March 05, 2014
One of my favorite toys of all time was a magic set. Even though I knew how the "magic" worked, and even though I was performing the illusion, I was still always able to amaze myself.
The Marvel Avenger, "Thor" says he doesn't really distinguish that much between magic and science where he comes from. Maybe I can agree with him. I can learn how to trigger "magic" to happen reliably. The fusion of magic and technology doesn't mean technology explains away the magic. Just because I can trigger the magic and predict what happened doesn't mean I made the magic do what it does, or that I make the magic to do something else, and yet something amazing is still happening. The magic is there; we trip across it with fear, or we learn to harness it.
ArcGIS Geometric Networks are a like magic to me, and when editing features services based on networks the effects can be amazing. I didn't create this magic, but with a little knowledge of the effects of the geometric network behaviors built into the ArcGIS geodatabase I can use it to advantage when editing feature services; like when I edit feature services in ArcGIS for AutoCAD.
My Sewer system geodatabase is enhanced as a Geometric Network. I set a rule so that whenever I add a new 6 inch LATERAL feature to a GRAVITY MAIN I want the database to insert a new vertex in the MAIN line to maintain connectivity and then add a TAP junction at that point. At the other end of that LATERAL I want to add a SERVICE CONNECTION.
I draw one line in ArcGIS for AutoCAD, and after that feature hits the geodatabase when I SYNCHRONIZE, it creates one new feature, modifies one, and inserts two more; "Magic". I could also mimic this behavior before SYNCHRONIZING, by building an AutoLISP script to automate similar functionality, *( but that's deserves another post… AutoLISP scripting will become even more important as the next release of ArcGIS for AutoCAD 350 which includes an enhanced AutoLISP API among other things.) If however I add a LATERAL to a new GRAVITY MAIN in AutoCAD that hasn't been added to the geodatabase yet, then I may not get back the same result.
So then, can I edit ArcGIS Geometric Networks with ArcGIS for AutoCAD? The answer is: mostly yes, as long as I understand I am editing through a feature service. Editing geodatabases with geometric networks through a feature service is possible, but should be performed deliberately. You really need to be familiar with the rules, restrictions, and the sequence of events that are triggered when modifying data in a disconnected editing scenario like ArcGIS for AutoCAD. However, I can be deliberate with my work flows and perform tricks that amaze myself.