[ODE] Car handling - Overturning too easily

Nate W coding at natew.com
Mon Nov 11 11:30:02 2002

On Mon, 11 Nov 2002, Dominic Morris wrote:

> I'm sure that there must be a simple solution to this,
> so if anybody can advise me I'd be very grateful.
> I've got my car driving over my terrain mesh using the
> contrib tri-collider, and the one remaining problem I
> have is that when I steer the car when it's travelling
> quickly, it overturns much too easily.

I ran into this as well.  I've mostly just been tuning the tire-ground
friction, so it is more likely to slide sideways than flip onto its roof.  
You might also want to try lowering the car's center of gravity, either by
changing the chassis' inertial tensor or by reducing the 'ride height' of
the suspension.  

I think you have to expect a certain amount of rollover, since it's a
problem with real off-road racing as well.

Also, are you steering with a joystick, or are you using the keyboard?  
If the latter, you might want to try slowing down the steering response,
or reducing the steering angle as the car gains speed.

> Capped Cylinders don't seem any better, as they don't
> seem to fit the geometery of wheels any better than
> spheres, and I'm not sure of a user tri-collider for
> CCylinders.

I'm using spheres for driving over terrain, and flat-ended cylinders for
driving over ground planes.  I've been wondering if it might be useful to
have a "tire" collision hull - something similar to a cylinder but
simplified.  For example, just the ends of a flat-end cylinder, or just
the middle section of a capped cylinder (not the caps).  It might be more
trouble than it's worth, but then again it might be possible to save some
clock cycles by using a shape that is correct 99% of the time. 


Nate Waddoups
Redmond WA USA