[ODE] Problem with rolling sphere...

[Mal]

James Myers wrote...

>I tried several variations, then one that works best
>for me is to add a force of about
>-(.08*dBodyGetLinearVelocity) per tick, but the
>spheres tend to roll somewhat off course as they slow down.


This would be either linear drag or angular drag, and can be used to
simulate bodies being in denser atmospheres ( like water )...  this
might be a useful feature to integrate into the core engine if it
doesn't already exist.

Nguyen Binh wrote...

> To make it more reasonable, we have to add rolling friction. But I
> can't see any physics engine implement it. (Even Havok???)


Another useful type of friction ( Blender had it ) is anisotropic
friction, where friction can be adjusted on the various axis of each of
the physics objects.  This allowed the spherical object in blender to
act like a wheel ( friction along the front axis was nearly 0, but at
the sides it was full on, to avoid slipping etc.  Would this be a useful
option to add to the core engine as well?

Mal

-----Original Message-----
From: ode-admin@q12.org [mailto:ode-admin@q12.org] On Behalf Of James
Myers
Sent: 03 December 2002 22:35
To: ode@q12.org
Subject: Re: [ODE] Problem with rolling sphere...

I am having a similar problem.  I read in the archives
that you need to add a force opposite to travel
direction because (for example) a pool ball will
actually be losing energy due to squashing the carpet
as it rolls along.  This effect is not simulated
automatically.
I tried several variations, then one that works best
for me is to add a force of about
-(.08*dBodyGetLinearVelocity) per tick, but the
spheres tend to roll somewhat off course as they slow
down.

James