Resolved How to control the intensity of the global illumination skies contribute to a scene

In HDRP, both global illumination and skyboxes are controlled by one of several sky overrides at a time. This is nice for automatically generating outdoor scenes that look correct from relatively few parameters, but transitioning to an indoors scene with very few openings to the outside looks wrong on account of the global illumination contributed by the sky being too intense. I thought I could compromise by changing how bright the sky is when the player camera is inside a volume that encompasses said indoors area, but there doesn't seem to be a way to change how bright the sky will be without also changing the way the skybox looks. I simply want to say something like "when indoors, only apply a fraction of the sky's automatically generated GI", is there a way to achieve this that I'm not aware of?

 

From your 'inside' volume adding a new SSGI with only setting the `Raymiss` to `Reflection Probes` only should do the trick.

If you additionally want further blending control of that, and if SSGI supports weight blending, you can use the weight fade on that volume to mix back in SSGI from the outside volume as.
This could be useful for per building tuning for example.

You can also use the `SSGI debugger` in the `Render Pipeline Debugger` to visualise the GI.

 

1. You can decouple the visual sky that you see, from the sky that contributes to environment light:

Environment lighting | High Definition RP | 13.0.0 (unity3d.com)
See the section "Decoupling the visual environment from the lighting environment".

2. You can add a local volume for indoors, and a an "Indirect Lighting Controller" override to it. You can then dim the indirect diffuse lighting level which will keep the sky light from sneaking indoors where it shouldn't be.

The downside in that while indoors, if you look outside the outside areas will also appear to be occluded from indirect light.

 

Thanks, the indirect lighting controller solution is basically what I was looking for, though the other suggestions are a nice bonus! I'm aware of the limitations of this solution, but most games seem to do it this way, so it seems like an acceptable way of achieving what I want.