public extern static void dGeomPlaneGetParams( dGeomID plane, ref dVector4 result );
public extern static void dWtoDQ( ref dVector3 w, ref dQuaternion q, out dVector4 dq );
/// <summary>
///
/// </summary>
/// <param name="_mass"></param>
/// <param name="_c"></param>
/// <param name="_I"></param>
public dMass(dReal _mass, dVector4 _c, dMatrix3 _I)
{
mass = _mass;
c = _c;
I = _I;
}