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View Full Version : Bump mapping and ambient occlusion-Maya

catalu
02-23-2007, 08:31 PM
Hello,

I am looking for a way to combine an ambient occlusion pass with a bump map. I am using maya 7.0, and the preset occlusion pass (which uses a custom surface shader and mental ray.)

However, I run into a problem trying to add occlusion and bump mapping. I am making a street scene, and am currently using a bump map to define the bricks of buildings. I would like to get the soft self shadowing of occlusion in the bricks. Does anyone have any techniques for adding a bump to the occlusion shader?

Thanks for your help!
Catalu
Marcel
02-24-2007, 09:35 AM
That's probably not possible, because the occlusion shader works on 'real' geometry and a bumpmap makes no changes to the actual polygons.

Why not multiply the bumpmap on the colour texture in Photoshop, that should lead to the same effect?
m4gnus
02-27-2007, 04:38 PM
you could however assign the bumpmap as a displacement map and then bake the ambient occlusion, because displacement is considered when baking ao(at least in maya 8.0)

regards,
m4gnus
lemonyfresh
02-27-2007, 08:36 PM
What you need my friend is the mix20layer. This is essentially a layered shader for Mental Ray. Download it here http://www.pixero.com/downloads_mr.html. You can make a blinn or whatever with a bump on it and put into the base color of the mix20layer. Put your mib_amb_occlusion into the color.1 cbanel under layer.1 enable layer.1 and set the blending mode to multiply. And render render render.
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