[HDRP] Underwater draws through buildings

[huwb]

Describe the bug

Discord user Puppetmaster reported an issue where the underwater effect appears through a building:

He suggests it may have been introduced in Crest HDRP 4.1.

It might be that the surface is being culled by unity using dynamic occlusion culling. These tiles wont be added to the visible list, and therefore won't be registered to draw into the ocean mask. However I could not reproduce this effect locally.

Actually, maybe this is due to multiple water levels. I've enquired.

Versions
Unity 2019.3.9
Crest HDRP 4.1

To Reproduce
How can the developers reproduce this bug? Are you able to reproduce the issue in the example content/scenes?
Please include steps to reproduce the behaviour, with the example content ideally so we can follow the steps on our side.

Platform

• Editor or standalone?
• Platform (win/mac/...)

Hardware
What hardware are you seeing the issue on? GPU model is particularly useful.

Additional context
Add any other context about the problem here.

[Puppetmaster3Dxxx]

My specs:

• Win 10 pro
• 2x Nvidia GTX 2080ti
• Unity 2019.3.9f, HDRP 7.3.1
• Crest 4.1 (from the Package Manager in Unity)

The Problem does only occur when I use Occlusion baking in Unity with those settings:
Smallest Occluder: 1
Smallest Hole: 0.1
Backface Threshold: 75

As soon as I clear the baked occlusion, the problem is also gone. I made video for you.

2020-04-22_12-14-07.zip

[banan5555]

This is same case like ours:
#456

And problem is not only with occlusion culling.
Small line without occlusion culling:

Big line with occlusion culling:

[moosichu]

The underwater mask depends on a contiguous ocean surface being rendered. We've been unable to reproduce these issues ourselves. If anyone is up for it, a RenderDoc capture could be really helfpul here. If you don't know what that is I'm more than happy to explain and walk people through the steps.

[huwb]

After messing around i found a repro here without baking occlusion - at runtime disable one of ocean tiles in the mid or background by setting the gameobject inactive, then put the camera looking through the island in main.unity (close-ish to the water so underwater is active):

[banan5555]

@moosichu here is my RenderDoc capture with simplest case - cube and crest:
https://drive.google.com/open?id=1pVeoXQmxYFJBasGQ5qyrm2nKmM3-SThM

screen:

[moosichu]

We are working on a solution to both problems. This is seprate from the horizon line issue, but both are being worked on :)

[moosichu]

I thought this was fixed but managed to repro it, have a fix incoming.

[daleeidd]

4.3 is out with a fix for this. Please reopen if you still experience this issue

[originalemanuel]

4.3 is out with a fix for this. Please reopen if you still experience this issue

is it available in the asset store?

[daleeidd]

@originalemanuel Yes