I tried an experiment in VR this evening that made me only visible through obstacles by inverting the depth buffer, and only afterwards realized that it also resulted in my avatar's Z-depth becoming inverted, drawing it back to front... but not the parallax depth, so the things in back were blocking the things in front while being further away, depth perception-wise. I didn't realize because I'd only tested it in the Unity editor. not VR. I accidentally inflicted an impossible, incomprehensible shape on everyone
Edit: yes, this made me visible in the entire world except for within direct line of sight
