[ODE] ODE Message 2: Vector has zero size and NaN values.

[Mark Williams]

> Hi all,
>
> I'm currently working in an interactive application with physics and
> I've been getting this strange warning message:
>
> ODE Message 2: Vector has zero size
>
> coming from dNormalize4() and shortly after this, ODE starts spitting
> out invalid floating point values (NaNs) for body positions inside the
> simulation.
>
> Any clue has to what can usually cause this error? I've checked
> collision functions but everything's quite simple and no strange
> values pop up.
>
> I'm hammering in positions for dynamic collision bodies every few
> frames so I thought this might influence the contacts, but I really
> have no clue has to what I should be looking for.
>
>   

The most common cause of getting NaN body positions I've seen so far is 
when the mass matrix is set incorrectly. Could this be the problem here?

Cheers,
Mark