CS - Sun Rays coming through walls in R4 render

[argosurvivors]

Describe the bug
The sun rays can burst through walls

To Reproduce
Steps to reproduce the behavior:

1. Set R4 and Start new game
2. enter in the huts in swamps
3. Move around in the direction of sun
4. See error

Expected behavior
A sun rays should come inside only from windows or open doors

Screenshots, videos

sun_rays.mp4

BugTrap error report
No crash

Desktop (please complete the following information):

OpenXRay Release Master Gold build 9856, Feb 1 2026 (Windows 64-bit, static)
GitHub Actions build 6237 (21565295480) from commit[62b2e33] branch[dev] (built by OpenXRay/xray-16)

[argosurvivors]

I got the message from the player who claims he found the cause and solution, I will quote him here

**I finally was able to fix this on the r4 renderer. The culprit for this is the setting 'r2_sun_depth_far_bias' in the user.ltx file in appdata. By default, this setting seems to be set to -0.00002. It kind of seems like any negative value causes sun shafts to bleed through the geometry. Setting it to 0 seems to fix this issue entirely. My sun related settings follow. Playing on max settings with a 3070. All of the floating point values in these settings can be altered in the console (`) as well to demonstrate what different values do.

r2_sun on
r2_sun_depth_far_bias 0.
r2_sun_depth_far_scale 1.
r2_sun_depth_near_bias 0.00001
r2_sun_depth_near_scale 1.
r2_sun_details on
r2_sun_far 100.
r2_sun_focus on
r2_sun_lumscale 0.3
r2_sun_lumscale_amb 0.5
r2_sun_lumscale_hemi 0.9
r2_sun_near 16.
r2_sun_near_border 0.75
r2_sun_quality st_opt_high
r2_sun_shafts st_opt_high
r2_sun_tsm on
r2_sun_tsm_bias -0.01
r2_sun_tsm_proj 0.3

Alternatively, just set 'r2_sun_tsm' to off and use the default settings for everything else. This setting seems like it controls how and when near and far sun shadows are rendered, which can have a pop-in effect. **