I have a 2D polyline feature class representing underground utilities of various types. Lets say for sewers I have a simple line but no elevation values were included in the attribute from the CAD files. I can look at the CAD drawing PDF's that were provided and ascertain the start and end elevations of each pipe. I see there is a tool "Feature to 3D by Attribute" where I can put these start and end elevations in the attribute table and convert the 2D line to 3D.
My question is, how do I know which field applies to one end of the line vs the other? Does the tool attribute one field to one end and the other field to another end based on direction or something like that? For instance, field 1 is the northern/eastern most end of the line and field 2 is the southern/western most end of the line?