Problems with shared coordinates

[-luisa-]

A job in the office (Architects!) has experienced several setbacks in trying to get shared coordinates to work. I wasn’t around when it was first set up and unfortunately I don’t know how and/or when things first started going wrong. Error messages kept appearing and suggesting that models had been moved when in fact they hadn’t. 

In an attempt to fix it once and for all I tried resetting the shared coordinates. Here is what I did, and below I explain the structure of the models in case that helps get through to the bottom of the issue:

• Opened model, detached from central, removed any revit/cad links (to make sure I was working from a blank slate as much as possible);
• Linked a blank revit model (with only 1 wall) Origin to Origin;
• Acquired coordinates;
• Removed the link and saved;
• Repeated this process for each of the 10 models in this job, and then;
• Opened the site model, linked the OS map, acquired coordinates;
• Linked each of the other blocks in the site model (as overlays);
• Published coordinates and Saved positions to each of the linked models.

No one was using any central/local model during this process but myself. No warnings and everything seemed to be going well.

When I now try to link blocks among each other – say for example trying to link Block B into Block A – I get the following error message: Shared Sites in the link '3136_Block B_R16_WS.rvt' have been modified, but not saved back to the link. Upon reopening, instances of the link will return to their last Saved Positions. You can Save the link later via the Manage Links dialog.

I cannot stress this enough: the model has NOT been moved and the positions WERE saved when coordinates were set up. I can choose OK and the models will come in the correct location.But I am lacking trust!

This is the model set up: 

• Site model (has all other models linked as overlays)
• Block A up to Block G (7 models)
• Units (contains the internal layouts of all blocks in one file)
• Landscape

Any help would be very much appreciated.

Luisa

[Alfredo_Medina]

Shared Coordinates is a relation between 2 files, only. Based on your description, you reset the relation between, let's say, file "S" (the site), and files, A, B, C, D... great; that does not mean that the relation between A and B, A and C, B and C, etc... has also been redefined. That explains why you see the error message only when you "link blocks among each other".

[-luisa-]

Alfredo,

Thank you for replying.

That makes sense, so is the solution hittingthe 'save now' in each of the blocks? I have avoided using it as I worried it would then compromise the relationship with the site model.

[Alfredo_Medina]

Hi, Luisa,

When you say you "link blocks among them" are you referring to linking again the individual, separate models of the buildings, into each other, again, even after having linked them in the site model? Or are you referring to the models of the other disciplines? Because usually you don't need to link the other buildings of a site in the models of one building, but only in the model of the site. What you need to do in the model of a building is to link all the other models of the other disciplines for the same building. That is something that I would like to understand better from what you are doing.

And in reply to your question of "save now", es, this question from Revit does the same thing as the other question that shows up when you attempt to close the model, the one that says something like "the position has changed, do you want to save back to the linked model?" If you don't use any of these two options (save now or at closing) the models never get their position updated.

To be sure that the position of the models is the same, have a common point of reference that reports the same coordinates in all the models. This point is initially set up with "Specify coordinates at point". Ideally, that point should match the default origin point of the Site plan model.

[-luisa-]

'are you referring to linking again the individual, separate models of the buildings, into each other, again, even after having linked them in the site model?' 

Yes.

Unfortunately we also need to link the models among them - ie Block A needs to be linked in Block B, and Landscape also needs to be linked in Block A & B, etc. This is because the individual drawings for blocks were set up in each model, and we need to see data contained in other models. We haven't got any consultants models yet.

I thought as long as all models had been properly set up and all shared the same coordinates, they would work in any combination among them?

Thanks again.

[Alfredo_Medina]

This approach sounds complicated, and I don't think it is necessary or convenient. That's what the site plan model is for. That is usually the only model that needs to contain all the buildings. The model of a building contains only the models of the other disciplines for that particular model. The model of the site publishes coordinates to the architectural models, and the models of other disciplines of a building acquire the coordinates from their correspondent architectural model.

[-luisa-]

I agree, it is very complicated! Alas it was not my decision, I am only looking for advice on how to make coordinates work at this point. Do you think this is at all possible?

Thanks.

[Alfredo_Medina]

My opinion is that this setup can get complicated in the long run; it should be simplified in preparation for what comes next, which is a set of approx. 5 models for each building, the models of the other disciplines. Also, remember that for each building you need to do coordination, clash detection, worksets, exporting, printing, etc, so they better be a set of models per building, not a compilation of all the buildings again. Leave that overall task for the model of the site plan. 

[SteveKStafford]

What you describe should be possible. I frequently set up projects like that.

I should start by noting that when model positions are changed in the master site file it is sometimes necessary to use Publish Coordinates on all the linked models, even those that have not be altered. I've observed inconsistent results where sometimes the location of a linked sibling does not adjust (update) when viewed in another sibling model. Using Publish Coordinates seems to force these linked files to refresh properly when a model is opened, even though it might seem unnecessary for those that didn't change. As such, it is possible that the block links appeared to be getting out of alignment for this reason...causing you to try to reset everything.

The part of your post that I don't understand yet is the mention of Units. I believe that these are linked into the Block models, true? If these Units are also linked into the master site file then it is possible that there is some discrepancy between the models. Can you explain that part of the puzzle further please?

As for the specifics of the process, as Alfredo mentioned earlier Revit files can only maintain a single shared coordinate relationship. However the Master Site model has a relationship with the survey file and that relationship is passed along to the other linked files when the Publish Coordinates tool is used on them. This means they all share the same understanding of coordinates relative to the one survey file. That permits us to link those models into each other (creating a circular reference condition) using Auto - By Shared Coordinates.

For this to work consistently the Revit master site file has to be regarded as the manager for all the other linked file relationships now. If it helps think of the master site file as the Parent and each of your Block models are the children or sibling models. The siblings should never be moved within another child file they are linked into. Put another way the brother and sister should not be moved from within the sibling model they are linked into.

The structure/process looks like this:

Master Site (parent) - Link survey - Acquire Coordinates

Master Site - Link Block models (children: brothers/sisters/sibling) - position and Publish Coordinates

Block Model (sibling) - link other Block Model (siblings) using positioning: Auto - By Shared Coordinates

[-luisa-]

Steve,

Thanks for your help. I am 100% on board with that you say, which makes this even more frustrating as I followed the exact steps you suggest.

The ‘Units’ model has been trialed in our company for initial stages of the project, up to planning. Although controversial – yes – it has been working pretty well in addressing issues we usually encouter: our computers/server(?) cannot handle linked groups (for the internal layouts) as the amount of links makes navigating through the model a nightmare – very very slow. So in order to avoid huge models with several blocks, each block model contains the external envelope and communals; the units model is then split into worksets by block, which allows us to successfully use the same group across several blocks without needing to update the layouts several times; at the same time we can load only the required workset into each individual block. Clever innit.

But going back to the initial problem, from what you say, I should not be getting this error! I did exactly what you describe, the ‘master’ Site model initially acquired coordinates from the OS Map, then from that one model I published to all other 9 models and saved positions. So they should all be coordinated amongst each other.

But here lies the problem – once I published coordinates, I never moved the models again. So why, when linking A into B Auto – By Shared Coordinates, would it say the positions have not been saved? The models do come in in the correct location, but should I hit ‘Save Now’, or would this then compromise the relationship with the Master Site Model? For now I have hit ‘OK’, and everything works normally, but Manage Links dialog insists ‘positions not saved’?

It’s messy.

[SteveKStafford]

Are these Unit models attached links versus overlay? When you link a Block model to Master Site the Unit Model(s) is/are coming along?

I have seen the warning message in the past even though everything seems to be working as intended. It is as if the Insert > Link RVT process causes Revit thinks it is "moving the Link" during insertion and generating the message.

I think that I decided that linked DWG files that were part of the "block" models were causing the issue as it went away when they were removed. It wasn't conclusive enough to me though...it may have been merely coincidence but since the issue stopped happening we moved on. I think that was using Revit 2015 at the time.

What version and update version are you using for this project?

[-luisa-]

 I only just upgraded them to 2016, they were originally in 2014.

Other bits:

16.0.462.0
20150506_1715(x64)
Service Pack 1

Unit link as all other links are set to overlay. Initially we had attached the links in the site model, but this created circular references and made opening models slow. 

We have no cad files linked in the blocks (I removed all links before starting the whole resetting coordinates process). 

I might try detaching a couple of models from central and testing the 'Save Now' button to see if that helps...

[-luisa-]

We have tried re-publishing coordinates to all models but problems persist. I've narrowed it down to the Project Info workset - it keeps making itself editable and making model 'positions not saved', each time a model is linked in another model. Autodesk are now looking into it, I will post any further developments. Thanks for everyone's help so far!

[-luisa- · Accepted solution]

Reporting back to say that Autodesk suggested (after a few other failed suggestions) upgrading all models to Revit 2017.

This worked!, and all files and shared coordinates work well now and the weird warnings are gone. Happy days. Thanks everyone!

[Anonymous]

+1 That is the correct answer indeed. No more weird mambo-jumbo.

Thank you!

[andybrack]

Luisa,

Am just wondering what were the suggestions that Autodesk gave you before you upgraded to v2017?  I have a project in 2017 that is set up the same way (less the Units) and am getting the 'Position not saved' error when trying to sync to central. The error seems to come and go for a few users, but I haven't been able to see any consistency.

I've been trying to figure out where the error is coming from, but haven't pinpointed it yet.

Thanks in advance,

Andy