You might remember Ontarget ( Store Closed )... Creators of WW2 Tanks boy these are mind-blowing , the artists figured out a way to make these Cata-pillars work like real , sure if you know the code no problem but the head that was behind it figuring it out !  Full respect ! Users would of said , that is just impossible as the Caterpillar are static built on the model , but it worked, the sad part of all this is that there are almost none left that are capable of such great Ideas and mind blowing effects what remains is sold Tanks with static Caterpillar and artists that might just say " Impossible to make it work "