3 guys wrote the world's first game that rendered a truly three-dimensional world, and they did it in software, and it ran at 20+ frames per second on my Pentium 75. It's not quite correct to talk about Quake the way you would talk about almost any other software project.
BTW, if you're curious, Abrash goes into greater depth at the end of his "Black Book of Graphics Programming", which I think is now freely available online.
Abrash's Graphics Programming Black Book was my favorite programming book in high school. I read it everywhere I went, even when camping. I highly recommend it to anyone who wants to learn how the lowest-level graphics primitives were drawn before GPUs. The first half of the book also makes for an excellent guide to optimizing algorithms by reducing overhead and converting to assembly language.
My only complaint about the book was that the publisher (Coriolis?) included a notice at the front saying that no code samples, algorithms, etc. could be used in any project without their express approval, but most of the algorithms and code were previously published elsewhere.
I used to do graphic demos in Pascal, in 286 mode, using hand-coded procedures in assembler for the graphics parts, using Mode X for buffering the animations, like 320x240 resolution, 256 colors and only one virtual screen (although more were possible).
Doing 3D was pretty cool too - I couldn't do fancy stuff, but I could display and rotate 3D objects, drawing only visible polygons, draw textures and even have simple lighting.
To me it seems weird how kids work these days. I don't know what a pixel shader is for instance.
Don't forget Wolfenstein 3D. While not directly germain to the topic at hand, this makes Quake second and probably more likely its development was handled like any other software project.
I think you misunderstood the parent post. Wolf3D was not really 3D, nor was Doom after it, and many other FPSs that came around at that time. Quake was the first really 3D FPS (e.g. you could walk under a bridge without "tricks").
I don't know what development process they had at ID at the time, but given that it was a Carmack project, I very much doubt it was anything like "any other" software project.
Descent came out over a year before Quake and was full 3D (except the annoying hostage sprites). It may have taken advantage of being set in a mine to have twisty passages that obstructed views, but it did have its fair share of wide open spaces (most reactor rooms, for instance). I think the reason Quake gets all the credit is due to its popularity, not for being the first.
Descent used affine texture projection, which makes texels slide around as your viewpoint changes, unless extremely small polygons are used (they weren't). It also had extremely simple lighting (intensities set at vertices, interpolated in a simple gradient in screen space like the texture projection). Neither of these things means you're wrong in calling it "full 3D", of course. I don't recall if the topology allowed room-internal objects other than the robots; I think it did.
There was also Driller in 1987 which had full 3D representations though you could rarely take advantage of it. It was based on the Freescape technology which I played with in 3D Construction Kit in 1991 and that was definitely full 3D in terms of movement (though not a game in itself).
> Quake was the first really 3D FPS (e.g. you could walk under a bridge without "tricks").
Sometimes the tricks were cool.
In Bungie's Marathon for instance, the map format allowed you to have multiple rooms occupying the same physical 3-d space. Imagine a spiral stair case that doesn't go up or down, you just run around and around this long corridor like a manifold mobius loop. Quite fun in multiplayer maps with radar. Also worth noting that Marathon was the first game that allowed rocket jumping due to being able to look up and down slightly.
Obviously Marathon had nothing on Quake, but it was really a great multiplayer FPS for its day.
I also remember Mechwarrior 2 came out before Quake and was mostly 3D-ish. Granted most of the levels were flat but you could jump (with jump jets) and climb on top of some terrain.
BTW, if you're curious, Abrash goes into greater depth at the end of his "Black Book of Graphics Programming", which I think is now freely available online.