autcad import line problem

[bheng]

i have imported a dwg from the a surveyor into revit and lines appear to be "squiggly". it appears to "squiggle" as i zoom in and out but looks line in autocad.

what can i do to make it appear " normal" ?

thanks!

[greg.mcdowell]

Sounds like a video card/ driver issue.

[mibzim]

Oh oh.... ok, quick, tell me you didn't import the file origin to origin, and that the CAD drawing is miles away from the origin? We had this problem with importing CAD files a long way from the revit origin, and it is STILL causing us IMENSE problems!!.

Do NOT try and match up an ACAD origin and a revit origin in order for the files to export to the CAD coordinate system. This messes up the graphics with Revit, and causes it to crash FREQUENTLY when saving to central. Its basically because the information ends up being too far from the origin and the model doesn't work well when its too far away - all the 3D coordinates become too large and freak out the graphics. I think autodesk just published a white paper on it because of the problems we had.

Instead, make sure you use the shared coordinates tool.

[bheng]

mibzim,

spot on. we were doing what you described. hope autodesk addresses this problem in V10!

[mibzim]

Listen, find out how to use the shared coordinates and make sure you only import the CAD file centre to centre, and dont draw the revit model miles away from the origin. Its REALLY important that you do this, you won't believe the headaches we've had.

We have figured out how to manage the problem, but even so our details are basically unreadable on the screen, and we have at least one crash per day per user. At one stage i was getting about two or three productive hours a day, with up to ten crashes that do not save back to central.

Autodesk has known its an issue for ages, thats why they invented the shared coodinates tool, as a legitimate workaround. We have been trying to get them to fix up files, find a solution, or help in any other way since Spetember last year, and they have been next to useless. Don't rely on them to fix it any time soon because i think its fairly difficult - you need to change the way you set up your files quickly before its too late. I really can't stress this point enough!!

[sbrown]

I've had files that even though we imported center to center, there was a still display issues. We had to physically move the acad geometry in acad closer to the origin, just make sure you do it smart, like an even X,Y number so you know how to xref back into the originial if needed.