So, I'm looking at trying to create a rally racing game. Nothing serious at the moment, just looking at testing the viability of a few features I'd really like to see.
I'm looking for a physics engine that's already got a good start on simulating vehicle physics. Any thoughts? If it's a slick enough engine, I might even look at integrating it into JME, if it makes sense. 
Otherwise, I may have to start from scratch. 
-Falken
ever took a look at the Jbullet RayTrrace vehicle? (see there site there is a jnlp for it)
Well, it ain't bad for a start, but I'm looking for something a fair bit further up the realism spectrum.
For one, I'm looking to simulate a few things:
- As realistic tire-ground friction as possible. This means simulating tire softness, the actual contact surface area with EXTREMELY uneven surfaces, etc.
- loose-surface simulation. Varying tread-cut and tread depth will throw gravel, snow, and mud of varying densities and sizes all OVER the place in vastly different ways, which affects the direction the car travels as much or more than the actual contact of the tires with a rigid road surface. Not to mention the effect that the loose surface has of reducing traction with the actual road surface. Displacement of that loose surface should also be simulated, as it factors VERY heavily into strategy, not only for team drivers, but individual drivers, since the first driver of the day is going to be the one stuck driving over and thus clearing off the loose gravel, while later drivers will have mostly clear road to drive on, leading to faster times.
- Realistic suspension modeling and correct handling of weight shifting.
- Some concept of power transfer between the engine and tires in varying ways. Ideally, I'd like to define for each vehicle a torque curve and certain power-loss constants, (as well as gearing ratios) and have the tire motion modeled accordingly.
- Damage modeling - Not sure how extensive, but you shouldn't be able to bounce off rocks and drive away. This should include tire wear and puncturing.
- For controllers that support it, I'd LOVE to do some force-feedback modeling.
JUST to be clear, I understand this is a freakin' ton of work, and that there's not an engine out there that covers all these features without costing a pretty penny for licensing. I'm not necessarily looking to make a complete game, and if I am, I'm certainly willing to pay for the right engine powering it.
In the meantime, I'm looking for a good start to do some proof of concept work and test the viability of some ideas I have, such as random track generation, team / individual driver strategy, and some basic AI concepts I've been pondering. Not to mention some of the actual simulation stuff I've been toying with.
Again, not looking for a finished product, just an engine that can give me a good, solid starting point.
It's a tall order, I know, but better to start with somebody else's work than have to start from scratch.
-Falken
Well you coulduse the source engine, if you are not bound to jme
Vehicles. Non-player characters and, in a multiplayer game, other players can come along for a ride in cars that feature realistic suspensions with springs on each wheel and wheels that slip and skid depending on the surface material. Individually tunable parameters include horsepower, gearing, max speed, shift speed, tire material, tire friction, spring tension/dampening, and more. Leaning during acceleration, deceleration, and turning enhances the realism of the driving experience.