Baking Ambient Occlusion in Maya 8.5

CheeseOnToast

I've been attempting to use the new "transfer maps" option to bake AO from a highpoly to low. Every time I do it, I end up with pure white in the UVed areas, on a black background. If I crank up the number of rays it takes longer, but still has the same result. So it's doing *something*, but not producing the maps I'm after. Anyone else run into this, and sorted it?

Whargoul

I prefer to bake the AO on my high rez, then transfer after (put it in the colour channel and transfer that). It just seems easier to me to break it into 2 steps, to help fix errors on each step iondividually than trying to get it right all in one go. "Is this seam from the raycasting of the transfer, or a wrong AO setting?", etc. Just do some crappy auto-UV on the highrez if it needs UVs and bake out a huge AO map, then deal with the transfer. ALso - you can't adjust the "spread" of the rays with the transfer method, only with the bake then transfer method.

I have had it working as you are trying it though - maybe your distance is too low? Or the UVs aren't in 0-1? or there are multiple overlapping shells?

CheeseOnToast

Cheers War, I think it's just bugged. A friend has the same problem, and we've tried everything we can think of to fix it. Looks like I'll be doing it the long way as per usual.

Daz

Have you tried changing the file format? Try a .tiff for starters. Make sure there are no lights in the scene too. Not sure, but it might respect lights.

CheeseOnToast

Yeah Daz, I went through tga, tiff (8 bit and 16 bit), bmp etc. I'll double check the lighting thing, but I'm pretty sure I tried it with nothing but the defaults in there.

CheeseOnToast

Sorted it. Rediculously simple in the end. For all other maps, you can stick the highpoly in a layer and hide it, and the map will be generated fine. The AO map requires both the low and highpoly to be visible in the viewport......

Whargoul

Oh yeah - I had that problem too! Seems that mental ray actually looks at the visibility of the objects, while the maya renderer used for the other transfer correctly ignores it in this case.

Panupat

After you bake the occlusion map to the high-res, how do you transfer it to the low res? Looks like Maya is trying to resample everything when I use transfer maps.

CheeseOnToast

Transfer "diffuse", and untick everything else.