DWG-imports to shared coordinates rotates after saving and reopening, what am I getting wrong

[carl]

I have been using Revit and its coordinate systems for well over 8 years and I would say i'm an advanced user, usually having no trouble with getting things set up the right way. BUT, sometimes I still get all confused using DWGS and shared coordinates. When I belive everyting is set and I close and reopen a revit file, all my linked DWGs have rotated and I cant replace them in the proper positions. Makes me go crazy (I have searched the forums but my tired head still does not connect the dots at this moment..).

This is my current workflow for a project, what am I missing?

1. I start with drawing a building. PBP is at Internal Origin, SP is 0,0 no rotation also at Internal origin.

Then I link a site dwg with the building outlines and a known position of world coordinates (green arrow). I rotate it in place and aquire coordinates from the dwg, to get the rotation (because of line jagging in imported world coordinate dwg site file, i have moved the objects closer to the origin in this file and kept a reference point). Then I specify the actual world coordinates at the known point. Now i have a true north with proper rotation and if I export DWG from shared coordinates they align nicely with other DWGs using world coordinates.

Now i want to IMPORT some nice site plan drawing or similar drawn in autocad using world coordinates. I want the 0,0 in the autocad file align with the 0,0 of the Survey point. I also want to do this in a true north view inside of Revit to just have the building sit nicely atop of the site dwg.

This is where im starting to get lost. I import it using "current view only"  and it a little pop up tells me exactly what i want. Then I look at the result and Im lost. The dwg seems to be aligned with project north and not true north! 

I set my view to project north and redo it. Niice - it works. I reset my view to true north. Now it looks like I want.

Then I close my file. And Revit asks me something. I dont know what to say.

I try the first one. Then I reopen my file. I go to my site plan view. And i cry. The dwg has moved! and my first dwg as well. AndI cant redo the workflow without renaming my dwgs because the "already share coordinates". I make new dwgs and I try all options but the result is always the same! The dwg are not in position when i reopen the file. .

How can I just keep things in place?

[barthbradley]

A lot to unpack here, but first, when you open the DWG and go to Manage UCS, is there a "Revit60" named UCS? Second, did you name the Shared Site it's associated with in Revit and do you have multiple named Sites in Revit - each representing a different Survey Point Origin?  

AH! I see a problem. The coordinates are too much for Revit.  

https://knowledge.autodesk.com/support/revit/troubleshooting/caas/CloudHelp/cloudhelp/2019/ENU/Revit...

...try unCLIPPING the Survey Point before Specifying Coordinates at Point.  

[barthbradley]

Wait a minute. Are you Specifying Coordinates at Point after Acquiring Coordinates? That doesn't compute. 

...sorry for the unorganized feedback here. I'm reading and re-reading your workflow trying and understand it.  If you Link in the DWG, move it to where it should be in the Revit Project and then Acquire Coordinates - then you are done. The Survey Point Origin is now located where the Link's WCS Origin is located.  Any DWG that you Link in afterwards by Shared Coordinates, will be placed so that their WCS Origin is at the Survey Point Origin.  

[rbarbosa8DQGJ]

The True North from Revit to Autocad is always a problem...  My suggestion is to link the dwg (if it has coordinates and north correctly set) and then Acquire coordinates from dwg.

[ToanDN]

If you link DWGs using shared coordinates, don't tick the box Current View Only.

[barthbradley]

Actually, True North is at 12 o'clock in AutoCAD and it's at 12 o'clock in Revit with respect to the Angle to True North - not Project North - if the DWG is Linked into Revit via Shared Coordinates.  FWIW. 

[barthbradley]

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@ToanDN wrote:

If you link DWGs using shared coordinates, don't tick the box Current View Only.

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Why?  Serious question.  

[ToanDN · Accepted solution]

You workflow is correct.  When you close the Revit file, just choose Disable shared positioning.

[ToanDN]

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@barthbradley wrote:

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@ToanDN wrote:

If you link DWGs using shared coordinates, don't tick the box Current View Only.

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Why?  Serious question.  

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It is mainly for taking care of the DWG on Z direction, like if you need to move it up or down to match with the Revit model, or to create topo from it.

[carl]

Thanks for your feedback, I’m sorry if I was a bit unclear. Because of the coordinate distance issue, I cannot just import my site plan with the actual coordinates. This just results in jagged lines issues like this post
https://forums.autodesk.com/t5/revit-architecture-forum/dwg-import-lines-jagged/m-p/9803643#M300609

That’s why I wblock my site into a new temp file with geometry closer to the dwg origin, keeping a reference mark for known coordinates in the actual site plan. These coordinate I then type in manually… Maybe there’s some other way…

I will try to unclip the survey point as you mentioned when I get back to the computer tomorrow and see if it makes a difference.

[carl]

Thanks, will try tomorrow!

[barthbradley]

You could move the original CAD closer to the Internal Origin, unclip Survey Point and Acquire Coordinates.  But then subsequent DWGs,using the same WCS Origin, Linked into Revit via Shared Coordinates will likely be screwed up because the SP Origin is too far away.  So your solution is valid.  Another approach would be to Link the DWGs into their own RVT and Link that RVT into your Project.  Six of one, half dozen of another as far as for headaches though.     

[carl]

It works! Thanks a lot! I thought i had examined the "disable shared positioning" option but i've must made some mistake... Might be I'm only working ~one day a week beeing on parental leave most of the time, so my mind is a bit clouded at the moment.

I don't really get why the "current view only" option affects the positioning. Most of the time I usually only want to import my dwgs to one view only unless im doing a 3d site and topology work. However if i flip my view to project north I can import the dwgs to current view only, a bit of extra clicks but at least its possible.