Should we say that Doom is two-dimensional, two-and-a-half dimensional, or both?

[doomlayman]

I don't have any above-fundamental knowledge in computer graphics, physics or math so please excuse my ignorance or any false assumption.

 

I understand that Doom has both 2-D graphics and 2.5-D graphics.

 

• Its 2-D graphics I describe as the graphical user interface (GUI), first-person weapon sprites, floors, walls ceilings and boxes (and I guess in some sense, also "rooms" or "levels")
• Its 2.5-D graphics I describe as monster sprites, third-person doomguy sprites and some environmental objects

 

As the term 2.5-D subsets the term 2-D, I assume that it is correct to say that Doom is 2.5-D containing pure 2-D in it as well.
But in theory, someone can create a game which is either only 2-D, or, only 2.5-D, right? I mean, while I don't recall ever encountering a game which is only 2.5-D, in theory I assume that it's possible (what the gaming experience should even be like? Would it be horrible?)

 

So to sum up my question is, Should we say that Doom is two-dimensional, two-and-a-half dimensional, or both?

 

 

Edited May 29, 2023 by doomlayman

[Individualised]

It's three dimensional. This discussion is tired and boring.

[dasho]

[Trustanus]

Doom is far more than simply two-dimensional, but it is not limitless three-dimensional either.

[Wavy]

It's 3D with limits, end of story

[HavoX]

9 minutes ago, dasho said:

Hasn't this image been used to death already? :-P

 

Either way, it looks more 3D, but with sprites.

[Celestin]

Doom is a 3D game with certain limitations brought by the hardware capabilities of its era. I think the more interesting question would be where this whole "Doom is 2D/2.5D" claim came from.

[Trustanus]

7 minutes ago, Celestin said:

"Doom is 2D/2.5D" claim came from.

I remember it being used in the mid 90s primarily to explain the limitations of the engine, usually targeted towards teaching level design with the early level editors of the mid to late 90s. It was likely easier to explain it that way so people would understand they couldn't make rooms stacked on top of other rooms or have rooms directly under or above a staircase than to get super technical. That's my guess anyways. It also seemed to be used as a way to signal a difference between Doom and it's clones to the upcoming Quake, so it could've also been a bit of a way to hype Quake up.

Edited May 29, 2023 by Trustanus

[Catpho]

OP, just go read this:
 

 

[Edward850]

5 minutes ago, Celestin said:

I think the more interesting question would be where this whole "Doom is 2D/2.5D" claim came from. 

As best I can tell, the modern incarnation came from a Game Theorists video that made the most wild ass-pull assumptions about how the game worked (things like how height was an illusion relative to the camera, which ignored that multiplayer existed at all and projectile height clipping was an obvious observable thing), and given the relative popularity of the channel people just blindly accepted it as true. This spread far enough that even Digital Foundry accidentally repeated the same thing.

[Trustanus]

Doom being referred to as 2.5D is far older than YouTube videos. The videos just brought back these discussions more when they had long since been forgotten.

[Grain of Salt]

Fwiw I was around in the 90s and I don't remember doom, duke, heretic, rise of the triad or anything being referred to as 2.5D

[Biodegradable]

On 6/11/2020 at 7:02 PM, Biodegradable said:

Do people just get confused because it uses 2D sprites for the demons, power-ups, etc? I mean, it's so goddamn obvious you're walking around a 3D plane, for fuck's sake.

 

[dasho]

17 minutes ago, HavoX said:

Hasn't this image been used to death already? :-P

 

Either way, it looks more 3D, but with sprites.

 

It's in my saved attachments for a reason. I'll try to photoshop in something there for some variety.

[Trustanus]

10 minutes ago, Grain of Salt said:

Fwiw I was around in the 90s and I don't remember doom, duke, heretic, rise of the triad or anything being referred to as 2.5D

It was referred to as 2.5D (sometimes called extended 2D) in several editing books from back then as well as in magazine articles, and was more common when Quake's release was on the horizon. That is where I specifically remember the term being used as far back as the mid 90s to describe the engine limitations.

Edited May 29, 2023 by Trustanus

[Decay]

Doom sure is a game guys. Is Monopoly really 5D chess?

[Jayextee]

3D.

You can't have half a dimension.

[Andrea Rovenski]

i think doom is 4D, if anything, given that I started playing it just a few minutes ago and now the calendar says 2023? 

[Midway64]

It's limited, but still 3D.

Rather than explaining it I'm going to link this video:

 

 

[D0M0]

Quote

1 and a half D

- Sandy Petersen

[Klear]

Doom and every other video game is just a bunch of machine code that controls how pixels show up on your screen. Any dimensionality is illusory.

[Jayextee]

There are height checks on most things that aren't player/enemy/scenery objects, these probably just to cut down cycles on collision checks so DOOM would run better on the average PC of 1993. Ergo, limited (or, my preferred term is 'selective') 3D about describes it. Really, try running under the fireballs from the imps on the high ledge in E1M1, it's completely possible.

 

People who are still parroting the 'DOOM is really 2D' lie in 2023 deserve unusual and excruciating forms of punishment.

[Redneckerz]

 

@doomlayman This has been discussed to death and the fact that this is your first post since March 18 tells me you may have seen the previous topics, such as this March 22 one as a lurker and figured, why not have another one.

 

More threads just like yours? Here is a search engine!

[boris]

It's inter-dimensional. From the manual:

 

Quote

For the last four years the military, UAC's biggest supplier, has used the remote facilities on Phobos and Deimos to conduct vvarios secret projects, including research on inter-dimensional space travel.

 

[Darkcrafter07]

Limited but still 3D and let the game release year not confuse you, some shortcuts were made to enhance performance, like you can't run below or above enemies but projectiles can pass below or above no problem.

 

What's about 2D map layouts? They are only 2D when stored but as soon as the game starts the engine unfolds it into a 3D space.

 

As soon as source ports appeared, these shortcuts were easily cut off in two or three mouse clicks from the source codes and new features added:
 

- 3D floors: allows to create platforms hovering in space (they are actual geometry, consisting of their own floor and ceiling values + a middle texture around them);

 

- portals: stacked or wall portals, these guys allow Doom to go even further than just 3D, like building non-euclidian geometry and 4D, geometries not possible (or who knows) in our 3D world.

Edited May 29, 2023 by Darkcrafter07

[AbeAwesome]

DOOM is actually 4D—you can time-travel using the demo recording/playback feature. And also, as you play, time moves forward in increments of 1/35th of a second every frame. :)

 

Also, the world it readers is three dimensional, whoever says otherwise is uneducated, and likely immoral (why immoral? no idea, it just feels right).

[doomlayman]

39 minutes ago, Jayextee said:

3D.

You can't have half a dimension.

 

Interesting answer :)

[Zulk RS]

Honestly I still think Doom is not 3D with Limitations but 2D with extra additions (i.e the height checks on projectiles) and presentation.

 

Sourceports that allow room-over-room shenanigans make Doom really 3D though.

Edited May 29, 2023 by Zulk RS

[Pechudin]

String theorists say reality is 26-dimensional, so DooM also must be, but it is projected to our 3D space because our puny brains cannot comprehend it.

 

Something something Carmack.

[OpenRift]

It's 2.5D. The proof is in Heretic, which uses the same engine. You look up and down in vanilla Heretic you'll notice the Y-shearing almost immediately. True 3D engines don't do that. The whole "3D with limits" thing is kind of silly because it inadvertently describes what 2.5D is. It's pseudo-3D. I really don't know why people keep asking this, because if you've played enough pre-Quake "3D" games, you'll notice the telltale signs of pseudo-3D almost immediately.