Problems with shared coordinates

[emmanuelbee]

I have a dwg site plan that I'm trying to link into revit using shared coordinates, when I link it, it keeps coming in at the wrong place not aligned with the building. I thought there might have been an issue with the site plan  so I copied and pasted the site plan into a new dwg drawing file and pasted at 0,0,0 so that I could keep the same coordinates. Now when I link it into the revit model using shared coordinates it comes in at the right place, aligned with the building. I dont why the original dwg file doesn't come in at the right place but the copied version of it does even though they are both using the same coordinates. Even though the copied version of the site plan works fine. I would preferably like to use the original site plan as it has a few xrefs in it. any solutions as to why the original file doesn't come in at the right place with shared coordinates in revit ?

[emmanuelbee]

 'Inserting with shared coordinates only works if you have published or acquired coordinates from a different file' that's exactly what I've done and like i said i copied and pasted the site plan into a new file, I pasted at it 0,0,0 to make sure I kept the same coordinates as the orginal file and somehow that works. but the orginal file doesn't. its just really strange

[Anonymous]

Here's my detective approach:

1) Your method usually works fine.

2) Your method works on one file, but not another file. 

So to me, the problem is not with the method but the file that's giving you problems. This is where I think your assumption isn't quite correct, from your original post: "I dont why the original dwg file doesn't come in at the right place but the copied version of it does even though they are both using the same coordinates."

My conclusion: If you are inserting them both the same way, into the same model using the same Revit shared coordinates, then your 2 CAD files must not be using the same coordinates. 

So the question to me is: what coordinates are the original CAD file using, and how do you find out? I would go to the file's UCS dialog box in CAD, and see if in fact 'World' is the correct 'World' coordinate system. As you know, 'World' has special properties and is not dependent on what it's called. Are there other coordinate systems in the file? Etc.

[barthbradley]

Maybe I'm misreading you, but Revit's "Origin" has no bearing on the survey map - or with sharing.  

[Anonymous]

Sorry, I'm trying to understand what you have done already.  This is what I would do below:

1. Insert linked CAD (unaltered version) to new revit template

2. Align known building corner/location to Revit origin (0, 0, 0) and project base point

3. Acquire coordinates from CAD file therefore moving project base point to world location (PBP should display the coordinate locations matching your CAD file, if not, something has gone wrong)

4. insert building model into site model at desired location

5. Publish building model location, save location as something recognizable, save site model file, close

6. Open building model and insert site model using shared coordinates.  

7. Everything should be in the right location

Let me know if that works.  

[Anonymous]

I doesn't seem to in this case.  It was mentioned that there was an alignment to 0,0,0 coordinate, which might have caused issues if it wasn't revit's origin in one of the models for the project.  This wouldn't affect the survey point, but it's easier in my opinion to understand where you are if you start at Revit origin.  

[emmanuelbee]

the thing is the building model is the main part of the the project so i can't link on to the site plan it has to be other round, the site has to come into where the model is. I think there is something wrong with the original site plan because when i zoom extent, it doesn't centre the plan its strange. I 've attached the site plan if anyone wants to have a look at what might be the problem.

[Anonymous]

The steps I listed will leave you with the site model in the building model, the same way that linking them into one another would.  It will cause a loop if you have them both open at once, but if you link the building model into the site model first, it should come in as a block and be easy to manipulate/position.  Then, after you publish its location, revit will know exactly where to link your site into the building model.  

[emmanuelbee]

ok I'm going to try it

[barthbradley]

Here's my suggestion. You're survey origin is over 85000 miles away from the project site, meaning that you pushed your Survey Point well beyond the limits that Revit can work with when you Specified Coordinates at Point. So, after you "Specify Coordinates at Point", select the Survey Point, unclip it and move it to the Project Base Point Location and then re-clip it.  

Before doing that however, unclip your Project Base Point and select "Return to Startup Location".  Does it jump off the screen? In other words, is it relocated to a position far, far away from the building?  

BTW @emmanuelbee: thanks for posting the dwg. It helps.  Want to post the rvt as well?  Might be the easiest way for us to help you troubleshoot?  ...or we could keep this thread going onto page 3, 4, 5, etc. Ha! 

[Anonymous]

I just did a little demo, and it works.  The comment about your survey origin being crazy distanced is absolutely correct.  There is a nuts large radius to this.  It is fine though, all you have to do when you publish the coordinates is hide the survey point and then it zooms extents just fine.  See attached clips from the process.  Ask questions if its still not working.

1. cad aligned to origin/PBP

2. CAD 2, I aligned to hypothetical project north

3. Acquired coordinates, also of note, if you switch from project north to true north at this point revit should be able to tell where true north is now vs the aligned project north

[Anonymous]

4. shows dummy demo walls in new building model aligned to PBP at project north alignment

5. shows the crazy survey point in building model.  hide this or edit your file in CAD, this process should still work.

6. shows site cad inserted in exact position in building model with shared coordinates.  I don't know why it was only visible in the "hide" mode

[emmanuelbee]

I've tried to upload the revit model on here but it doesn't work its 20mb

[Anonymous]

You won't get any errors due to the survey distance if you do the process steps listed in my first step by step, however, this is a huge pain and it is advisable to fix.  

[barthbradley]

@emmanuelbee; did you, by chance, get a message like this when you specified coordinates at point? 

[emmanuelbee]

I got that error message a while ago when I was trying all sorts of ways to fix the problem

[barthbradley]

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@Anonymous wrote:

You won't get any errors due to the survey distance if you do the process steps listed in my first step by step, however, this is a huge pain and it is advisable to fix.  

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Not following you @Anonymous, but this is in my wheelhouse. What is "a huge pain and...advisable to fix"?   

[barthbradley]

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@emmanuelbee wrote:

I got that error message a while ago when I was trying all sorts of ways to fix the problem

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It's starting to make sense now. Can you return the PBP to it's Startup Location (per post #29), and tell me what happens?  Or, just post your Revit file?  

[emmanuelbee · Accepted solution]

I've somehow managed to fix it using a combination of both @Ariel steps and your method.

1.   I moved both the project base point and the survey point to the same corner of the building 

2.   Then I inserted the cad file using either origin to origin/ center to center and then moved the site to line up with the corner of the building where the project base point and survey p... was and then I acquired coordinates.

3.   Then I saved the position of the link and VOILA!

To test it out with using shared coordinates, I deleted cad file and reinserted using shared coordinates and it came in at the right place.

I think it just wouldn't work without using acquired coordinates first.  I was trying to do it using only shared coordinates like in this tutorial https://www.youtube.com/watch?v=nK6snx8vvy0 , the crazy thing is this shared coordinate method normally works without having to acquire coordinates first but this time for some unknown reason, it just would not work.

[Anonymous]

The distance of the survey point to the revit origin is a huge pain.  If you don't have your cad linked I think we all know it causes inaccuracies and how awful that can be.  Even if you have it linked correctly and there are no errors, who wants a survey point on file linked so far away?  That's all I meant.

[emmanuelbee]

The whole thing just gets annoying and confusing, I wish there was just one method that worked all the time but anyway its done now, Thank you and @barthbradley for your help