i have a sphere and plane setup with gravity. i expect that the sphere will bounce back from the plane but this is not always the case. it depends on the radius of the mass of the sphere. i might miss some math here but don't get it why the mass radius changes the bounce behavior radically.
i change radius to a number about 1 in this line:
dMassSetSphere(&sphere_mass, density, radius);
and the bounce does not work.