NVidia PhysX question

Several things you'll need to look at.

1. turning force is too small. (moment too small)
2. Gravity too high
3. Friction between the surfaces too high.

Negative mass, should improve the above issues as there is less contact force, or a higher resultant force.

There could the force be acting in the wrong direction and as a result a negative mass, fixes issues (two negatives accidentally = a positive).

Otherwise, there is no way of knowing without some code.

Suggestion: Set up PhysX with +mass and fiddle with gravity, frictions and resistance to movement. Is mass value waaaaaay to high, this would cause extreme amounts of friction which (-)ve mass could/might change.

Unfortunately we don't have access to the inner workings of PhysX so it's hard to tell what/how negative values of masses are dealt with.

PureBlackSin

Its prob exactly the combination of what was posted above. When you set an invalid parameter in PhysX it should default to something valid, or just fail its creation.

Please call pRigidBody->GetMass() on the body you created with the negative mass - once it has reported the negative mass error. This will give you a starting point to begin to tune values from.