[Cycles] Ground for HDRi Environment (aka Shadow / Light Catcher)

Im not sure if got what are you asking for. In general - sure, hdri strenght influence direct and indirect (interior) light intensity.

And as expected incresing hdri strenght influences brightness of both …

Is it possible to bright only dark areas more(indirect lighting? Hdri strength exposures the bright surfaces

You can try to decrease “Multiply” node and increase in Render Properties - Film - Exposure

But since it seems, there is not a need for a specific HDR image - try to find another HDRi with softer shadows (lower contrast) instead.

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I am gonna try and write the results.

[https://drive.google.com/file/d/1pZSJcQi8RSpvQz05tBzguVAmiSvlkSEg/view?usp=sharing ]

couldn’t figure out light settings. I shared the file. Could you help me?

My aim is to increase light bouncing of interior scene.

2.6 GB not a small one :slight_smile: I will try to check that, but as I said place you are mentioned is in a shade so probably different hdri would work better, also you can add another light to improve some area condition.

Anyway can you adjust render in image editor (Photoshop, Gimp) and attach so I have better understanding of desired result? Its not clear for me from your screen. Thanks

In meantime - with your file I will have to wait on Monday to try at work, at home its too big to work with effectively. I just noticed you use in world two HDRis, one for lighting second for camera visibility? Thats waht you want? At first it doesnt make too much sence for natural-realistic result. At second it consume more render memory (for just envi jpg will work the same).

BTW it seems to me your Background node use quite extreme high values (10 and 80) on other hand you lowering Color Management Exposure (-3.8 or so), that results with no effect.

Background Node > Strenght 1 / Color Management > Exposure 0
Screen Shot 2020-10-18 at 21.29.37

Background Node > Strenght 20 / Color Management > Exposure -4
Screen Shot 2020-10-18 at 21.29.05

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Yes!

If I lower the hdri light, the interior gets dark. When I increase the hdri light, some of objects become overexposed.

The main problem is normal hdri light doesn’t bounce inside the interior well. You can try

For that I attached example with spheres (above) - where high contrast (overexposed spheres and darker shadows can be decreased (no overexposure in brightest point and brighter in shadows), that is what you are asking for.
BTW I thing you missed point of quoted text of mine by you here - When you reset Exposure in color management to zero you can clearly see you can use lower Strength of HDRi for the same result. That is not a solution of course for you, it is just a note to the setup.

You can’t expect as white in shadow as white lighted directly. That is why I asked you to post a manually corrected a part of image with desired result to see your expectations. To bring highlights down and shadows brighter means flatten result. So some screen would be really helpful for me to be sure we are looking for the same result.

Naturaly it bounce as it should. The same happens with real camera - you can’t get bright interior without overexposed exterior behind window. Dynamic range is too high. To compensate this scale blender use Filmic that brings these wide range into some valuable scale, but it is not unlimited.

Your file is time consuming, so before I try to adjust your setup I want to be sure what result are you expecting.

Note: Speaking to “indirect” light - you can try to render it as separate pass and increase or decrease as you like in compositing, probably this could be a solution for you too.

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OK I checked your file. HDRi used for lightning is “ambient” already so there is no reason to use nodes I used on screen with spheres.

If I delete all lights and I use only HDRi and Sun …

  • Background node 1 (for Camera Ray)
  • Background node 40 (for Glossy Ray)
  • Color Management - Exposure -3 / Gamma 3
  • Sun Strength 80

I started with nodes to setup basic and adjusted in color management to lower overexposed parts and highlight shadows, sun is just end point to get some shadows.

And I don’t think you can expect more, place you mentioned is the deepest corner any other multiplying of indirect (bouncing) light will add light to whole scene. So previously suggested indirect pass wouldn’t do much because most of the light there is indirect.

If you still expect more light in that area you would have to use other lights (like point light with bigger size and lower intensity).

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