jdoom - how faithful to vanilla doom?

It doesn't appear to support zdoom or boom features, apart from visplane etc. limits. Now, I've heard about other things that source ports have removed - such as projectiles not being blocked by trees. What has jdoom added/removed, gameplay-wise?

What has jdoom added/removed, gameplay-wise

Removed - nothing. jDoom can be configured to behave in the exact same way as the original DOOM.exe gameplay wise other than a few minor changes introduced by Lee K that are not currently optional in Doomsday 1.8.6 However, all of which can now be configured via a (BOOM-like) compatibility options menu in the upcoming 1.9.0-beta4

There are various new additions to the gameplay side of things that are optional though (such as jumping, free mouse look etc).

Currently jDoom does not support BOOM features. This is currently being worked on.

Visplane limit has been removed in the Doomsday Engine.

Several of the original DOOM.EXE limits (such as tiggered lines, moving planes, number of scrolling textures etc)are still in place in the current 1.8.6 though ALL have been removed in the upcoming 1.9.0

Although jDoom and the Doomsday Engine does not support ZDoom or BOOM features the same can be said about those ports with regard to Doomsday features.

I am particularly anal about changes to the gameplay mechanics in jDoom. If you find anything (gameplay-wise) in jDoom that is different from vanilla DOOM - I would like to hear about it so that I can make the necessary changes to provide an option to retain the original functionality. THE only exception to this rule is with regard to emulation of obscure bugs that compromise the integrity/stablity of the engine.

DaniJ said:

I am particularly anal about changes to the gameplay mechanics in jDoom. If you find anything (gameplay-wise) in jDoom that is different from vanilla DOOM - I would like to hear about it so that I can make the necessary changes to provide an option to retain the original functionality.

OK then. Can z-clipping be disabled (i.e. making it so that, e.g., you can't walk over the top of monsters' heads, or under cacodemons, etc.)? I haven't found such an option in 1.9.0 beta3.

It doesn't handle levels with a large number of voodoo dolls correctly. Example: caesar (it's in the archive).

OK then. Can z-clipping be disabled (i.e. making it so that, e.g., you can't walk over the top of monsters' heads, or under cacodemons, etc.)? I haven't found such an option in 1.9.0 beta3.

I thought that had already been implemented as an option? I'll check...

Yes it is "game-zclip 0" in the console.

It doesn't handle levels with a large number of voodoo dolls correctly. Example: caesar (it's in the archive).

Thanks for letting me know. What is the expected behaviour and what is jDoom's? (my DOS box isn't accessible atm so I can't check for myself just now).

Most other ports that support voodoo dolls feature the correct behaviour, so you can see in them.

The "real" player 1 start is at coordinates (-16, 208), and all the player 1 starts in the amphitheatre area are voodoo dolls. I'll take a wild guess and suggest that maybe the number of player starts of each type is limited to 128 in Doomsday, and so when the engine reaches the 128th, it makes that one the actual player.

I am particularly anal about changes to the gameplay mechanics in jDoom. If you find anything (gameplay-wise) in jDoom that is different from vanilla DOOM - I would like to hear about it so that I can make the necessary changes to provide an option to retain the original functionality. THE only exception to this rule is with regard to emulation of obscure bugs that compromise the integrity/stablity of the engine.

The chainsaw pulls you way further forward after a kill than it should. This is troublesome when you're hiding in a niche and plucking off pinkies one by one, because you can get pulled out and surrounded.

At least, that's my experience with jDoom 1.15.6, DoomsDay 1.8.6-beta2 on a Mac.

Most other ports that support voodoo dolls feature the correct behaviour, so you can see in them.

The "real" player 1 start is at coordinates (-16, 208), and all the player 1 starts in the amphitheatre area are voodoo dolls. I'll take a wild guess and suggest that maybe the number of player starts of each type is limited to 128 in Doomsday, and so when the engine reaches the 128th, it makes that one the actual player.

Ah so its a rather obvious one. Thanks I'll look into it.

The chainsaw pulls you way further forward after a kill than it should. This is troublesome when you're hiding in a niche and plucking off pinkies one by one, because you can get pulled out and surrounded.

At least, that's my experience with jDoom 1.15.6, DoomsDay 1.8.6-beta2 on a Mac.

Compared to DOOM.EXE? I'll investigate this also.

DaniJ said:

Ah so its a rather obvious one. Thanks I'll look into it.

Oh yes, there's no mistaking the difference.

Another wrong starting position occurs with Starship (a Hexen hub). You start the game in the wrong location (and one you can't escape from). As far as I know, this is nothing to do with voodoo dolls. The player starts in the correct position with Hexen.exe, Zdoom and Vavoom.

Another wrong starting position occurs with Starship (a Hexen hub). You start the game in the wrong location (and one you can't escape from). As far as I know, this is nothing to do with voodoo dolls. The player starts in the correct position with Hexen.exe, Zdoom and Vavoom.

Thanks again Grazza :)
Please do feel free to submit a bug report any time you find anything like this.

What a shame, my favourite port - models, textures (and mlook feels weird in zdoom compared to this), but no real features other than jumnping, mlook, limitation removals. Mlook in gzdoom feels a bit better, I look forward to getting models and textures being implemented in this port!

but no real features other than jumnping, mlook, limitation removals.

What the heck are you talking about? There are loads of features in jDoom/Doomsday besides those.

Just have a look for yourself (you don't want me to list them all do you??)

Mlook in gzdoom feels a bit better,

In what way?

DaniJ said:

What the heck are you talking about? There are loads of features in jDoom/Doomsday besides those.

Just have a look for yourself (you don't want me to list them all do you??)
In what way?

Better than zdoom - it's hard to impossible to set it right there, it's either too sluggish or too sensitive - in jdoom, you just set the one slider and you're right - probably because it leans more to the quake style of mlook - jdoom just feels more like newer FPS' with mlook, and more "natural".

The "real" player 1 start is at coordinates (-16, 208), and all the player 1 starts in the amphitheatre area are voodoo dolls. I'll take a wild guess and suggest that maybe the number of player starts of each type is limited to 128 in Doomsday, and so when the engine reaches the 128th, it makes that one the actual player.

Yep that was pretty much what was happening. I've removed the fixed limit (previously 100) and now playerstarts are allocated dyanmically. Fixed in SVN for 1.9.0-beta4

This fix didn't seem to help the other spawn bug in jHexen though (exhibited in Starship.wad). I'll have to keep digging.

The horizontal rocket jump in jdoom is not exacly working like the one in vanilla doom. ftp://archives.3dgamers.com/pub/idgames/levels/doom2/d-f/dgtc.zip
This level demonstrates that quite well.

DoomGater said:
The horizontal rocket jump in jdoom is not exacly working like the one in vanilla doom.

Thanks DoomGater. This issue is more troublesome to fix. I'll see what can be done.

DaniJ said:

The chainsaw pulls you way further forward after a kill than it should. This is troublesome when you're hiding in a niche and plucking off pinkies one by one, because you can get pulled out and surrounded.

At least, that's my experience with jDoom 1.15.6, DoomsDay 1.8.6-beta2 on a Mac.

Compared to DOOM.EXE? I'll investigate this also

Today I tried to play on Nightmare instead of Ultra Violence and came across a perfect example of this difference in action: On MAP01, try to kill the three imps up by the switch behind the secret door using the chainsaw. When I try, I actually end up getting pulled *through* one of the imps, and die because it gets in a few free hits from behind me.