Has a map ever used a hotrod custom progsdat in which there was a super special teleporter setup that didn't notify the player with whimsical zinning sounds or fantastical particle displays as to be used to make faux non-eluci..illuci..non-euclidean structures? Also I once attempted to brush out a Möbius band but getting the bendy curve part required tolerances the program and I couldn't manage to produce. 

Don't think so, as to make it truly seamless (i.e. Unreal engine portals, or the... portals in Portal) aside from muting the teleport WHZIRRRIRIRIR you'd also have to disable the player's view being automatically centered when teleporting. Oh, and somehow keep their movement direction and position because normally no matter where they touch a teleport trigger, they get sent to the exact same point where the destination is, so basically remove or change everything that makes a teleporter work as a teleporter. 

Check out Darkplaces engine and warpzones.

https://youtu.be/B7fP6arAfbA 

"so basically remove or change everything that makes a teleporter work as a teleporter."

That seems to be what theyre getting at. "Can this be done in QuakeC?" was the basis of their question. 

But it isn't terribly much different than qc. I can't remember where I found the warpzonelib at or I'd paste a link.

BUT, you could do a similar QC version:
You could make the trigger silent.
You could make it teleport without the particle effect.
You could make the destination ever so slightly above the floor so the player doesn't get stuck.
You could make what is behind the opening/passageway look just like the destination, but you wouldn't be able to convolute spaces as well unless you used func_wall for the areas beyond, toggled them, and separated it so the player doesn't see the toggling. Good luck.

Side note: skip texturing one side of func_illusionary can lend to some confusing areas. 

http://quakeone.com/forum/quake-mod-releases/finished-works/10025-warpzones 

I played around with it a bit, here's a picture of a thin "viewscreen" looking thru to a fully rendered DM2:

https://media.discordapp.net/attachments/308578062126022658/397969864981217283/dp20180102232546-00.jpg 

worked for me, damage_inc 

I meant the "warpzone rar" inside the link does not work. You can't download it, says "Invalid or Deleted File". 

...nah... 

Is there any way to set a list of commands that are executed when maps are loaded rather than when Quake (Quakespasm in this case) is started? I prefer to disable fog but end up always having to open the console and enter "fog 0" on new levels or on loading a game. 

But you could throw something hideous in quake/id1/autoexec.cfg

alias +no_fog_forward "fog 0; +forward"
alias -no_fog_forward "fog 0; -forward"
bind UPARROW +no_fog_forward

So that every time you press the up arrow key it disables fog. 

For a single command, the aliases and +/- aren't necessary, you can just stick
bind <key> "fog 0"
and then press whatever key for the same effect once the map's loaded. 

Keybind is fairly convenient anyway, surprised there isn't an option to disable fog completely in-engine though. 

what is this place for? 

 

Welcome! 

Fog needs to be locked unless player does noclip. Make so that it toggles r_fullbright at the same time. It's either all or nothing imo. 

Why "lock" anything?

Anyway if you have the self control to not turn off the fog, it's simple enough to make it so that a single keybind turns on fullbright, noclip, fog 0, etc...

though restoring the fog value after you leave that "mode" would be awkward, if not impossible.