[ODE] 2d moment of inertia

[Josh Singer]

Hi folks,

My ODE project is in glorious 2-d, using the plane2d joint extension by 
P. Serocka. So objects only ever rotate around the z axis.

I have concocted some fancy code for computing the moment of inertia of 
my objects around the z axis, and I understand that this goes in the 
dMass object as the I33 element.

My question is, what can I safely enter for the other elements, the 
other two moments of intertia I11 and I22, and the three products of 
inertia?

Can I just put zeroes in all these locations, since there will never be 
any rotation about x or y?

cheers,

josh s