Rebuilding dome lights in comp - raw light select X diffuse - Very different

[nmitchell]

Hi All,

Apologies if this has already been answered but I have had a hunt for the answer and couldn't find it.

I've been using a Raw workflow for sometime now with my lighting in Vray both in Max and Maya. Recently in Maya I split out a scene into elements
including a Raw Light Select for a dome light. Even without a texture/hdri it doesn't really match the normal dome light -light select (non-Raw) element when multiplied by the diffuse.. it is waaay brighter and breaks the final beauty comp. If I do the old trick of dividing the normal light select pass by the diffuse I get the correct raw element. Am I missing something?.. Or will I always need to use this workaround?

Kind Regards,
Nathan.

[Druski]

Hey Nathan,

How's it gong mate

You might find that the MIS parameter is parking a lot of the dome lights contribution with the GI. It would be interesting to know if the RAW DomeLight VratLightSelect element is an exception to this result.

Try disabling the MIS parameter on your dome light to compare results.

Cheers,

Drew

[nmitchell]

Thanks Drew!

Though wouldn't that mean that when the Dome and GI raw passes were re-combined everything should be back in there? My Raw Dome light is actually ( a lot) brighter than it should be not less light. I'll try disabling MIS and see what I get.

Kind Regards,
Nathan.

[nmitchell]

...still too bright.

[tashko.zashev]

Which V-Ray version is that? Have you added all main passes (Lighting, GI) to the scene as well? They should be there in order to get correct compositing results with RAW elements.

[^Lele^]

RAW light select?
In max, there's only the colormapped one (no Raw in the name), so it would be correct to divide it by the diffuse filter to get to the raw.

[nmitchell]

Hi All,

Thanks for the replies. It's Vray 3.3 for Maya. I have all of the elements necessary, all in Raw form where possible. Vray Maya allows you to split out Normal, Raw and specular Light selects.. very handy and I really miss it when I'm using 3dsmax. Tashko, just do a simple test with a white domelight and a keylight with gi and try to rebuild your beauty with the raw elements from maya.. you'll see my problem.

Kind Regards,
Nathan.

[nmitchell]

Anyone else from Chaos able to chime in?

Kind Regards,
Nathan.

[tashko.zashev]

Hi Nathan,

Just did a quick test on a new scene and the result is exactly the same - brighter comp compared to the beauty.
Then I did some research and found an issue in our system about Raw light select and Dome light wrong compositing results which is the problem that Drew have suggested initially.

Dome MIS - off, gives me exactly the same results. Would you please send me your file just in case? Need to be sure that we haven't missed something.

[vlado]

I generally recommend to not use any of the "raw" passes directly; instead, take the respective normal pass and divide by the diffuse filter (f.e. take the "lighting" element and divide by the "diffuse filter" to get raw lighitng). This is generally more reliable in reproducing the final image. It is also what I do in our denoiser.

Best regards,
Vlado

[joconnell]

I seem to remember that the raw light select doesn't behave too well when you've got an sss material in the scene either - the raw pass ends up getting more info than you want, you're better off using the diffuse version of the light select and making your own raw with the diffuse filter.