I dont know how to break it to you but this is basically already the case, the problem is that there is an inside and outside plane with both being forced to render twosided.
The reason why is in the recent update all map polygons are forced to render twosided even if they arent set to do so by the map creator (there are artistic reasons for and against having polygons be twosided).
MC believes the pro of not being able to "see through" (shoving the camera into the map geometry into the "void" and seeing distant parts of the map) the map outweighs the con of oddities and quirks like this appearing in a few places/certain maps.
There are 2 possible solutions;
- I could make an edit for the map which consolidates the 2 "window" planes into a single centered one or just decrease the gap between the 2 planes to lessen the parallax effect and make it less obtrusive but this may feel odd to some purists/oldgens. (though the twosided rendering on the texture might already feel odd to them lol)
- MC adds garden to the map list where twosided rendering isnt forced.
Gunz is a game from 2004, you shouldnt need a high end pc even with a modernized modified client version of gunz.