LC #42 Pipers Alley

View Full Version : AO as a Channel

06-18-2007, 08:38 PM
I want to Add my scene's ambient occlusion as a channel within the pass setting and I use the "Store color in channel" from within the Render tree ... the problem is that when I apply the occlusion to the whole partion within the pass all what I get in render is a white I can solve this problem ??

thanks in advanced

06-19-2007, 08:52 PM
Why don't you use an empty pass with an ovverride for the ambient occlusion?
Is very quick, but actually I don't know if you can "store color in channel", just check the AO pass!

07-06-2007, 08:03 PM
Cuz i want everything in on single pass , man ??

07-07-2007, 10:17 AM
well im not sure whats your problem exactly

But here goes three possible solutions

1) If you are adding ambient occ through a render channel when you mix it back with the mixlayer node make sure your setting are on multiply and set the color almost to white

2) if you do not want to add occlusion into the shader then make sure in the mixlayer node u have it all the way to black

3) make sure the occ shader outputmode is either on bent or sampled depending on how you lighting the scene

Hope that helps

07-07-2007, 10:22 AM
I have used AO as a channel, but the setup is not a one click solution.
Have a look at this video:

- As a quick guide insert a "mix 8 colors" between the material node and your phong/blinn shader.
- Connect your phong to the base color of the mixer.
You have to insert the mixer in every material which is used by objects for ambient occlusion
- create a partition for all AO objects
- Get an override and add the color 1 property of a mixer node
- select the override, open the Rendertree
- connect a ColorStoreChannel to the override
- connect XSI AO Shader to the ColorStore
- open the ColorStore and add a channel called AO for example

Hope that helps
I think sometimes it is easier to setup an seperate pass for AO, but it depends on the scene and how many objects are invloved. For inserting the mixer a script would be handy.


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07-07-2007, 10:22 AM
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