Vehicle setup

[mcan]

Hello. I'm a little new to this. And I don't really understand what the different vehicle dynamics represent.
For example, I'm simulating a vehicle with the following preferences: weight 1900kg, length 4m, height 1.4m width 2m, wheelsize 0.7x0.5m (so a more or less usual car).

Concerning the wheel, what is the following and what could be a good default value:
suspensionRestLength
suspencionStiffness (N or kg?)
wheelsDampingRelaxation (N or kg?)
wheelsDampingCompression (N or m?)
friction (does this have the same physical value as a standard tyre (about 0.6)?)
rollInfluence

Concerning the others:
engineForce (what represents 100 and 400bhp?)
breakForce (how much? and is this kg or N?)

Thanks //Markus

[mcan]

Or at least maybe someone can point out where I can read it myself. I have looked in the doxygen doc. But there is not a lot of explanatory text there...

/Markus

[mandor]

Hi

You should start with the values in the example and tune it until the behavior suits your need. In my experience, the parameters are not enough "physics-like" to be defined only using the specs of the real vehicle.

Best regards,

[Verbo]

Hi,

I second the question: what are the units of engine force in btRaycastVehicle::applyEngineForce() ? Is it TORQUE or HP ?

Thanks.

Verbo

[frca]

I think it's in Newtons (by default).

[frca]

I have a related question: What has better simulation quality, forthcoming btGeneric6DofSpringConstraint, or btRaycastVehicle suspension when talking about spring model (I know that suspension implementation has more parameters, but anyway)? Or is it the same?
Thanks