Big if. You had screwed up if you left such a setup as one long vis chunk. Level designers would place vis boundaries strategically along a corridor to control this behavior. It was a bit of an art form but not exactly hidden knowledge, even the levels that shipped with quake SW had this kind of tuning built in.
Weird that at no point in this article is the engine overall referred to as what I and presumably most level/mod designers referred to it as - 'The Dark Engine'. Still, she's a classic. Tuned beautifully for the sneak/rpg gameplay of Thief and System Shock. Not at all suitable for the high speed multiplayer FPS gameplay of Quake. A comparison between the two is always interesting to see.
When a scene contains a truckload of triangles, culling them all one at a time like that does not win you as much performance as you might think. You always needed to do additional things on top of it.
This let you do stuff like (and I'm working from memory here) have a 15k triangle budget from which you could easily develop a 300k triangle environment, as long as you were VIS-ing well enough that a player never saw more than 5% of the environment from any common position. Non-visible areas were essentially completely free, because they weren't even considered at runtime. This was a significant edge over culling approaches such as the one you mentioned, at a time when that kind of edge mattered a lot.
That said, IMO this approach was tuned for extracting maximum performance from the hardware available at the time (~Mid 1996- late 98). It showed it's age heavily from Quake 3 onward and was quickly overtaken by engines adopting somewhat different approaches (e.g. Unreal) quite quickly.
Good times - great game!
Years after we broke up we remained friends, and one day she called me asking for help getting it to run on her then-new Windows Vista PC. I never could get it to work correctly so I cobbled together a working PIII era machine for her with Windows 2000 installed, and period correct GPU, and she was in sneaking heaven!
These days the GOG version plays perfectly well on modern hardware and OSes, no need for hacks or period hardware anymore.
About ten years or so ago, Drake: Uncharted (plus its sequels) on the kid's PS3 was recommended to me as a worthy game to play. But I found it boring, having to face a fistfight and primitive shooting only after 5 mins into the game, so I didn't bother.
I played it new. I really felt the sense of tension and attention to detail of being stealthy, and the corresponding consequences of failing to be stealthy.
I could be wrong but, AFAIK, Doom 3 was the first game with real time shadows and dinamic lighting and every game before that employed various tricks that simulated those instead.
The original Quake used a mix of pre-baked lightmaps and dynamic lights, just like the original Thief; Quake 2 (the OpenGL renderer, anyway) added character shadows that’d react to dynamic lights, so in some cases Quake 2 actually got pretty close to the goalpost.
Great game. Thief and Descent were pretty challenging compared to quake.
"The core technique for rendering texture mapped polygons with decent precomputed shadows is very similar (identical?) to Quake. Thief used light mapping and a surface cache to store the lit surfaces. I refer you to Mike Abrash's articles."
Mike Abrash is a cool guy, not as well known as Carmack but had as big, if not bigger, impact on the gaming world. Got to sit in a panel with him and Carmack once at GDC to talk about networking stuff (I wasn't in the actual panel, but it was a tiny room with about 20 people plus the panelist)
Seems to be downloadable at https://www.ttlg.com/forums/showthread.php?t=141708 (and have a bit of a niche following)
Googling the name also turns up a comprehensive 4-part YouTube video series from 2012-2013 showcasing the UI and how to build a level: https://youtu.be/C0dHgEaUCEQ (20:02), https://youtu.be/A1wm0RZXlh0 (41:50), https://youtu.be/UlVJHCcaUAo (27:45), https://youtu.be/yyq5Z2ioM-0 (11:31)
