public unsafe static void SetAnisotropicFriction(this CollisionObject obj, ref OpenTK.Vector3 anisotropicFriction) { fixed(OpenTK.Vector3 *anisotropicFrictionPtr = &anisotropicFriction) { obj.SetAnisotropicFriction(ref *(BulletSharp.Math.Vector3 *)anisotropicFrictionPtr); } }