public bool Modify(int index, Geometry.Light light)
        {
            bool rc = false;

            if (index >= 0)
            {
                IntPtr pConstLight = light.ConstPointer();
                rc = UnsafeNativeMethods.CRhinoLightTable_Modify(m_doc.m_docId, index, pConstLight);
            }
            return(rc);
        }
        public int Add(Geometry.Light light, ObjectAttributes attributes)
        {
            IntPtr pConstLight      = light.ConstPointer();
            IntPtr pConstAttributes = IntPtr.Zero;

            if (attributes != null)
            {
                pConstAttributes = attributes.ConstPointer();
            }
            return(UnsafeNativeMethods.CRhinoLightTable_Add(m_doc.m_docId, pConstLight, pConstAttributes));
        }