I am currently trying to create a script to implement in ArcGIS to convert Ellipsoidal heights to Orthometric heights. The idea is to make the height conversion to the data as it is checked in to the program. The height transformation of single points or lines is straight forward, however it becomes more of an issue when dealing with multiple vertex's in polygon's. Just wondering if anyone had any experience in dealing with some sort of similar situation? Any guidance is appreciated.