Since August 2009 I've been working on a mod for JKA which attempts to include a physics engine into the game. As all of you will know, JKA lacks a proper physics engine, and personally I think physics can add an extra depth to gameplay if it's used in the right way.
Some of you might have already seen the demo videos I've uploaded on to YouTube. I've not publicly mentioned this until now, because I felt I wouldn't be showing anything new - Stalax has already shown some attempt at incorporating a physics engine into JKA, but development on this has stopped. I've recently got a working version of something that Stalax (to my knowledge) didn't have implemented. JAPhys uses the same physics engine as the one that Stalax used, which is Newton Game Dynamics.
Here's three videos of what is somewhat completed, but bear in mind everything is still WIP so these are likely to change their behaviour (for the better).
And finally, here is the new feature which Stalax did not have: buoyancy in water. Sorry about the lighting, but I didn't have a lot of time to make the map look better like the one in the first two videos
If you're wondering, the numbers on the boxes show the mass of the boxes. I will be adding support to spawn models as physics objects instead of plane boxes, but for testing purposes, boxes are the easiest to get working, and once I've completed a fair few things I have planned, then I'll think about adding models as physics objects.
Stay tuned for (likely to be slow but stunning) updates!
For the developers:
This mod is currently open source. You can find my project page here: japhys - Project Hosting on Google Code. Currently (25th January 2010), the code is really quite out of date but what's in there is working. Please note that I will not answer any questions regarding the source code. The code is there for people who know how to use it, and/or can solve the problems themselves. I will, however, explain how the physics engine is used by the game.
Questions I know people will ask:
Will you be adding cloth physics?
Possibly, possibly not. If I can work out a reasonable way of adding it, and without too much hassle to modelers, then maybe.
Will you be adding ragdoll physics?
This is something I want to add, so hopefully it will make it into the mod. If I do add it, it will more likely to be later rather than sooner.
Where can I download it?
Nowhere as of yet. It's not finished yet.
When will it be released?
As with all good things, "When it's done".
Will it support Mac?
Question is, "will it support Linux and Mac?"
Hopefully, yes. The physics engine I'm using has implementations for Windows, Linux, and Mac so as long as I have access to all three OSs then I can. Unfortunately, I don't have access to a Mac! So I'm hoping someone will be able to help me out there.
Why haven't JKGalaxies added physics if it's so easy to do it?
First of all, doing this is no easy task. I've spent the past few months implementing what I consider a small portion of a full physics implementation. Having spoken to BobaFett of the JKG team, he's told me that the team doesn't feel it's worth the time and effort to implement something which they don't think will add to the gameplay they are after. My 2 cents on to the end of this, is, adding a physics engine is only worthwhile if it's fully implemented. Not doing so will create inconsistencies and this is bad for any mod I think.
Will this be for single player too?
No. This modification is entirely code-based, which is impossible for single player mode. It is available for multiplayer only.