Jumping, step size, look up/down etc...

I'm having some trouble making up my mind here.

ZDoom supports jumping, look/aim up/down etc, and so do some other source ports. Fine, having practiced 3D deathmatch in Quake III Arena some, I kind of like it, and it's not particularly hard to control with keyboard + mouse. (I used to hate games that required aim up/down before I switched to mouse control...)

Now, the problem is that if I design maps for the ZDoom engine (even without actually using any extra features; just allowing jumping and look up/down), the maps won't work well with Doom, and possibly not with source ports other than ZDoom. I can live with requiring a source port, but I'd rather *not* rely on a single, specific branch.

Any ideas for making "portable" WADs, short of disabling all non-Doom features...? Map design ideas that make maps work well, if yet slightly differently, in original Doow, and ports?

I'm talking about dealing with problems like being able to just jump into secret areas in ZDoom, but having to figure out how to open a door in original Doom. I don't like setting "unmotivated" impassable flags all over the place, just to keep port users in line... There has to be a point in jumping, or the feature might as well be disabled! I also like appearance/function consistency accross the entire game - anything else is usually just annoying, and looks stupid, IMHO.

Is there some kind of solution, or do I just treat different ports as different games, requiring different map versions?


Now for some lower level stuff:

Which features are available in virtually all "extended" source ports, and how compatible are they? Do all ports jump equally high? Do all ports with jumping allow walking up a "step" (24 units) while in the air, like ZDoom does? Look up/down limits? Is the player *exactly* the same height and width in all ports? Does rocket jumping work the same on all ports? Which ports support walk over/under enemies/other players? Is there a scripting language that's supported by more than one port? Are there any non-Doom linedef types that are available in most ports?

Is there a feature comparison list somewhere, containing some of this information?

Another question: Is it safe to assume that most engines will ignore information that they don't understand? (That is, if I use some ZDoom linedef types in a WAD, will Doom 1.9 or whatever crash or otherwise freak out, or just treat them as "normal" linedefs? Likewise for lumps of new kinds?)

You basically have two options, design for plain Doom or pick a source port and design for that engine. I believe the majority of people use a source port, although I know a few folks still use Doom95.

ZDoom appears to be the most widely used port, then Edge and finally Legacy (by looking at the released maps), then Boom (PRBoom) and MBF. The engine you choose depends on what you want to do with your map.

If you choose plain Doom, the map can be played with any source port and this is the only way to create a truly portable wad. (There is no way to make a wad for one engine and have it run successfully on another engine). If you keep the linedef count down, it can be played on the original Doom. However, most maps are highly detailed so even a map that only uses the basic Doom constructs requires a port with enhanced linedef support.

If you want a source port that has some good features but is closest to the original Doom in playing, than use Boom (PRBoom is the windows version) or MBF. Boom is the orignal source port and most later ports support the Boom extensions (except for Edge I think).

ZDoom offers a host of advanced features and has a powerful and flexible scripting engine. If you want to create a level with a lot of player interaction, ZDoom would be a good choice. ZDoom is also the most popular multi-player engine as well. The ZDoom based SkullTag is the de facto standard in ZDoom multi-play.

Edge offers DDF, a powerful replacement for Dehacked (an EXE hacking model). Edge also has true 3D floors and a limited scripting engine called RTS. If you want to create a heavily modifed game (a TC or PC) or you want an engine that uses true 3D, Edge is the way to go.

I don't use Legacy but I do know it has some pretty good features including 3D floors.

I have written maps for plain Doom, ZDoom and Edge depending on the play experience I wanted to achieve. Decide what kind of map you want to create and then choose an engine that best supports that goal.

To answer your specific questions:

1) Wads are not portable. If you use linedef types from one engine on another, crashing, errors and strnage things may happen. You'll have to pick an engine or stick with original Doom. Most ports use Boom extensions, but differently, so that is not a real common factor.

2) Most engines will ignore lumps it doesn't know about.

3) I'm not sure about jumping, but the step height, player height, monster height are all the same for all ports. These can be changed of course, but since mosy ports can play normal Doom maps they support the standard game metrics.

4) Most ports allow walking over under objects. Original Doom does not. (Original Doom has no concept of height.)

5) Each port has its own scripting language, if it has one at all. ZDoom and Edge have scripting. ZDoom has the most advanced system called ACS and is from the Hexen sources (the good folks at Raven).

6) Again, there is no real common implementation among ports. Most engines use some sort of Boom extensions, but if you stick with Boom it may not work on all ports.

7) For the differnt ports hit the Doomworld Source Port section and visit the different web pages of the ports. You should also download each one and try it and see which one you like to play.

8) Again, if you use unsupported linedef/sector/thing types in a port it will probably crash or behave strangely. It may not, but so far it has been my experience that the engine will.

Keep in mind that if you use ZDoom in its native mode, it uses the Hexen wad structure. The Hexen wad structure is an extension of the Doom wad structure to support the extended feature set. If you try to use a ZDoom wad with any other port or plain Doom (except SkullTag), it will really puke.

I should add, the ZDoom will run a standard Doom wad that has the Boom extensions. However, you won't be able to have scripting or the ZDoom specific features. Most, it not all, ZDoom maps use the native ZDoom (Hexen) mode.

Thanks for the info! :-)

Looks like ZDoom would be my choice for now, most importantly because it's very popular. (That is in itself a form of portability solution, as ZDoom at least runs on Win32 and my plotform of choice, Linux.) Further, it seems to do everything I currently need (if I want *real* 3D gameplay and high quality rendering, I'll use Quake II or Quake III, but it's not worth the effort unless I'm really going to make use of the extra power, IMHO), and because it's well suited for multiplayer, which is my primary interest right now. Of course, being a programmer since the age of 10, the scripting system also looks interesting. I'll use ZDoom's native WAD format, of course, as it doesn't really seem motivated to stick to the original Doom format.

Makes sense?

Just do what I'm doing. Make it for the normal doom first, then go back over it adding in slight changes and fixes for Zdoom or other source ports and put those modified levels in a new wad. Now you got it woking for both in not so much time.