After playing some (sadly rather bad) tank game I also wanted to implement a tank in Newton and thought about how doing that. Recrating the tracks piece by piece was something I did some months ago but it was neither very great to drive nor was it's performance acceptable. Raycasting would be an alternative, but I like to try out things others haven't already done. So I sat down and then I thought : Hey, basically tank tracks are nothing else than "inverted" conveyor belts. Instead of being static and transporting stuff it moves itself and some attached body.
So I used an old model of a JagdPanther I modelled last year (for learning purposes, it's a rather easy to model WWII-tank) and plugged it onto a landscape. The tracks come from a separate mesh and I applied a special material to them that has a callback where I do almost the same stuff as Walaber with the material callback for his conveyor-demo (it's also here in the showcase, just search for it). And after some testing and tuning and trying I finally got it to work and I must say that it feels nice, even better than the tank of the so-called realistic tank-simulation I played today (which gave me the impulse to create the tank demo). So it's again just impressive what one can do with Newton's material system.
Here is a screenshot (clicky) :
And since a static picture is totally boring and videos are very common here, you can download a video of the tank in action here (~1min20secs, 5 MBytes, WMV-format).
It's a bit late here (almost falling asleep), so I haven't had the time to finish it up (not 100% content with it) and upload the demo. But I think I'll be able to upload it within the next 2 or 3 days, so you can see yourself what Newton's material system can do. It's not only impressive that such a thing is possible with materials, it's even more impressive at how easy this is. The callback for the tracks is only ~10 lines long and there is no single line of higher mathematics in it. Although this isn't the perfect solution for a super-realistic tank-simulator it's nothing short of how other current games implement tanks (at least I haven't seen a game where the track bends realistic on the terrain).