you can reduce your vertex count by using triangles then do it. rule of thumb for a normal mapped asset is remove as much geo as you can while keeping the shading and sihlouette looking good.

bugo

I agree with what r_fletch_r said.

r_fletch_r

bugo wrote: »

I agree with what r_fletch_r said.

sorry man, i just realised i pretty much restated your post there :poly122:

siBerman

Thanks heaps for the tips, all coming along nicely now

siBerman

I'm happy for you JamesJO, but i'm not exactly sure what 'it' is?

-Em'-

Its a bot reported.

By the way, i think you can use floating geometry : you don't need to make your low poly in a single object because it will causes unwanted subdivs and edge loops.

bugo

r_fletch_r wrote: »

sorry man, i just realised i pretty much restated your post there :poly122:

No, you didn't, no worries