Romero tweets that Doom is 3D.

2 hours ago, DSC said:

Man, who would have thought I would encounter and even speak to (Doomkid) long after that...

It's good to know someone, somewhere out there, actually considered their interactions with me to be a positive experience!

9 hours ago, DoomGater said:

Doom is 2D. Otherwise it could not be played on a FLATscreen. right??

The argument is over - DoomGater wins.

Hold up, people think the game is 2D? 

3 hours ago, DarnedEnd57 said:

Hold up, people think the game is 2D? 

Hold up, people think the earth is flat? 

9 hours ago, SYS said:

Hold up, people think the earth is flat? 

I didn't want to cause a fuss, but now that you mention it...

5 hours ago, dr_st said:

I didn't want to cause a fuss, but now that you mention it...

15 hours ago, dr_st said:

I didn't want to cause a fuss, but now that you mention it...

I think that must be a joke. 

Or maybe it's a sect. 

In Russian one day RENTV said about flat earth. 

2 hours ago, Taw Tu'lki said:

I think that must be a joke. 

That's what a friend of mine thought when I had discovered its existence and shared with him a few years back. He wouldn't believe people who genuinely think this could exist. Then he proceeded to join the forums and troll them for some time (they would temp-ban him occasionally). To be honest I think that quite a few of the people there who actually pretend to support the theory are trolls as well.

2 hours ago, Taw Tu'lki said:

In Russian one day RENTV said about flat earth. 

RENTV wouldn't have been RENTV if they had allowed such a juicy scientific discovery to slip.

On 6/11/2020 at 4:55 AM, SuperchargedEuthanasiaDiv said:

Doom is 1D. You don't call it DDoom, DDↃoom or DDDoom, do you?

DooD > Doom

On 6/11/2020 at 9:22 AM, Taw Tu'lki said:

Half-truth.

Because DOOM at first side is 3D. But actually, it's a 2.5D. Because it has a 2d sprites.

The first 3D shooter is Quake.

It's a shame that the developer of DOOM knows little.
 

Particle systems in modern 3D engines are using 2d billboards for the particles. Does it make the engines 2.5D?

If I combine somehow 3d models for enemies in the rest of the Doom engine as it is, will it suddenly make it 3D?

On 6/11/2020 at 6:09 PM, SaladBadger said:

There are some fundamental bits of game logic where 2D is a bit of an afterthought, like projectile firing, where the projectile is aimed as if it was a 2D game, and then enough vertical speed is added to make it so the projectile will get to the right Z position when it gets to the right XY position 

I don't understand this argument though. In modern 3D engines when you want to interpolate projectile position on 3D space, you will add each coordinate separately. Each speed component will add to it's own axis, so saying vertical speed is added is no different than the X,Y speed added to the rest. That wouldn't make it lesser than 3D.

My post was more about the logic Doom using being "2D" that was crudely extended to "3D." My understanding is that a straightforward projectile in a newer game engine would solve every axis at once. Something like take the vector to the target in XYZ, normalize it, and use that to set the velocity by scaling it to the desired velocity. All of this is done at once and the projectile will move at an entirely constant speed no matter what angle it was fired at.

Doom, on the other hand, only does this in 2D. Essentially it creates a vector facing the target in the XY plane, scales that to the desired speed, and sets that as the velocity. It then compares the Z distance from the start spot to the target's, and adds enough velocity to make it so that when the projectile would arrive at the XY plane, it will also have reached the desired Z distance. This means a projectile being fired with a greater pitch will move faster, and it can move at excessive speed if the Z distance is great, and they also can't be fired straight up and down.

It doesn't really imply much about the game's 3Dness or 2Dness, since again, you can do this same exact thing in any modern engine, but it does suggest that within the game logic interactions on the Z axis were a bit of an afterthought.

would Romero consider Wolfenstein 3D 2D or 3D? The title makes the question confusing. the question is confusing. I'm confused. what?

25 minutes ago, LiT_gam3r said:

would Romero consider Wolfenstein 3D 2D or 3D? The title makes the question confusing. the question is confusing. I'm confused. what?

Castle Wolfenstein was 2D, so....

37 minutes ago, LiT_gam3r said:

would Romero consider Wolfenstein 3D 2D or 3D? The title makes the question confusing. the question is confusing. I'm confused. what?

If an enemy has to die and fall down for you to pass through would you consider that 3D?

23 minutes ago, unerxai said:

If an enemy has to die and fall down for you to pass through would you consider that 3D?

I wouldn't not consider it. How would that be a deciding factor? wouldn't it just mean that the sprite has changed to a new code? I really am not good with coding terms, but I did take a camp for it. 

On 6/11/2020 at 10:29 AM, Mr. Freeze said:

 

One of the first. The first true-3D shooter is Descent, released in 1995. 

*cough* Midwinter 1989 *cough* TBH, there are plenty of true 3d shooters from the 80:ies. There's not really much to be gained by chasing "the first" or you go down a rabbit hole of "firsts" as can be seen in this video where they try to find the first video game.

6 minutes ago, LiT_gam3r said:

wouldn't it just mean that the sprite has changed to a new code?

Sure. Strictly speaking it just means the game decides the sprite is no longer an obstacle, but in terms of in-game visual representation, it could be seen as 3D.

Dooms engine is 3d much in the same way as Zelda a link to the past is 3d. 

Wikipedia, the greatest and most reliable website says this on the DOOM (1993) page. 

Quote

 It pioneered online distribution and technologies including 3D graphics, networked multiplayer gaming, and support for custom modifications via packaged files (WADs).

even the online encyclopedia states that the game utilizes 3D graphics. You can't argue with the most respected source in all of the world.

although, later it does have a picture of this. 

Still, I would believe it was 3D. 

Someone else already said it but the whole argument is predicated on where you draw the the line at what 3D means. I could say no game is 3D until full on holodeck games exist. I wouldn’t be wrong from certain perspectives. 2.5D is a meaningless cutesy term to define Doom in the context of the time period between Wolf and Quake, not some immutable statement of mathematical or computational reality.

On 6/11/2020 at 7:17 AM, TheMightyHeracross said:

"2.5 D" isn't a real thing. You can't have "half" of a dimension.

 

That's an issue of semantics. You're technically correct, but meaning isn't always literal and common usage isn't always built on technicalities. The term "2.5D" refers to games with 3D environments in which movement is restricted. It's a pretty niche term and I don't find it to be particularly useful, but I think Klonoa: Door to Phantomile is a good example (as someone posted the relevant old Caddicarus clip). The environment is three-dimensional, and said environment curves and wraps around in a way that gives the movement dimension, but your direct control is restricted to left and right movement. It's not really 2D, but it's not 3D either, hence "2.5D." It's convenient shorthand that efficiently communicates the point and because of that I would consider the term accurate, even if it isn't necessarily true from an objective, technical perspective. 

^{(It's only after I post that I realize that I'm like two weeks late to this and I apologize for bringing you back into it if you didn't want to be)}

^{(And it's only after my first edit that I realize that this point has already been made and so I'm just being redundant)}

Look man, when Lord Romero says something is 3D, 

IT.

FUCKIN.

IS

Could we call it a 3D game with some limitaions, like the thing that there cannot be a room above another one?

You are moving in all directions, like in a 3D space and everything is rendered differently depenting on your position and view point. Also, projectiles take into consideration your height so they can pass over or below you without hitting you and so on.

I think 2.5D is used for games that are actually 3D, with polygonal models for characters and environments, but play like a 2D game, ie you can move only left or right, etc.

1 minute ago, Lokatzis 007 CJ said:

I think 2.5D is used for games that are actually 3D, with polygonal models for characters and environments, but play like a 2D game, ie you can move only left or right, etc.

Well, if that's so, where are the up/down controls in Doom itself? You have no meaningful control over your altitude most of the time, except when falling off a ledge (then you are indeed manipulating your z-coordinate, even though it's just gravity pulling you down). In that sense, Doom plays exactly like most vehicle/tank sims. Doomguy (not Doom as a whole) is not very different than a conventional land vehicle with two degrees of freedom (DOF) in movement, and 3 DOF in the controls (forward/backwards, yawing left/right, and, unusually, strafing). He can move to any (2D) point of the map, except those prohibited by the map's geometry and actor dimensions, and changing altitude is not allowed directly, but only when using stairs or falling off ledges (OK, maybe archvile jumps too). So you could say you have 3.5 DOF in the controls, but you can only really reach points defined on a 2D map (2 DOF), you cannot e.g. fly to specific height and stay there ;-)

Granted, two additional (up/down controls) were present in Heretic, which is the exact same engine, so the control DOFs now reach 4 and reaching any arbitrary point in 3D space is now possible, so you finally have 3 DOF in movement.You still cannot (properly) pitch up/down or roll like in Descent though (6 DOF in movement).

46 minutes ago, Maes said:

Granted, two additional (up/down)  controls were present in Heretic

Those are only for looking. Don't be silly. Hexen did add jumping, which would make for that extra degree of freedom, though. However, we will strictly talk about the Doom engine, and limit-removing ports. Heretic and Hexen are different beasts, with their own modifications of the source code, which therefore does not count as the Doom engine for our intents and purposes... and we're not discussing about whether Hexetic is 3D, 'aight?

In its core, Doom does not know whether it is 2D or 3D either. X and Y coordinates are extremely important, as map design is limited by its own intrinsic technicalities to a 2D plane, with only a few gimmicks to try and alleviate the issue. Usually, good Doom maps feel 3D, they feel like a place you could actually be in, and climb a stepladder up and lick the ceiling like there was an actual, solid ceiling there. (Not advisable for certain flesh ceilings, though!) You also can not place enemies in different vertical positions, as the Z (vertical) coordinate of their location is always determined by the engine itself, almost always just pegged to the floor.

Those sorts of limitations might not seem like much, as they're mostly a map format thing and not necessarily an engine thing, but they are pretty big, considering the initial state of the engine is the map. I mean, Sunlust wouldn't be Sunlust if vertices were jittered here and there and 75% or so of the enemies were randomly discarded during map load. They are also the most obvious things that come to mind when discussing the Doom engine with the current regards.

Now on to the big guns.

The level geometry that is rendered, which is the largest occupied real estate in the screen 99% of the time, is raycasted. It is supposed to simulate the perception of height and depth, but that is flawed, as it does not apply actual perspective. You can verify this by looking up/down in Heretic! Or also in Duke Nukem 3D; Build too had this issue, despite its overall technological superiority otherwise.

The actual space of the game is 3D, in terms of movements in the broad sense. Doomguy can fall, he does not snap to the floor instantly when he falls off a ledge. The objects look two-dimensional, but that is only a side effect of using sprites for object graphics. Even though you can't jump in Doom, you still occupy space vertically, and you can't walk into tunnels too short, or corridors with ceilings too low. You can't even crouch, dangit!

The physics engine, which I think is what mostly separates a 3D game from a 2D topdown/sidescroller, is handicapped. Most objects only need to encroach in the horizontal topdown plane to collide, as there is no height check for most collisions, effectively rendering most solid objects impassable at any height (hence "infinitely tall"). There are exceptions for projectiles, but those are the exception, not the rule. Interestingly, though, hitscan attacks are not affected by this. I imagine this was mostly a way to save CPU cycles back in the days of 486, but it becomes apparent quickly if you've ever tried to throw the secret shotgun area switch in Doom II MAP01. Good luck getting out whilst brownie fuckers with catlike scratching abilities damn Imps await you downlift.

So, in terms of map geometry, Doom is 2D. Objects themselves are mostly 3D. Sectors do have height values attached to them, but they are more like metadata attached to two-dimensional polygons. The engine itself is mostly 3D, and the "metadata" helps here not only with drawing horizontal planes (floors and ceilings), but also with determining the bounds of an actor's vertical position (such as gravity or headroom).

53 minutes ago, Gustavo6046 said:

 

Those are only for looking. Don't be silly.

So are you telling me, I have been living in a lie?

And Heretic is so ridiculously close to Doom in engine terms (v1.1, of all things), went that extra mile (well, more like extra 10 yards) in terms of controls that would unambiguously shut down most "is X 3D?" debates, and yet it's like the proverbial elephant in the room, ignored/dismissed.

Doom/Heretic maps however can be thought of as the extrusion of two 3D surfaces (one for floors, one for ceilings). Just like a simple surface plot is but a simplified case of 3D (you cannot have two independently defined points with the same XY coords), adding another surface just gives, well, just another point. It's not like a full 3D mesh. Room-over-Room extensions can be thought as adding more surfaces to the mix but, again, it's a case of "close but no cigar".

Maes, what the fuck? How could you post a link to that wretched place?!

Here's the real link: https://doomwiki.org/wiki/Wings_of_Wrath

On 6/27/2020 at 3:31 PM, SaladBadger said:

Doom, on the other hand, only does this in 2D. Essentially it creates a vector facing the target in the XY plane, scales that to the desired speed, and sets that as the velocity. It then compares the Z distance from the start spot to the target's, and adds enough velocity to make it so that when the projectile would arrive at the XY plane, it will also have reached the desired Z distance. This means a projectile being fired with a greater pitch will move faster, and it can move at excessive speed if the Z distance is great, and they also can't be fired straight up and down.

It does makes sense now, thanks.

Actually, I never noticed before that firing projectile vertically will move at greater speed as it interpolates a shorter distance in XY. I need to try this on actual Doom, maybe not with mouselook in modern ports, but with some lucky autoaim on classic doom engine. It might be hard to see.

17 hours ago, LiT_gam3r said:

would Romero consider Wolfenstein 3D 2D or 3D? The title makes the question confusing. the question is confusing. I'm confused. what?

I thought about Wolfenstein and technically it's more 2D than 3D. The map is simply a 2D bitmap. Nothing has a height, gameplay doesn't make a sense to even shoot on vertical axis as there are no things above/below ledges, etc. So, while some arguments on Doom being 3D is that both the data alone are enough to extract 3D information and the gameplay projectiles etc are moving in 3 axes, that's not the case for Wolfenstein 3D (the map doesn't contain the height of the walls, it's a 2d bitmap,. the gameplay doesn't make sense in the 3rd axis).

But here is the kicker. Back in the days you would be crazy to describe Wolfenstein as 2D. The marketing would call it 3D. The developers would code it 3D. The press would call it 3D. Why? Because it couldn't fit the 2D, it was a quite different things than Super Mario Bros,. it was looking the world through first person and navigating, even if the navigation was restricted. All these new engines, regardless the techniques behind them, would be easily called 3D. And there wasn't a scientific notion which said "A game to be 3D must have this and that". But of course you can talk whether specific elements are 2D or 3D. Only later when regular 3D polygon engines became the norm, people wanted to re-categorize things and since 2D didn't made sense, they ended up with the 2.5D.

The question whether it's 3D is very superficial. The most accurate thing is to describe in detail the engine and data structure of the maps, things, etc. But that wouldn't give a short answer which most would like. It's the same as the discussion whether this console is 16bit, 32bit or 64bit and whether that makes it more powerful. You have to discuss a lot of details and bottlenecks of the hardware and then this doesn't give an easy to consume and repeat answer.

On 6/11/2020 at 4:55 AM, SuperchargedEuthanasiaDiv said:

Doom is 1D. You don't call it DDoom, DDↃoom or DDDoom, do you?

Incorrect. Calling it Doom requires two dimensions.

The proper name for the game is ――――.