I am trying to build a parametric window family with opening lights. Despite assigning an angle parameter to the opening light, in many combinations of reference plane/reference line, it won't work! I tried making the opening light as a seperate family and got the unit to move through an angle (sometimes) by grouping everything. Trouble is the basic height and width parameters no longer work (now that the unit is a group). Does anyone know of a comprehensive book on Revit families?