Revit model larger than 2 miles across!

[Dean Camlin]

Actually, the error message reads: "Revit cannot import [site.dwg] because it will create a Revit model that is larger than 2 miles across. This can cause inaccuracies and instabilities. Either select a different Import units setting or adjust the project size before importing."

I've done all I can think of to reduce the size of the AutoCAD file from my civil engineer, including writing a smaller block with the minimum CAD info I need to import, and I still get this message. I have never heard of adjusting the Revit project size & can't find anything in the Help files about this. Any suggestions?

[Steve_Stafford]

This is because geometry farther than 2 miles apart exists in the cad import. You can xref (attached) this file into a separate container cad file first and you'll be able to import the file like before 2010, center to center. If you can eliminate the elements in the cad file that are "probably irrelevant" to your project first then you should be able to import it without first putting it in a "container" file.

[ws]

Just a thought - I had this error message when I tried to import a modest dwg file with the wrong units - metres instead of millimetres or somesuch.

[Dean Camlin]

This is because geometry farther than 2 miles apart exists in the cad import. You can xref (attached) this file into a separate container cad file first and you'll be able to import the file like before 2010, center to center. If you can eliminate the elements in the cad file that are "probably irrelevant" to your project first then you should be able to import it without first putting it in a "container" file.
Thanks, Steve. I thought I had done that by editing the AutoCAD file (ZOOMing All, selecting for stray elements out in the great beyond, setting reasonable LIMITS, etc.) first, but now I'm breaking it into smaller blocks & importing them separately.
Any ideas what they mean by increasing a Revit project's size?

[Steve_Stafford]

My understanding is that there are two "mathematical models/systems" inside Revit, one for graphics (on screen display) and the other for model information (printing/plotting etc). Having data that defines information that is greater than 2 miles in diameter begins introducing a greater chance for calculation errors and therefore can cause inaccuracy in what we see on screen. Perhaps you've noticed a snap icon that seems "confused" and doesn't appear directly at the end of the element at some time in the past?

2010 is a bit harsher in response to importing data that is larger than this 2 mile diameter tolerance. Harsher in that it won't let you import the file anymore. In 2009 it imported the file with a warning and aligned it using the Auto-Center to Center option.

I still prefer to import the civil data into a separate Revit site "master" file for this reason. I can "trap" this issue in that file and the building(s) file(s) can be imported into the Revit site file instead to have their coordinate relationship to the site defined and then published back to them. This makes the hassle of repositioning the building on site during design practically a trivial matter. If the building needs to move I just move the link in the site file and publish again.

[trombe]

...........to importing data that is larger than this 2 mile diameter tolerance. Harsher in that it won't let you import the file anymore.......................


My supportive resellers recently helped with this same problem in 2010 and thanks to them I was able to overcome most of my problems.
The 2 mile limit can occur in any plane not just horizontally. I had some import geometry that was in the vertical plane.
I intend to revise instructions to consultants after this event to overcome extraneous geometry, over limit geometry or remote datums.

cheers
trombe

[JasonK.183140]

Thanks Dean!!! My problem was due to a point in the vertical limit. I wouldn't have thought about that.

[paysna]

Thanks gentlemen, for having this very discussion, solved my very frustrating problem.

Cheers.

[patricks]

Yes 2010 is more strict about the 2-mile limit on geometry. However, it is actually more accommodating on WHERE that geometry is located in relation to the origin in AutoCAD. Before, you would get the 2-mile warning if anything was more than 2 miles from the origin in the CAD file. Now, it doesn't matter where the elements are in the CAD file, as long as there are no actual elements more than 2 miles from each other.

[joe.ehlers]

I narrowed the error down to two polylines that that had a radius in excess of 29,000 ft. Removed those two plines and all is well.

[rturner.236725]

Steve -

I have reviewed my project units, changed the units, looked at elevations for random points outside of 2 mile radius, zoomed extents on the dwg file all around and was not able to bring the entire dwg into the drawing.

I was able to bring about a quarter of the drawing in, but it would only allow about 50'-0" on the actual dwg file.

Once the drawing was imported as a link, I added elements to the existing dwg and it responded with the same "2 mile" rule.

I even started a new project to see if the import rules would change. I also cut and pasted the autocad doc into a new doc to ensure no existing points were erroneously on the plans.

Have I not exhausted all my options?

[patricks]

Install 2011. No more 2-mile limitation. :)

[eric.piotrowicz]

Yep but in 2011 its a 20 mile limit. Sure, right now I can't imagine ever exceeding that. However my first computer (mid 90's) had a 2GB HDD which seemed like a ton of storage capacity, now I have a 4GB MicroSD card in my phone, two more for my camera, and a 2GB one with USB adapter in my wallet for anytime I might need it, and a 2TB HDD in my computer.

Although to respond to rturner.236725. You could try Wblock'ing the entities and importing the fresh Wblock, usually this takes care of any problems I encounter. Have you checked that there aren't any frozen layers in the CAD file that might be hiding entities outside the 2 mile mark? What about blocks in the CAD file, have those been checked for space junk?

[dbaldacchino]

Have you tried the suggestions in the Tips & Tricks sticky thread? Here's the post (http://forums.augi.com/showpost.php?p=1039979&postcount=11)you need to look at.

[TroyGates]

Revit 2011 now allows you to work with dwgs up to any dimensional size. I believe you get a warning about instability with anything larger than 20 miles.

[dbaldacchino]

You're correct. Revit will issue a warning but still give you the option to continue linking/importing.