Max ambient occlusion baking error thing

erik!

Right so I've been baking AO maps for my scene right? I've done a couple different methods just to mess around to see what works best for me at the moment. So far so good right? Mostly. There are a couple objects that cannot be baked for some reason. When I try using Mental Ray to bake an Ambient Occlusion MR map, the baked map comes out black. When I try baking using a skylight I get this ERROR that pops up.

I kinda need the AO since nearly everything else has it so far. I'm currently working on ways to get around it, but thought I'd post this to get some info on what might be causing the error. Enjoy.

the error again in case you missed it

Noren

I remember having that, too and also solving it. More than that my memory fails me. :P
Try to check the properties of your low and highres meshes.
Perhaps "renderable" or "visible to camera" are unchecked. Also having an empty object without any faces/vertices will cause the projection-dialog of rtt to fail.

aniceto

Had that error a few times before. Turned out the solution was to create a box and attach the low res mesh to it.
perhaps reset xform would work as well.

erik!

Aniceto your method of attaching the mesh to a box worked. I don't know how and I don't know why, but it worked, thanks. Can you explain why attaching the mesh to a new box works?

JDinges

Ok here's my non technical oppinion on it-

Reseting the xform would probably have had the same effect. Basicaly attaching it to a new box is reseting all the crap you've done to it while modeling, unwrapping and such. It's like over writing the history of the building and giving it the properties of a new box. Thus getting rid of any problematic bugs (like the AO render error) that may have been produced while creating the building.

But yeah, resetting the xform generaly has the same effect. And I'd recomend doing that every so often to get rid of possible problems you can't see.


Hope that makes some sense.

erik!

Actually, resetting the Xform didn't work. When I clicked "reset Xform" it flipped the object's normals. I'm not sure if it's supposed to do that, but I flipped them back once it was collapsed back into an editable poly. I tried render to texture with a skylight and I got the same error.

JDinges

Doh oh well, gotta love the crazy bugs that pop up. Atleast you were able to work around it with the box trick.

Eric Chadwick

Tried and true methods for resolving bugs in Max...
http://www.neilblevins.com/cg_education/file_crashing/file_crashing.htm

The reason your normals flipped is because you mirrored or negative-scaled the model at some point. You can do this without penalty though, if you only mirror at the sub-object level (selected polys/elements) instead of the object level.