Physical Sky for lighting + HDRI for reflections, is it possible?

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juangea
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Physical Sky for lighting + HDRI for reflections, is it possible?

Post by juangea »

Hi there.

I'm having a problem, we have the desired light for our scene with the physical sky, however the reflections in the pool are too dull due to the lack of detail in the sky (which is logical), so I wonder if there is a way to separate the environment lighting from the reflections for this situation.

Thanks!
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DionXein
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Re: Physical Sky for lighting + HDRI for reflections, is it possible?

Post by DionXein »

First thing came to my mind is using different scenes to render separate variants of scene and then combine it with compositor. For second scene with standard sky you don't need too much samples - around 20 would be enough.
Also there is a lot of AOV passes you can combine in many ways.
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B.Y.O.B.
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Re: Physical Sky for lighting + HDRI for reflections, is it possible?

Post by B.Y.O.B. »

I would also find such a feature useful, but AFAIK it's currently not possible in Lux.
(Although the use case for such a split is usually the opposite: you want to use a high-res LDR for reflections and a low-res HDR for lighting, to save memory compared to one high-res HDR for everything).

What I would do is map the HDRI on a plane and use it for emission, then place it so its reflection is visible in the pool. You can hide it from the camera if necessary.
kintuX
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Re: Physical Sky for lighting + HDRI for reflections, is it possible?

Post by kintuX »

Indeed... it was "Smart IBL" in the old days
http://www.hdrlabs.com/sibl/

All major engines have this feature and can use different maps for lighting, refraction, reflection & background.
Maybe with OCL frozen this might become feesable
juangea
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Re: Physical Sky for lighting + HDRI for reflections, is it possible?

Post by juangea »

In this case the situation is different, we have a physical sky because we prefer the lighting of it, but we need something to reflect, the plan idea is what we are using, and it works for the pool, but it does not work for the windows (because they are not in the same angle)

We also tried with an spehere that is not visible to camera, has transparent shadows and has an emitter, but it does something very weird to the lighting, so it's not working either.
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Re: Physical Sky for lighting + HDRI for reflections, is it possible?

Post by kintuX »

Same principle applies, you still have options to set either PhySky or IBL.
You can check it with RPR for Blender.
https://github.com/GPUOpen-LibrariesAnd ... n/releases
rprENVoverrides.jpg
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