Throughout the game, particular piping parts seem to have issues with their models, causing problems with their material type, reflections, texture application, etc.
These parts in particular are the pipe corner pieces (90 degree turns) and the pipe rings (I think they’re called drip rings?).
An example of one of these glitchy pipe parts is at position -3718.626221 -4890.050293 -3432.692383 on bm_c1a1d. This is the very first time in the game that I noticed this glitch.
The glitch affects the appearance of the parts, causing the texture to look fuzzy, and giving the parts a plasticine specularity (plastic-style reflection). It also causes any interaction (walking on, or shooting at) to sound like plastic, rather than metal. Any shots fired at them leave the same bullet holes that any plastic object has, rather than the dents that other metal objects usually feature when shot at.
Example (from Lambda Core) of a corner piece: https://steamcommunity.com/sharedfiles/filedetails/?id=440886930 (note the bullet holes)
Note that this doesn’t affect all corner pieces and rings, but rather those of a certain pipe size for a particular commonly used pipe model set.
This is a pretty trivial bug, but as I said this glitch is seen throughout the game. It was also in the mod too, and I played through the mod so many times… I would love to finally have this plastic pipe glitch fixed.