LC #42 Pipers Alley

View Full Version : ambient occlusion - diffuse not showing

05-16-2008, 11:13 AM
hey guys,

so my diffuse maps don't appear when the sun (spotlight) in my scene isn't hitting it. below is the render tree. what am i doing wrong?

05-16-2008, 11:30 AM
I wouldn't bother with ambient, you could plug the AO into the diffuse, and then the image you have into the bright slot of the AO.

05-16-2008, 11:57 AM
thanks simon.. but that doesnt work. the only thing that works is plugging the AO into the material's surface shadow and photon slots.. the problem with that is that the object ignores my sunlight which is supposed to cast hard shadows. any thoughts?

05-16-2008, 12:52 PM
Check the dark color on the AO node for alpha. Set it at 1, or it will alpha itself out. Also, it's not a good idea to use PSD's in mental ray. Stick with a flat format.

05-16-2008, 01:03 PM
the setup you have is fine, you just need to plug the diffuse texture into the "bright" slot of the ao shader as well, otherwise your ambience wont have any textures will it..

if it doesnt work something else is wrong, are you sure you have UVs for example?

05-16-2008, 08:08 PM
yes i have UV's. also, would PSD be alright if it's flattened?

i will try your suggestions. thanks for your responses!

05-16-2008, 08:13 PM
psds are fine, xsi always reads the flattened version of it, no matter how many layers you have in there. PSDs can be a bit more memory hungry due to the fact that MR cant read them natively, but other than that they work just fine.

also, if you can't figure out whats going on here, export that one object to a new scene and try to fix it there, it makes it much faster to track down a problem.

05-16-2008, 08:28 PM
thanks wurp!

plugging in the texture into both the diffuse slot of the phong and the bright slot of the AO solves the problem.

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05-16-2008, 08:28 PM
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