Frozen lake is black during night

[mztulip]

Describe the bug
1.As in title. Lake is black during night. It changes at morning. In vanilla during night it looks like ice during night.
Included save shows night/day transition.

Save-game/Log-file/Screenshots/Video

lake_day_night.zip

Original engine video during night. Lake is snowy white.

lake.webm

[Try]

Hi @mztulip , and thanks for report!

This is a general issue, with this type of graphics engines: it can render well only opaque objects base of GBuffer, and semi-grandparents are 'special' case, that often become inconsistent with the main renderer.

Depend of your shadow setting, you may also see lower resolution shadows in the ice - that normal.

[mztulip]

What you mean that it depends on shadows settings?
I tested it with parameters -rtsm 1, -vsm 1 and it looks the same.

[Try]

What you mean that it depends on shadows settings?

This is with rtsm/vsm (transparency can source only low-res projective shadow):

This is without:

[Try]

I guess it solved

[mztulip]

No it is not solved, it is still the same(checked on commit 143bed3). I have idea to check it with another GPU.
Maybe I a does not understand exactly what you mean.

This is a general issue, with this type of graphics engines: it can render well only opaque objects base of GBuffer, and semi-grandparents are 'special' case, that often become inconsistent with the main renderer.

It means that it can not work as in original engine, due to new implementation and must be as is?

I am learning how graphics rendering works, but it sometimes is hard to understand problems. This is huge task.

During day shadow tree looks ok with -rtsm 1.

Anyway main problem is still present that during night lake is black/dark.

[Try]

This is how lake look for me:

No longer black. Maybe you on a wrong commit somehow?

[mztulip]

Git log shows:

[mz@archlinux opengothic_5]$ git log
commit 143bed36f4dfde4b021dbd21363ae8537f2219f9 (HEAD -> master, origin/master, origin/HEAD)
Author: Try <try9998@gmail.com>
Date:   Sun Mar 8 21:41:45 2026 +0100

    working on ice-block fix
    
    #906

Fresh compilation in new directory to avoid mistake.

I will try in next days on different PC with different GPU than AMD.

[Try]

I am learning how graphics rendering works, but it sometimes is hard to understand problems

You are welcome to ask questions) If something particular - can be as part of a issue, or even better - can just drop-in on discord.

Specifically for lake: OpenGothic uses mostly deferred rendering. It renders objects with lighting (plain texture and geometry normals) and then lights world as separate pass. This helps a lot with balancing - no gpu thread processes way more work then the other. Problem - only one layer of materials can work with deferred. So translucency drawn separately on top, with completely different code.
Since there are 2+ pieces of code doing same task - copy-paste error are always a problem.

[mztulip]

Ok it works, but not after loading save. I go to bed for sleep then it works.