Zandronum

Reading a related topic around doomworld made me confuse, does the render is 2.5D or the map structure is 2.5D?

Well ... depends from how mappers made their maps , like as the format ( Hexen ecc . ) and which program they used .
Software render uses is 2.5D
Open GL one is based on ZDoom/GZDoom and actually supports 3D floors

So, if I made an udmf map it would be a 3D struct and not a 2.5D?
and Opengl is a 3D render not a 2.5D hmm

I thought 2.5D only applies to flat sprite as actors, and 3D environment?
Like, even without 3D floors the world is still 3D.
You can make 3D actors in OpenGL so you can't say Zandronum is 2.5D, period, from the other side most FPS engines would be able of having flat sprites (seen Doom mod on GMOD).

I am starting to dislike terms like "2.5D" because they are too ambiguous.

Doom has 3D Geometry: http://www.classicdoom.com/doommyth.htm#01

Let's just call it 2.75D and call it a day.

ibm5155 wrote: So, if I made an udmf map it would be a 3D struct and not a 2.5D?
and Opengl is a 3D render not a 2.5D hmm

What ?

The only changes you will get from a map format are the features.
Then zandronum will either render it in full 3D (Open GL) or in "2.5D" (Software) like you call it..

How can there be half a dimension?
It's like Z can only be applied when either X or Y have a value.

Literally speaking anyway.

I believe it could be classed as 3D as it's able to render X/Y/Z.
No matter if it's a hacked render or not.
Wolf3D on the other hand could be classed as 2D as everything in distance is actually scaled along X and Y.

Though, maybe Doom is the same, but I like to think as 3D because it has a Z factor since sectors can be edited in a X/Y/Z way.

The 3rd Dimension doesn't have to include the ability to stack multiple 3d objects over or under each other.

Just my opinion.

Doom is a 2D game with elements to make it 'feel' 3D.

(G)ZDoom has significantly extended those elements to the point where calling it fully 3D might as well be correct.

Since things aren't infinitely tall in ZDoom, it pretty much is 3D.
I mean sure, maps can't be fully 3D without a world of pain - but you still traverse a space that has width, breadth and height differences.