Revit Architecture Forum
Welcome to Autodesk’s Revit Architecture Forums. Share your knowledge, ask questions, and explore popular Revit Architecture topics.
abbrechen
Suchergebnisse werden angezeigt für 
Anzeigen  nur  | Stattdessen suchen nach 
Meintest du: 

Site Plan CAD Linked into Revit - Some Objects Appear Shifted

5 ANTWORTEN 5
GELÖST
Antworten
Nachricht 1 von 6
Anonymous
691 Aufrufe, 5 Antworten

Site Plan CAD Linked into Revit - Some Objects Appear Shifted

Hello all, 

I have been building up a BIM model for some time, and recently I needed to link the site survey CAD plan into the BIM model. My workflow was as follows:

1. I adjusted the Internal Survey Point and Project Base Points of the BIM model to match the location of the site as it should be located on the CAD. 

2. I linked the CAD in, but the plan was shifted a couple hundred meters away from the required location, so I un-pinned the CAD and moved it.

3. I saved the Revit model and Revit prompted me to update the changed Shared Coordinates into the CAD. It repeatedly prompted me to do so, up to a certain point I thought there was a bug in the system and force exited.

4. After I restarted the Revit, I noticed that all of the survey point crosshairs in the CAD drawing (which were in the same layer) shifted from their original location, while the rest of the CAD drawing (such as the level annotations, the road alignments, etc.) stayed in the same place. 

5. I opened the CAD file and the crosshairs are in their correct location.

6. I've tried to a) delete the new UCS generated by REVIT60 into the CAD file, b) unload/reload the CAD, c) save the CAD as a new name, d) link the CAD into a new REVIT model, but none of the attempts corrected the problem. 

 

Here are two images to explain the problem:

Image 1 The original Cad survey plan as viewed in AutoCAD before and after it was imported to REVIT

Capture_CAD.JPG

 

Image 2 the survey map CAD linked into the REVIT model from Step 4 onwards. notice that a) ONLY the crosshairs (in green) have shifted from its correct position and b) the model is still not in the correct location after i unloaded and reloaded the CAD. The cross-hairs are in one single layer in the CAD file.Capture_revit.JPG

 

In retrospect I probably should not have force-exited the program, but alas what's done is done.  Is there any way to resolve the "shifting" of one single layer in a linked CAD file? Im not sure if it's a CAD problem or a Revit problem. Thanks all!

 

 

 

5 ANTWORTEN 5
Nachricht 2 von 6
ToanDN
als Antwort auf: Anonymous

Here is a simple workflow that works:
- do not change your project base point and survey point manually
- link the cad site plan in center ti center
- move the cad link to align with you model
- acquire coordinates from the cad link
Nachricht 3 von 6
barthbradley
als Antwort auf: Anonymous

They way you did it is fine too.  Step 1 was fine.  Then in Step 2, you would Link in to CAD via Shared Coordinates.  Did you?  By Linking it in via Shared Coordinates, the CAD origin would be placed at the Survey Point. This would have been  followed by a prompt to save/name the Shared Site in Revit.  Then in Step 3, you would receive another prompt when you saved/closed the Revit Project asking you to save the Site location back to the CAD Link -- which is exactly what you want to do.   It won't mess anything up in the CAD file, if that is what you were concerned about.  

 

 

 

Nachricht 4 von 6
barthbradley
als Antwort auf: Anonymous

...I have read #4 several times and I'm still not getting it.  Are you saying that only one layer in the Link shifted in Revit?  That none of the other layers shifted with it?  This is not possible. Are you sure the Revit view isn't askew.  In other words, are elements in the Link maybe at a different elevations and you are looking at the Link in an slightly askew 3D view?  

 

 

Nachricht 5 von 6
Anonymous
als Antwort auf: barthbradley

Thanks. Tried this method and restarted a few times, and it seems to be working fine now. But I had to specifically link the CAD in G/F Plan view, not in Site Plan view (which I had done in the previous times).  (N.b. my project north is  angled to true north). Fingers crossed...

Nachricht 6 von 6
Anonymous
als Antwort auf: barthbradley

>> "only one layer in the Link shifted in Revit"

Yes, it had seemed so the last few times I tried to link the CAD in. You could see from my images that only the level crosshair marks shifted. 

For those trials, I linked the CAD in while I was in "Floor Plan - Site" view, and the shift persisted even when I switched to a Floor Plan view of a different level. 

But seems the problem doesn't occur if I link the CAD in while I was in "Floor Plan - GF" view. 

Sie finden nicht, was Sie suchen? Fragen Sie die Community oder teilen Sie Ihr Wissen mit anderen.

In Foren veröffentlichen  

Autodesk Design & Make Report