Saving current position of Linked CAD File

[Kev_D]

Hey

I have set up a work-sharing model with shared coordinates. The process i followed was:

1. Created new project with office template.
2. Linked CAD File with 'origin to origin'.
3. Acquired coordinates from this file.
4. Removed the CAD (Survey) File.
5. Re-linked CAD file (Survey) using shared coordinates.
6. Positioned my Survey Point & Project Base point to the desired location.

All seems fine until we had to reload the Survey file due to changes made. it did not position correctly, so i done the following:

1. Removed existing Linked CAD file
2. Linked new CAD file 
3. Published coordinates from Revit model to new Linked File
4. Moved the new CAD file into place.
5. Saved new position back to link.

I wanted to check it position is saved so I removed the new file and re-linked it, and..... ALL GOOD! 

So, thus far, i think I have followed this process correctly. However, now when someone else works on the work-shared file, even though they don't move or even touch the view with the CAD file linked into, they always get asked to save the position of the link.

Why is this happening? I'm thinking did something go wrong somewhere. Have I missed a step in the above process for linking and sharing coordinates?

[SteveKStafford · Accepted solution]

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1. Created new project with office template.
2. Linked CAD File with 'origin to origin'.
3. Acquired coordinates from this file.
4. Removed the CAD (Survey) File.
5. Re-linked CAD file (Survey) using shared coordinates.
6. Positioned my Survey Point & Project Base point to the desired location.

All seems fine until we had to reload the Survey file due to changes made. it did not position correctly, so i done the following:

1. Removed existing Linked CAD file
2. Linked new CAD file 
3. Published coordinates from Revit model to new Linked File
4. Moved the new CAD file into place.
5. Saved new position back to link.

So, thus far, i think I have followed this process correctly. However, now when someone else works on the work-shared file, even though they don't move or even touch the view with the CAD file linked into, they always get asked to save the position of the link.

Why is this happening? I'm thinking did something go wrong somewhere. Have I missed a step in the above process for linking and sharing coordinates?

No need to remove and relink the DWG. Their coordinate systems are matched already after using Acquire Coordinates.

The Save prompt is Revit attempting to save a User Coordinate System to the DWG file. This way an export to DWG from the Revit project can use Project Orientation and be linked into the DWG after having its UCS changed to the one Revit saved UCS.

After using Acquire Coordinates I disable Shared Positioning with the DWG to avoid the message. Revit thinks it should create the UCS, but we don't really need that. We just export using Survey Coordinate System to line up with the survey, if that's necessary.

Also, make sure the view the DWG was linked into is assigned to Orientation - Project North whenever you reload the survey file. If the survey was moved and rotated into alignment with your building then assigning the view to True North and reloading the file will cause it to spin out of alignment.

[barthbradley]

I'm confused by #6. Are you unclipping the Survey Point first?  You should be. 

[Kev_D]

@barthbradley Yes of course. I moved it to a known location outlined in the survey file (CB, MH, etc).

@SteveKStafford Thank you. I will look into what you said in more detail.

[Kev_D]

@SteveKStafford Regarding what you mentioned about always make sure to be in Project North prior to reloading the Survey file. Whenever I reload this, it reloads as True North, so lead me to believe I should be in True North.

[SteveKStafford · Accepted solution]

If it helps I wrote four blog posts, the first three biased toward site model and building model and the fourth discussing the survey being added to the building model directly. I written on the subject quite a lot over the years, this is a summary post.

Post 1

Post 2

Post 3

Post 4

[SteveKStafford]

Regarding what you mentioned about always make sure to be in Project North prior to reloading the Survey file. Whenever I reload this, it reloads as True North, so lead me to believe I should be in True North.

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If you read my fourth blog post mentioned in the other reply I describe what happens.

[barthbradley]

You didn't mention changing Project North/True North Orientation. So I assume Project North and True North are both at 12 o'clock. Surveys are typically oriented with True North at 12 o'clock.  What other orientation would it land at?   

[Kev_D]

Sorry, I did set up True North. That is the thing. When in Project North, I would reload the link, and it would come in at True North.

I obviously skipped something along the way. I will read over @SteveKStafford blog to get more of an understanding about the whole set up. 

[Kev_D]

@SteveKStafford Great blogs Steve. It makes much more sense now. I will continue to re-read them so it will stick in my mind. 

Interesting note about linking a consultants file in at 'origin to origin'. I would have assumed to share coordinates once we have a copy of their latest model. 

I would also assume that this whole process works the same in BIM 360?

[SteveKStafford]

BIM 360 does not support using Publish Coordinates so it is necessary to organize everything around being able to Acquire Coordinates or use the Specify Coordinates at Point tool (SPaC). Publish Coordinates alters an external file and that's the only function in Revit that supports doing that. In the cloud environment our project isn't organized in a file in the same way we see them in folders on our own server. That means no Publish Coordinates for now, or perhaps ever.

If all Revit models are linked Auto-Origin to Origin (like we did with AutoCAD) then each discipline only needs to model "inside/around the building" and alway line up. Shared Coordinates is primarily useful for exporting our work to share and align with Civil files or in Navisworks. If a design is reused on a site then other aspects of shared coordinates (multiple named locations) becomes useful.

Specify Coordinates at Point allows us to pick a location in our models and assign coordinates and elevation values. If we all agree on that location then each trade can define the same location with the same coordinate/elevation values and any export to CAD/Navisworks will be able to line up based on that Shared Coordinate system. No file relationships are defined using it so unlike Acquire Coordinates or Publish Coordinates it is entirely manual process. Revit models should be linked Auto - Origin to Origin still. Exporting using Shared Coordinates will produce the correct result, assuming everyone has used SPaC correctly.

[Kev_D]

Appreciate the info Steve. It's good to know about Publishing Coordinates in BIM 360.