As much I try to avoid this subject, I feel that I must explain why I don’t ever change the UCS in any form.
But I have an open mind so feel free to comment. I think it is about time we had a good rousing debate and cleared the air!
And this is just my (Dana) opinion. The other Civil3D.com bloggers can lay their reasoning out whenever they feel like it 🙂
In my last post, Take Advantage of Twisting Labels, I said that twisting your view was required to get your labels to automatically flip.
I have other reasons for prefering dview in general.
It comes from my first days as a new EIT at an engineering firm. I was dangerous in CAD…. They’d give me something seemingly simple to do- like change lot numbers on a site plan, and when they went back into the drawing they’d find all of their special attributed blocks exploded down to dtext and that sort of thing.
So I was told never to mess with anything.
As my skills grew, I noticed that if I started my work in a drawing that came from an architect sometimes when I tried to import a surface or something from the project, it would come in all strange. It was explained to me that the architect didn’t care when north was and rotated the UCS for whatever reason.
In the old days, your UCS Y axis was North to softdesk and Land Desktop. (here is an article I found that explains it well from a Softdesk perspective UCS vs Dview Twist )
So if you didn’t remember to change your UCS back to world before importing or exporting points, your surveyors where halfway to Tahiti before they realized their stakeout points were bogus.
Civil 3D apparently takes that off the table. I had a minor brainstorm last night thinking that “Why can’t we just change the UCS for a North rotation?” when Nick shot me down and sent me to search in help.
Â Go to your HELP menu and search for these terms and read up….
Autodesk Civil 3D object data AutoCAD World Coordinate System coordinates
I tried it. I labeled bearings, etc. on some parcels and alignments, then I changed the UCS and the labels nor the mapchecks changed.
I also did another experiment. I imported a list of points. Then I changed my UCS so that my Y axis was 45 degrees turned. I reimported the same list of points from ascii. They came in at the exact same spot. So it is truly using the World Coordinate System when dealing with Civil 3D objects.
In some respects, I think I would rather it react to the UCS. I think that an appropriate use of the UCS would be a North rotation.
However, that takes my original fears off the table. UCS changes won’t muck with the Civil 3D data.
But your labels only react to the view change.
Going through it both ways, it appears to me (and correct me if I am wrong PLEASE) that dview leaves you in world, but rotates the view. Like turning a sheet of graph paper on a table.
Interesting enough, it seems that you are actually dview twisting without realizing it in your second scenario because if you actually enter into the dview commmand after doing the UCS view change, you see that a dview twist has actually been applied for you.
In my mind, I’d rather not mess with Y period. There are too many people I share data with that still use Land Desktop and Softdesk. There is too much confusion over North these days and with increased pressure to submit in State Plane Coordinates and be GIS friendly that anything I can do to make sure that stays intact, I will.