Explain relationship between Light Intensity and HDRI sky

Unity Engine
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1

I was playing with Point Lights in a scene and I noticed that they tend to “absorb” light from the sky at high intensity levels.

I’d like to have bright, volumetric point lights WITHOUT affecting the skybox and the rest of the light in the scene. Is that possible?

There’s probably something fundamental about lights that I don’t understand, so feel free to explain that too.

6345057--705093--Light Intensity Impact on Sky.gif

2

Do you have a volume or settings with ‘automatic exposure’ as that is what will happen unless you change to fixed exposure.
There is little space for custom/non-real lighting in HDRP it seems

3

@andyz Thanks for the suggestion but I can’t find anywhere to change to fixed exposure. My example is just from a default HDRP template in 2019.4 in a new Scene, with an added default Point LIght. So everything is default.

4

hi, the problem indeed should come from exposure. There is a default auto-exposure mode in the HDRP Default Settings (Look for ProjectSettings → HDRP default settings) - https://discussions.unity.com/t/777661

Also I will suggest you have a look at this tutorial video:
https://www.youtube.com/watch?v=yqCHiZrgKzs

There is little space for custom/non-real lighting in HDRP it seems
Such a problem isn’t related to non-real lighting but just auto-exposure. You will have the same issue with builtin if you used the same scale of intensity.

hope this help.

5

Thanks @SebLagarde

Is there any documentation anywhere on the Exposure module? That’s a lot of settings.
6371268--709242--exposure.JPG

Absent that, would still be helpful to understand how to separate effects since it seems like more of a layer thing than a volume thing. My goal is to control intensity of some lights WITHOUT changing the look of other background objects. Maybe its 2 cameras so the different exposures don’t compete?

6

Hi, documentaiton is here: Exposure | High Definition RP | 10.0.0-preview.27

If you want to prevent your background from changing with more light, then you should switch from auto exposure to a fixed exposure.

Note: Fixed exposure is a single float settings

1 Like
7

Huzzah! Docs FTW!

Two suggestions to make this resource more accessible:

  • Add the reference hotlinks to the HDRP volume overrides like HDRI Sky, Fog, etc and to the HDRP Default Settings page in Project Settings, as well as hotlinks from each section to its section in the docs
  • Give the toplevel link to docs it’s own sticky post in the forum. I totally missed it scanning the very good, but very long Getting Started thread
8

And the issue of exposure is addressed very well around the 20:40 minute mark of the video