/// <summary>
        /// Calculates the principal axis transform.
        /// </summary>
        /// <param name="masses">The masses.</param>
        /// <param name="principal">The principal.</param>
        /// <param name="inertia">The inertia.</param>
        public void CalculatePrincipalAxisTransform(float[] masses, float4x4 principal, float3 inertia)
        {
            var btPrincipal = Translator.Float4X4ToBtMatrix(principal);
            var btInertia   = Translator.Float3ToBtVector3(inertia);

            BtCompoundShape.CalculatePrincipalAxisTransform(masses, ref btPrincipal, out btInertia);
        }