Walls disappearing from DWG exports of views with overlays

[sven.129574]

Is anyone else having trouble with wall outlines or ceiling grids disappearing when exporting to .DWG format from Revit 2008?

Our engineers don't want separate .DWG files for floor plans and reflected ceiling plans -- they want everything in one file. We used to produce these by exporting an RCP view that had a floor plan as an underlay [Revit Walls.GIF]. This worked (if you turned off the casework before exporting) in Revit 9.1. But Revit 2008 is giving us fits.

If we select wireframe for the export, outlines of random walls do not get exported at all. For some such walls, the hatching for the wall gets exported, but not the lines for the actual sides and ends of the wall [RCP-Wire.GIF]. There seems to be no way of predicting which walls export properly and which have no outlines. Two walls can be the same wall type, have the same bases and heights, and have the same nearby ceiling types, and yet one wall will export properly, and the other will have no outline.

Of course, exporting with hidden lines removed is not an option -- this causes wall edges to be trimmed in places where a ceiling edge or casework edge overlaps them, and this makes the .DWG a mess if you ever turn a layer off [Hidden Line Removal.GIF]. Supposedly, the wider line always takes precedence over the thinner line, but in practice, this isn’t the way it works. (The green lines in AutoCAD are edges of ceilings, lineweight 1 in Revit, whereas the wall outlines are lineweight 6.) Random walls still disappear, though they are different random walls.

I've tried exporting to both 2004 and 2007 file formats -- no difference.

I've tried using the RCP as an underlay in the floor plan (instead of vice-versa). This works better in that all of the wall lines seem to show up, but the ceiling grids do not. In the export layer settings, the surface pattern for the ceiling is assigned to layer A-CLNG-PATT, but no such layer ever gets created in the DWG file, despite the ceiling grids being visible in the Revit view [Floor Plan.GIF].

If we don't use underlays, we can export the RCP and floor plan separately -- no missing lines result. Then we can insert one DWG into the other as an exploded block, but I am trying to find a less time-intensive, less screw-up-able process.

Has anyone else had this problem? Has anyone come up with a proper solution?


Scott Johnson, Ph.D.
CAD Manager
Richard L. Bowen + Associates

[jcdecastro]

Has anyone else had this problem? Has anyone come up with a proper solution?

I think just about everyone has had this problem/s but no 'proper' solution that i know of...

1. Revit could fix import and export issues
-no more slightly off axis lines when the line is straight in cad and that fix the related 'too far' from 0,0 issue.
-poduce a more clean import from cad that has one text style instead of a text style for each instance of text and one filled region style instead of one for each instance.
-allow revit to export the ceiling

2. MEP can use the two files and or the xref command.

3. MEP can switch to Revit or you suggest to them that they will get less work if they dont

4. Revit can fix ceilings to be component based an not a filled region.

5. Architects can continue to spend time 'fixing' backgrounds and losing the time and money gained from using revit in the first place.

6. We can all go back to AutoCAD...not!

[dbaldacchino]

Have you tried creating a sheet view with two overlayed views and export that? Basically, place a floor plan view and place a ceiling view on top. You can easily snap those two views together....then export that sheet.

[sven.129574]

David, thanks for the idea, but I'm afraid that overlapping views won't help us too much because of the way that Revit exports viewports. We're looking to get a single integrated model-space drawing, preferably without having to export multiple files, insert XRefs, or otherwise "fix" the drawing every time we export.

Of Jose's ideas, naturally I like #1 best. :) Eventually, #3 will happen, but in the meantime, we're probably stuck with #2, unless someone has some less effort-intensive solution.

I've submitted the problem to Autodesk. I figure that at the very least, they should be informed that they lose walls during the export process. But I suspect that we'll still wind up having to exporting two files and XRef them together every time we need to send stuff to engineers.


Scott Johnson, Ph.D.
CAD Manager
Richard L. Bowen + Associates

[Justin Marchiel]

i would say that if they want certain files in a certain way that takes extra time for you to set up or create, tell them it will be a billable item to them from you.

i get the opposite of this all the time, so i would be nice to send it back there way.

just a little venting and sorry it doesn't solve your problem.

justin

[jcdecastro]

Now we have another problem....
Our ceiling grid (pattern) is moving in the exported cad file, the lights are staying in place and the ceiling grid is jumping around. The extends of the ceiling is staying the same but the pattern is moving.

Does anyone know if the latest build of RAC 2008 fixes this?