ambient occlusion ray direction

Introduction to Maya - Rendering in Arnold

This course will look at the fundamentals of rendering in Arnold. We'll go through the different light types available, cameras, shaders, Arnold's render settings and finally how to split an image into render passes (AOV's), before we then reassemble it i

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# 1 12-03-2011 , 08:52 PM

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how to i change the lighting direction for the ambient occlusion to match my scene lighting

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# 2 12-03-2011 , 09:08 PM

The thin red line
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I dont think you can on light direction(will be proved wrong) if you show a shot of the problem there might be another solution..........dave

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# 3 12-03-2011 , 09:41 PM

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the model is lighted from underneath, but the occlusion is as lighted from above, i guess i could flip my model upside-down for the occlusion pass but that seems odd method to me

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# 4 12-03-2011 , 09:54 PM

The thin red line
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ambient occlusion is created from the models geometry not a light source that is way I said show us a shot a sreen shot to see if we can help..........dave

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# 5 14-03-2011 , 03:21 PM

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i think i understand the problem then, i have a white floor under the model to reflect light up onto it, on the occlusion pass i guess this is actually making some areas darker

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# 6 15-03-2011 , 05:29 PM

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yep works ok now

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# 7 15-03-2011 , 10:58 PM

The Nurb Herd
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i think the problem is misunderstanding ambient occlusion... which creates contact shadows when one object is close to another. you can turn off ambient occlusion on specific geometry. would this be helpful to you?

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# 8 16-03-2011 , 08:05 AM

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thanks Dom for clearing that up.

Jay

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# 9 16-03-2011 , 09:53 AM

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if you want to have an object not occlude itself.
select the geometry, create an attribute called "miLabel" then in the ambient occlusion node you will see an attribute called id nonself. I think (can't really remember) but if you set both these attributes to the same value, the geo will not occlude. i could be wrong about the values, so i would just play around with the settings.

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