Since there is no spring joint available, can I add another physics engine (JS) and start using?
Yes, you should be able to include another physics engine. There will be no integration with the editor, but you should have no problems using it with your code.
You can hook it into the main application update loop using the update event:
app.on("update", function (dt) {
physics.update(dt);
});
The PlayCanvas API doesn’t expose joints, but the internal physics engine (Ammo.js) supports them. For example, check out these games:
- Hungry Beast (src)
- Pipe Wars (src)
It’s kind of ‘naughty’ to use internal, non-API stuff in PlayCanvas, but it works. 