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Doom wasn't 3D!

Posted: Sat Oct 15, 2016 7:30 am
by MattyC64c
This might be a bit late and some of you probably know this already, but Doom wasn't 3D. No, it was actually a 2D game, the 3D was just an illusion. Wolfenstien 3D wasn't 3D either nor was Duke Nukem 3D. The inability to look up and down wasn't a limitation of the engine's of these games, it was of course because they were all really just 2D games.

Which would mean that the first real 3D first person game engine would have been Quake, released in 1996!

https://www.youtube.com/watch?v=zb6Eo1D6VW8

Re: Doom wasn't 3D!

Posted: Sat Oct 15, 2016 8:44 am
by ianpmarks
Dark Forces surely.

Re: Doom wasn't 3D!

Posted: Sat Oct 15, 2016 10:54 am
by DPrinny
You could look up and down in Duke

Re: Doom wasn't 3D!

Posted: Sat Oct 15, 2016 7:11 pm
by outdated_gamer
Well all 3D graphics are 2D in reality since you view them on a flat, 2D screen. :wink:

Doom used the so-called "ray casting" graphics technique that took a 2D map and presented it as if it was 3D. But this only went for the maps themselves as all the objects in the game were still flat 2D sprites that always faced the player's view.

Which 3D shooter engine was the first to do "true" texture mapped polygon 3D graphics is up for debate, but many would point to Interplay's Descent for being the first such as it allowed full 360 degree freedom of movement/viewing but it was surely Quake that took things to the next stage in those early times of non-accelerated 3D graphics (unill the rise of dedicated "3D accelerators" it was all about CPU software rendering on the PC).

Re: Doom wasn't 3D!

Posted: Sun Oct 16, 2016 7:03 pm
by Sokurah
So?
Yes, it looked 3D but wasn't really. Gameplay was good though, so who cares about the technicalities. Aren't we here because we love the old games despite their limitations?

Re: Doom wasn't 3D!

Posted: Sun Oct 16, 2016 10:21 pm
by Matt_B
I'd think of Doom as a restricted 3D engine rather than an entirely 2D one. Sure, for a lot of purposes the engine only considers things in two dimensions as that helps immensely when keeping the calculations simple, but objects still have a vertical position as evidenced by things like fireballs flying over your head, and the need to use stairs and lifts; and that, ladies and gentlemen, is the third dimension.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 7:13 am
by joefish
It's rather a juvenile argument; basing your argument on a very narrow interpretation of '2D' or '3D'. Or a complete lack of understanding of how the game engine and the rendering engine are not the same thing.

All the gameplay of Wolfenstein 3D takes place on one flat 2D plane, but the player's view is rendered using 3D algorithms to give it a sense of depth and perspective (even if shortcuts are taken with the rendering). But really, what's the point in trying to describe it solely as one or the other? If you render Pac Man with real-time 3D rendered objects or even an immersive VR first-person viewpoint, it doesn't change the game engine, but it certainly gives the player a different experience.

In Doom you could move up or down but the level design couldn't handle two levels in the same place, e.g. pass over and under the same bridge. Not looking up and down is a limitation of the rendering algorithm; it doesn't reflect where objects can actually exist in the game engine. But lots of games and simulators use a landscape map that only describes surface height at any one point; they can manage hills and mountains but not caves. Are these not 3D now? Anyway, if Doom let you move around on a 2D plane and go up and down to get over obstacles, how is that not three dimensions? Is the bit of the universe between my house and where I work not three dimensional, since it doesn't pass over and under the same bridge?

But in Duke Nukem 3D, because it was corridor-based, you could have two passageways that passed over each other, but you wouldn't be able to see one from the other; you could even create a MOD for it that had two passageways that doubled-back and occupy exactly the same space. How many dimensions does that make it? The argument doesn't really make sense.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 7:21 am
by shinymcshine
What about those games in the late 1980s that used the Freescape 3D engine - such as Driller, Total Eclipse and Castle Master on the C64 etc?

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 7:30 am
by joefish
shinymcshine wrote:What about those games in the late 1980s that used the Freescape 3D engine - such as Driller, Total Eclipse and Castle Master on the C64 etc?
They computed the environment as 3D space. In Driller you could actually switch to a hover-ship and go anywhere. The latter games put you on foot, but you could still go up, over and under objects in the game. It was all flat-shaded though. But then why not go back to Elite; that was entirely 3D and let you go anywhere, any way up you liked. There just wasn't a huge amount to see.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 7:37 am
by Antiriad2097
Jon Ritman went a little OTT with his code for Dimension Destructors in 1983, doing full floating point 3D calculations. With hindsight he realised he could have saved himself a lot of pain by using various shortcuts to achieve the same effect (look up tables etc), but it does make it technically interesting if we're hunting down a 'first' for 3D.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 10:29 am
by Treguard
MattyC64c wrote:This might be a bit late and some of you probably know this already, but Doom wasn't 3D. No, it was actually a 2D game, the 3D was just an illusion. Wolfenstien 3D wasn't 3D either nor was Duke Nukem 3D. The inability to look up and down wasn't a limitation of the engine's of these games, it was of course because they were all really just 2D games.

Which would mean that the first real 3D first person game engine would have been Quake, released in 1996!

https://www.youtube.com/watch?v=zb6Eo1D6VW8
No, YOU'RE not 3D!

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 12:38 pm
by joefish
His argument certainly lacks depth... :lol:

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 12:55 pm
by joefish
Where Wolfenstein and Doom cheat to save time in the rendering is that the perspective depth is only calculated using distance from the player in the horizontal plane; not vertically or diagonally upward. This is because if you do angle your view upward, you need to allow for how things high-up also appear further away when calculating perspective. And what were vertical lines up the walls around you now tend to slope away from you. Now if the textures on the walls have to be drawn tilted then you can't optimise your rendering engine around vertical lines any more.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 3:08 pm
by necronom
The Amiga version of Doom I used to play let you look up or down. I'm sure later mods of the PC version probably did, too.

Re: Doom wasn't 3D!

Posted: Mon Oct 17, 2016 3:41 pm
by the_hawk
Next you'll be saying Terror-Daktil actually in 4D!