how do you use the irradiance and AO vop nodes ?

[nmn]

Hi everyone

All said in the title i guess, let us say you create a basic surface material, then you want to add irradiance to it using the vop irradiance node, how would you integrate it ? you just add it to the final color result (that's the correct one from what i know...anyone can confirm?)? or you use it on its own? ...etc

same goes for the AO node you just multiply it with the final ambient color, then you add the other components ?

I had a very good explanation from DaJuice in another post but in that one we clculated every pass alone, but since using this method gave me different results from using the irradiance vop node ... so i'm wondering ...

Cheers

[rob]

Well ....

I would consider building the shader in VOPs akin to the same way you build a comp for your shot . So if you take a Occlusion you would mult it with the diffuse pass and paint pass and of course you would want to be able to weight that value. But saying that if you calculated AO all the time every time you wanted to render a test it would get tiresome and you would be waiting forever to turn round renders.

Hence that's why so many places either bake the AO for objects and then multiply it in with the diffuse and paint , handy because you get a feel for your shot without waiting for AO to be calculated. Or they just render a separate occlusion pass.What I would term an Arb Export. This can be dropped into your object shader it can contain all those extra passes you might want like ID and such.

Its funny you should want to discuss this as I am about to try and solve the issue taking baked UV information and multiplying it within a shader using different UV layers. For an Auto baking tool I am working on. !

Best Rob

Edited July 2, 2009 by rob

[nmn]

Thanks for your answer rob , ye that's what i thought about the AO, but we should multiply it with the Indirect Lighting result right ? i mean if we only have direct lighting and to be "correct" no AO should be taking place, we can still do it of course to inhance the image or if we are faking the Indirect Lighting with direct lights for example.

what about the irradiance , should it be added if i'm not mistaken, and if yes where? i mean in which phaze of the network we do add it ? just before giving the result to Of or ... else ?

Cheers

Edited July 6, 2009 by nmn

[brianburke]

Thanks for your answer rob , ye that's what i thought about the AO, but we should multiply it with the Indirect Lighting result right ? i mean if we only have direct lighting and to be "correct" no AO should be taking place, we can still do it of course to inhance the image or if we are faking the Indirect Lighting with direct lights for example.

what about the irradiance , should it be added if i'm not mistaken, and if yes where? i mean in which phaze of the network we do add it ? just before giving the result to Of or ... else ?

Cheers

I think you're right about the Irradiance, but I wouldn't recommend scaling your diffuse by ambient occlusion - direct light occlusion is handled shadows.

I like Diffuse+Ambient*AO+Spec+Refl+Irrad