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Old 04-24-2013, 03:30 PM   #1
josh247
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Josh Bainbridge
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Ambient Occlusion Shaders in Renderman

Hi all,

Just been having issues creating ambient occlusion in renderman for maya for use as shadows later in comp. I have a scene where a character needs to be integrated with a background plate. There is a floor and wall planes that receive occlusion and also create it on the character itself. This is what I want but the issue is that it creates ambiant occlusion on itself in the corners of the room. How can I make the matte geometry not produce self ambiant occlusion?

Cheers,
Josh
 
Old 04-25-2013, 10:46 PM   #2
earlyworm
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Will Earl
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It relatively simple assuming your doing a separate shadow casting pass. For ambient occlusion you need to set the Diffuse Visibility on both the character and the room - you need to make sure the character is visible and the room is invisible.

In RMS you use shared geometric attributes to do this...

http://renderman.pixar.com/view/sha...tric-attributes

Note that other types of shadows use Transmission Visibility rather than Diffuse Visibility and reflection occlusion uses Specular Visibility.

In your beauty pass for your character you'll want to make sure that Diffuse Visibility is on for both the character and room.
 
Old 04-25-2013, 10:46 PM   #3
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