UDMF compatibility between ports

Hi there, Doomworld people.

After asking in my last two threads about 3D stuff, I started wondering about some features in Eternity, like portals.

I've started working with UDMF. I don't know if this is correct, but I think it supports all ZDoom features, right? Now, in the wiki it's stated that in the (near?) future it (UDMF) will also be supported by Eternity. Now, I don't know if I'm understanding this correctly, but if a port supports a given map format (in this case, ZDoom supports UDMF), it supports all features available in that format, is that correct? Now, if Eternity becomes UDMF-friendly, will that mean that ZDoom will support Eternity features, and vice versa? For example, portals.

I have the feeling that something is wrong with my question, like if I was missing something. I mean, Eternity and ZDoom are two separate ports, with different objectives and strengts and weaknesses, different "architecture", etc., but I can't stop thinking that if they both (in the near future) support UDMF, I/we can do the same things with both, right?

Honestly, I'm a little confused about this. What do you think?

By the way, I've just started to experiment with portals in Eternity, so maybe that's an issue.

Another example: If I remember correctly, Doomsday (which is also expected to work with UDMF, according to the wiki), supports 3d models from Risen3D, and so does GZDoom (with small tweaks). Does this mean that Eternity will also support Risen3D models, like Doomsday?

Thanks for your replies, and good day.

Zed said:

Now, I don't know if I'm understanding this correctly, but if a port supports a given map format (in this case, ZDoom supports UDMF), it supports all features available in that format, is that correct?

Not necessarily. Map formats and feature sets are separate. For example, Boom uses Doom level format, even though it has a lot of new editing features.

UDMF has namespaces.

Since currently the only UDMF-compatible ports are ZDoom derivatives, the only really relevant namespace is the ZDoom one, which is where all the cool new ZDoom features are put. However, UDMF also has "vanilla" namespaces for Doom, Heretic, Hexen, and Strife. These do not have special features (the Doom namespace does have Boom features, others are vanilla feature sets).

At its core, UDMF is a limit-removing map format (you can easily have more than 65535 lines/sides/vertexes/sectors/things) which is easily extensible (adding new properties can be done indefinitely without having to change the format; compare with binary formats where we ran out of space for thing flags and linedef flags).

When Eternity will get UDMF support, it will include the ability to load maps in vanilla namespaces for all games it can run, and presumably an Eternity namespace.

The ZDoom namespace supports all features supported by ZDoom, regardless of game, but that is not necessarily the case. One could imagine an engine (let's call it BCDP, for Bob's Cool Doom Port) which would have a BCDPDoom namespace and a BCDPHeretic namespace because the feature sets aren't entirely shared between both games. However, it doesn't mean that ZDoom or Eternity would support the BCDP namespaces.

Finally, non-mapping features such as using models instead of sprites for monsters are out of the scope of UDMF.

So in short:
UDMF compliance does not mean full support of every feature of every UDMF port out there, the only requirement is support for the "vanilla" namespaces of the supported games. (If your port supports Doom and Heretic, you're expected to support the Doom and Heretic namespaces, but you don't need to support the Hexen and Strife namespaces since you won't load these games anyway, and you don't need to support the ZDoom namespace at all.)

UDMF is only about mapping features, and does not concern itself with non-mapping features.

UDMF confirmed for next Eternity release btw. However that probably won't be until well into next year.