Ambient Occlusion question

[Streetwise]

So why do my window frames wig out on the AO pass when I'm using the same texture as the beams?

[M.Max]

Flipped normal I guess

[Streetwise]

Flipped normal I guess

Silly question, but how do you check for that?

[M.Max]

Just select these faces in editpoly/mesh and check if the red color bright then it is okay if it is dark click flip to make it bright.if you are not sure just select them and choose flip and do test render.
Edit normal modifier can also show the normal iirc.
Xview tool can show you flipped faces in green too:
https://knowledge.autodesk.com/suppo...B20F2-htm.html

[Art48]

Shouldn't the "Double Sided" checkbox in the AO texture fix it, too?

[Syclone1]

might be double faces too, can try under global settings tab change the Secondary Rays Bias to 0.001

[Streetwise]

I ended up adding a "normal" modifier and having "Flip Normals" checked fixed the issue.