By Matthew Anderson, PE
Ever wonder why the inlet you added in Hydraflow Storm Sewers (HSS) shows up as a Headwall in Civil 3d? Why isn’t my LandXML import as I expected? Mark Scacco’s AU presentation and LandXML hack is a godsend. I at least now can round trip my data and not deal with a plethora of Networks.
But, I have always found LandXML import behavior odd. I had to dig deeper. To find out more, join me after the jump…
The Civil 3d object model is based on structures and pipes. HSS sizes pipes and inlets. LandXML is the language in between.
Isn’t an inlet just the frame? Where does that leave me? Let’s take a look at HSS. (This is version 2005)
The HSS program model contains the following structures.
All of the Inlet/Junctions are of some sort of Inlet Structure, beyond the Outlet and Inlet 1. I have attempted to find anything that might indicate Structure Size in 2005. I can’t find it.
Okay, how does that affect Civil 3d? A little XML Notepad exploration is needed.
After exporting the LandXML from HSS, the structure diameter and lossCoeff is missing from the LandXML output. Are they supposed to be? Let’s import it into Civil 3d anyway.
Civil 3d imports the HSS design as follows where the Name field is the HSS Inlet/Junction Type and the Description is the Civil 3d Part Description that Civil3d selected. Please note, I did get a number of Multiple Part Families warnings from Dana’s child, Panorama.
Civil 3d matches the un-sized inlets structures to the first non-round or rectangular Part in the part lists. In this case, it’s a headwall.
It appears to be a limitation of the LandXML schema. Hopefully, Civil 3d will allow a LandXML Structure Mapping template. Good news, Start with Civil 3d. With Mark’s little hack, your inlets will not become Headwalls.
Please note that this works with both 2003 and 2005 versions of Hydraflow Storm Sewers. (I haven’t had the heart yet to uninstall 2003)