While developing a gamemode for Garry’s Mod I eventually gave up due to the inability to logically separate players from each-other on a server, effectively creating different scenes/dimensions that each player would be in, without having multiple game-servers.
While it was possible to do it to a degree using functions like using Entity:SetPreventTransmit (which was broken for a long time) and overriding hooks like EmitSound (only worked for build-in entities) & GM:ShouldCollide, it was extremely hacky.
Will s&box / does source2 have some method to have a number of players inhabiting the same map space, but logically & network separated from each other / seeing and interacting with different dimensions?
The best analogy I can think of right now would be the Condos from Tower Unite. When TU was still a gmod server, they had to create a map with the same room duplicated x amount of times, which meant that if all those rooms were physically occupied, no more players could effectively play. To overcome this limitation, the only way i can think of currently is a way to logically disconnect players and entities to effectively create different ‘dimensions’ the players inhabit.
I am keenly awaiting s&box to reinvigorate the big ideas and concepts that in source1/gmod I just couldn’t feasibly accommodate without bending over backwards thrice.