[ODE] Adding Negative Masses

[Wesley Smith]

Hi,
I'm curious is if it's possible to use dMassAdd() to add a negative
mass to a large mass and have the result be as if a chunk of that mass
went missing of the corresponding form.  For  example, if I do
dMassAdd(), combining 3 objects, and now want to take one of them
away.  Assuming that I've kept some record of the original small
body's mass, can I negate it's mass params in the dMass struct and
then call dMassAdd(&compositeMass, &body2) and have it behave as if
body 2 had been taken away?  I'm guessing yes, but I want to be sure.

thanks,
wes