Scale of things in Doom

Are there any specific guidelines for rendering real-life distances,heights and the scale of objects etc. in Doom's engine?

From my experiments I found that for what regards width, assuming 2 cm per map unit is a quite close guess (being the creators from the U.S., this could even be 2.54 cm or an inch per "pixel").

Considering how e.g. the player and former humans have a width (diameter?) of 20, that would be anything from 40-60 cm, which seems reasonable.

However, the same scale doesn't seem to hold up for height: being Doomguy 56 units tall, that means at least 3 cm/unit (or clearly more than an inch, if you prefer) unless Doomguy is a midget. This means that e.g. a height of 128 px is almost 4 meters.

I noticed that many times I got the scale of objects such as tables, sinks, toilets etc. totally wrong So, are there any unofficial or semi-official guidelines regarding the scale of stuff in Doom?

Scales are generally a bit screwed in Doom. It is common to use the Doomguy as the benchmark and assume that his 56 units equate to 6'. However, like all the Doom Humanoids, he is too wide for his height and his eyes are in his chest somewhere.

there's some info in this thread that I started when I was making another failed attempt at mapping. don't know how much it'll help, but there you go.

From Scott Ampoker's "metrics.txt" :

16 Horizontal Doom units = 1 horizontal foot
10 Vertical Doom units = 1 vertical foot

Also check out Jacob Berendes's "Real World to Doom" (realworld.txt) which has a lot more info.

Ajapted said:

From Scott Ampoker's "metrics.txt" :
16 Horizontal Doom units = 1 horizontal foot
10 Vertical Doom units = 1 vertical foot

That is good info, thanks, and I saw I was right-on with my initial guess, which I will render in metric for us smelly Europeans :-)

So: 16 Horizontal Doom Units = 1 foot = 30.48 cm = 1.905 cm per unit (just short of the 2 cm/unit I had guessed)

and

10 Vertical Doom units: 1 foot = 30.48 cm = 3.048 cm/unit, again almost right on the 3 cm/unit I had guessed.

So, case solved? :-D

Edit: on a side note, certain older "tips" I got like e.g. equating 32 or 64 horizontal units to 1 meter, were quite off scale, either too small or too large, and resulted in enormous or miniature objects. In metric, a 64*64 floor flat is practically 1.28 * 1.28 m or 1.6384 m^2, which is quite a big surface! If you wish to make a floor tile, that surface is enough for an array of 3x3 or even 4x4 "normal" tiles. It might be true that doomguy's speed and engine limitations alter scales a lot, but knowing how scales work helps making more realistic environments (well, to the point possible with doom, anyway).

On another matter....is there a limit in the map coordinates, like e.g. -32K to 32K in both x and y? How large can a doom level be?

On another matter....is there a limit in the map coordinates, like e.g. -32K to 32K in both x and y? How large can a doom level be?

The safe limit is actually a little short of (+/-)32k but it is due to DOOM using fixed point math for pretty much everything.

Some source ports may have removed this limitation though. For example, the Doomsday 1.9.x series uses floating point math for all map architecture and we are currently in the process of doing the same for the physics/collision systems (which is slow, boring work as we are trying not to impact on the gameplay nuances; read as implementing additional code to emulate bugs).

Maes said:

On another matter....is there a limit in the map coordinates, like e.g. -32K to 32K in both x and y? How large can a doom level be?

Another (more serious) limitation to what DaniJ mentioned is the BLOCKMAP lump. Depending on how many linedefs you have, the maximum size of the map is roughly 12000x12000. When the blockmap overflows, collision detection stops working properly.

This is an issue if you want to be compatible with the original DOOM.EXE. I think most of the source ports can build their own blockmap nowadays.

I remember making what 'looked like' a perfectly proportioned guy as a template sprite to work from when making new sprites. Only when i imported him into doom just to have a look he looked absurdly tall and thin, so i was going to re-do the sprite again, only ran into some difficulty with proportions. It doesnt help that all the humans in doom seem to be hunchbacks too... perhaps i should use the Imp as a guide, or just use the original sprite i made anyway, as the wad(s) i was gonna use it for are total(ish) conversions with no normal doom enemies, so with the player's size adjusted to be the same it wouldnt look so bad...

The thing you have to remember is that heights in Doom are 3/4 the distance as widths in Doom. To make a perfectly square-looking door in Doom, the height needs to be 75% of it's width. Using screen resolutions with a different ratio than 8:5 (such as 320 x 240 which is 4:3) will distort this making it look more squarish like intended.

Ajapted said:

From Scott Ampoker's "metrics.txt" :
16 Horizontal Doom units = 1 horizontal foot
10 Vertical Doom units = 1 vertical foot

That's acceptable, but makes most people only 170.69 cm / 5.6' tall, which is rather below average. Also, football pitches become too long (5512), and ten-story blocks, including groundfloor, become too tall (974) for Doom standards. Regarding the length, you might have lots of hassle with the LWE.

You forget that the Doomguy (and zombies) are VERY muscular, and I think he'd be taller than 1.70 cm. I think a "normal" person should look more like the civilians from Strife.

The only way of having a more or less accurate scale is using the shotgun when is held by the zombies.

Still as said I think DOOM has its own scale, things are bigger than what they look like from the players view. Just imagine how big the DOOM crates should be in real life.