HDRP Reflection Probes Blending

[crimson wind]

Hi, I just don't understand how blending between reflection probes is supposed to work.
Here you can see 2 overlapping reflection probes, with a Blending Distance > 0. As you can see there is a hard edge where the 2 probe volumes meet. How do I get rid of that? Changing the Blending Distance doesn't seem to do anything.

[atomic belfry]

Which render pipeline?

[crimson wind]

HDRP

It seems like this is the best you can get???

[atomic belfry]

So, does is blend distance working here?
It certainly should work

[crimson wind]

it's working but it's not working good as you can see

[atomic belfry]

I'm not sure what you mean
It looks like how I'd expect it to look if you're blending a bright probe into an enclosed interior whose lighting doesn't match the probe

[crimson wind]

You think so?

The window is right there, I feel like it should penetrate much deeper and not lead to this sharp difference in brightness

Now, I've baked the lighting with only 1024 indirect samples, maybe that would improve with a higher sample count

[fathom surge]

that's already a lot. Usually I bake with 32/64/32 samples and it looks fine

[crimson wind]

Damn, that sounds very very little. I tried with 2048 indirect samples and it didn't really change anything anyways. Maybe I should play around a bit more with the probe placement

[fathom surge]

I think it's better if you put 3 reflection probes here

2 for the corridors and 1 for the corner

[crimson wind]

That does make it look a bit more uniform. Unity's already complaining about the amount of reflection probes though. What do you typically do here to stay under the limit? Just write a little script that deactivates probes outside the players view?

[atomic belfry]

I feel like it wouldn't but that's just me
There can be sharp differences in lighting in many places physically, but the only thing wrong I see here is that there's reflections in occluded areas
Which is not really avoidable except by better probe placement

I think probe limits are per mesh or per screen tile, same as with lights, so they shouldn't have a cost if objects in their range are not being rendered
Assuming they're not realtime and that your environment isn't just one mesh

Box projection can improve the accuracy in hallways, often helps a lot with bright reflections that seem to have an inexplicable source

Most importantly the amount of light from specularity and from diffuse, baked or otherwise should match as closely as possible

I'm not aware of all technical limits HDRP has for reflection probes though, so I wouldn't rule out that disabling them manually may help in some way