Fixed flickering shadows

[tritonas00]

Example terrain: https://sim-monsters.com/files/file/3734-orlando-2021/

Before: https://streamable.com/jc4591
After: https://streamable.com/nos1a2
(I don't know why it recorded on fast forward 😆)

Also fixes sloppy rendered survey map with shadows:
Before:

After:

[tritonas00]

@paroj i go a bit blind here, is this the right way to handle depth fighting issues?
Why on windows VS 2019 exposes the issue while VS 2017 doesn't?
On linux side, it happens with some gpus (like it happens on my laptop intel 5500 and it doesn't on my desktop intel 4600 gpu)

[paroj]

yes, but it also comes with its own problems:
https://docs.microsoft.com/en-us/windows/win32/dxtecharts/common-techniques-to-improve-shadow-depth-maps#peter-panning

[tritonas00]

It creates this issue https://discord.com/channels/136544456244461568/189904947649708032/958169316526796830

[paroj]

It creates this issue https://discord.com/channels/136544456244461568/189904947649708032/958169316526796830

this is to be expected when you move geometry forward/ back a little.

To be safe, you should only use depth_bias in shadow caster passes and for decals.