Friday, September 30, 2016

Imported or Linked DWG Appearance as Generic Model Broken in 2017

Using Revit 2017, I have a 3D DWG file for some framing that I want to use as a coordination reference within a project file. Initially I linked the file directly to the project but that approach (unfortunately) doesn't respect the cut plane of a plan view which, for example, means cripples above a header show up in the plan view too (header as well).

I decided I'd use the old create an in-place Generic Model family trick.

If you're with me so far you're probably expecting what I expected; to find that Revit regards this imported 3D geometry as generic model (cuttable) category information, giving me the look I wanted. However, when I clicked Finish Model the linked file disappeared entirely.

I thought for a moment, "Am I just imagining that I could do that? I swear Revit used to do this?!?"

Hmm, I decided I'd create a component Generic Model family instead and use Import CAD. This way I could replace the source CAD file if necessary.and just reload the family later...if necessary. Also thinking, "...maybe it'll work this time, this way...?" Nope...

I gave in, I did a quick search using Revit Help and noticed a result called "Regression Revit 2017 - Cutting 3D DWG with section results in inconsistent model display".

NUTS! least I'm not crazy (about this at least)...

Well I'm writing to declare that it's not just an issue in section views. The damn thing doesn't show up in a plan view at ALL.

It works as I remembered in Revit 2016...project is in 2017 though.

I did try creating the family in 2016 and let Revit upgrade it in the 2017 joy...busted. I also created a Specialty Equipment family (in-place too) and it shows up in plan view but since that category doesn't's missing the point, my reason for traveling this road in the first place.

sigh ... next service pack, update release, patch...(whatever they're going to call...)


Unknown said...

Did you try to make the family a structural column, and under its family category settings unchecked "show pre-cut in plan views"? I don't have Revit in front of me so not sure of wording or if the setting is checked by default. If it is unchecked, then check it.

Bert said...

Very Sad, for such international acknowledged program you'd expect better...
Hope it gets patched soon...

Steve said...

Freddie - Did try that...didn't help either. Bert - Bugs happen in software, inconvenient timing for me in this instance.

Matt Taylor said...

Hi Steve,
I don't do that sort of thing, but I think I know what you mean, and was a little curious.
So I had a try, and it seemed to work okay for me. Things above the clip plane didn't show, and a sloping wall showed different lines when the view range is changed. I had view clipping on.
I used the 'Metric Generic Model Adaptive' family template.
The 3D CAD file had a few 3D solids in it, was in AutoCAD 2010 format, and had originated from a Revit export.
I have Service Pack 2 (for Revit 2017) installed.

I hope one of these notes triggers something and helps you solve the issue. Maybe I misunderstood your workflow?!



Steve said...

Matt ~ Thanks for considering it. I tried exporting my own solids from AutoCAD 2017 to various older versions of DWG to see if that had an impact on how Revit treated solids. The actual file I'm working with is the result of an export from another software product and it yields only solids.

I also experimented with adding lines and other forms to see if something might cause Revit to pay the geometry more respect, in line with what it will do using Revit 2016.

All joy...

At this point I'm stuck's a bug that they've acknowledge in a related context. Until they've sorted that out I don't think I'll be getting that old behavior back.

Matt Taylor said...

Hi Steve,
Sorry to hear you didn't have any more luck.
I just tried it with the 'Metric Generic Model' family and got a valid result, so I'm figuring it's something in your DWG that's causing the issue.
You could try importing the DWG into a new Revit model and then export it to DWG, then put that in your generic model.
Or DXF it (from AutoCAD), then re-save it as a DWG. I haven't tested what that does to 3D solids!

Anyways, good luck.

Dave Baldacchino said...

Audit, purge would also be my first troubleshooting (which I'm sure you've done) although if it's working in 2016, then that won't help probably. Did you verify whether 2017.1 addressed this issue? We don't use this functionality much these days but I remember a few instances where this came in handy.

Steve said...

No change for me regarding the files I'm working with and 2017.1. It does seem to have address the issue for other DWG files though. Autodesk's own post about it acknowledges that the DWG format leaves a lot of room for variables.

It isn't a show stopper in my case. It would just be nice if the cut of the file in a plan view didn't show elements above the cut like it used to be able to do.