global AO via light

[randrews]

Hey guys and girls.
In maya 7 it was possible to create a point light and under the MR attribs set it to area then pipe the AO texture through it so you had scene global AO. This is rather useful if you want to use AO on the dgs or env AO (with bent normals if ya like) on the architectual material (rather than the inbuit one) as these don't have an ambient arttrib.

However in 8.5 MR supports maya's area lights so the old MR area light bit has gone which has kinda made this method defunct. Anybody got a work around at all?

Cheers
Rob

[svv3d]

Hoto create global AO in MAYA

1. Create Area Light
2. Check "Use Light Shape"
3. Set Type - User
4. High Samples = 1
5 Custom Shaders -> Light Shaders -> mib_amb_occlusion

[sebkaine]

thanks for the tips svv3d, i was trying to achieve this since a long time :o !

i try your tricks, it works find BUT the time to render is multiply by 2 if you compare it with a basic surface shader connection. I'm afraid that the area light function is quitte heavy , and contain some extra "greedy " code. Does anybody know an other way to achieve this without the extra render time cost!

in renderman there is an indirect light node, you plug an AO node in it and the result is added to every diffuse component in the scene with no extra cost for AO computing ! i'm trying to achieve the same things in MR !

thanks in advance for your help guys !