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Light passes - good quality how to?

Posted: Mon Apr 24, 2017 9:26 am
by sbstnc
Hi All,

I've taken to rendering some light passes out recently, but they always turn out a lot noisier than my main pass. I assume this is because, once they are all added together, the noise is less noticeable.

But say I'd like to set up a separate take in C4D just for light passes, in order to get them out cleaner. Are there any recommendations anyone could give in order to get cleaner light or passes out, without the beauty or main render? Does it have to calculate the main render in order to split out the light passes? If so then I need to oversample my main render to force the light passes to be cleaner?

Hard to tell what the samples need to be to get clean light passes, as you can't judge from the beauty and LV can be loooong waits to work this value out if you have a troublesome scene.

Cheers

Re: Light passes - good quality how to?

Posted: Wed Apr 26, 2017 10:13 am
by aoktar
It should be fine when you do same process of mixing in a compositing software. They don't look bad to me on tests but you can increase samples of emission for some emission.

Re: Light passes - good quality how to?

Posted: Fri Apr 28, 2017 4:00 am
by sbstnc
Thanks Aoktar,
I was trying with a scene with some area lights and also small light sources, emission samples were all around 10,000, but the light passes turn out very noisy compared to main render. Even if all mixed together, the final output, while appearing to have the same overall brightness levels around the scene, is noisier. I thought there may be a way or parameter to increase quality of these renders.

Say I render 8 light passes (maybe overkill but let's say I want control), and in post I end up wanting to add or subtract one or more of these. As I said, when using all passes together equally, image looks OK but still not as clean as actual beauty). But if I subtract just one, and that one is noisy, I am making my final output look more noisy. Similar, if I add just one or two, that's adding noise as well.

Possible to render only light passes and no beauty? I turned off beauty in the passes tab but it still output one. Also then, how to tell how many samples (emission or render samples) to get clean light passes? Trial and error?

Thanks

PS: Enjoying 3.06 a lot!