Grid pattern for deactivated shadow filtering

[Langbart]

to reproduce

Start the random map Anatolian Plateau and look at the stone when toggling the option Filtering in the graphics settings under Shadows. See GIFs below for more clarity.

# Autostart
# You can also choose another map, but for consistent testing and comparison between different alphas, this map was chosen. 
binaries/system/pyrogenesis -conf=mod.enabledmods:"mod public" -autostart="random/anatolian_plateau" -autostart-seed=999345625 -autostart-civ=1:cart

bisect

[25562]

reproducible

A24b it is visible a little bit

A25b it is very obvious

latest GIT version [26913]

related

Investigation with elexis

[19:53:05] elexis only the environment.js affects that map
[19:53:22] elexis so it might be that the angle of the light now hits in such a way that makes it more obvious
[...]
[19:57:15] elexis the SunRotation line
[19:57:19] elexis that might have triggered it
[19:57:31] elexis elevation too I guess
[...]
[20:14:10] Langbart Taking the existing values and simply lowering "SunElevation"  to 0.7 fixes the issue (mostly)
[...]
[20:15:24] Langbart as soon as you move the camera ...
[20:15:31] Langbart it itches a little bit, definitely noticeable
[20:15:52] elexis but thats not the root cause of the bug
[20:15:57] elexis the bug is the root cause of the bug
[20:16:02] elexis for any bug
[20:16:17] elexis it shouldnt matter how the angle is, so thats not a fix, thats just hiding the bug
[20:16:42] elexis the bug must either be a wrong texture, model, or shader
[...]
[20:33:31] Langbart I used those values that were introduced with 25562 for SunElevation, SunRotation and SunColor ... the problem could be reproduced with Alpha XXII, but as extremely visible with Alpha XXV 
[20:34:44] elexis it sounds like a shader/material thing

If you use the values before [25562] from the ​environment.js file, the problem becomes less obvious (it hides the problem). See the image below for more clarity.

[Langbart]

bisect

[Langbart]

add findings

[Langbart]

Adding a patch that "hides" the problem.

vladislavbelov argued on ​Phabricator

It doesn't fix the ticket, so the ticket must not be closed. But the fix might be committed as soon as accepted until we have a proper solution.

[wraitii]

In 26934:

Improve shadow artifact problems without shadow filtering in some A25 biomes/maps

Without shadow filtering, artifacts may appear at some angle (shadow bias issue). This change ssome settings so that these are less common.

Reported by: langbart

Accepted by: marder

Refs #6552

Differential Revision: ​https://code.wildfiregames.com/D4681

[Freagarach]

Pushing back.