   Truck Trailer Physics
  I need to program a truck with a trailer for a project I am working on.  At this point I only need to think of the problem in 2-dimensions.  I am thinking that it should be simple but can't get my head grasped around it.  It should be similar to a caterpillar type movement except easier since you would only be worrying about 1 link.Does anyone have any ideas how I should go about doing this or have any code examples/links they could share?  I did a search and really couldn't find anything.   
  It depends on what kind of constraints you have.  Can you use an external physics library, or must you roll your own?  If you're rolling your own, it can't get any easier than simple using a hinge joint between a base vehicle and a secondary vehicle for the actual trailer (but it can get a lot more complicated [wink]).  If you are allowed to use an external physics engine, Newton has a great example of truck trailer physics:http://www.newtondynamics.com/forum/viewtopic.php?f=14&t=4498;  On a semi-related note, have you seen Rigs of Rods? This simulation has very nice, realistic-looking real-time simulations of trucks with trailers.   