IFC export and import - classes, etc.?

[nering]

OK, how do you export the class definitions, like glass opacity, colors, etc.

After I did the IFC export the only classes left were "dimension" and "none".

Does anyone else work with consultants on Revit? How does interchange work out for you?

Also, the stair switches from it's configuration to a single straight run.

Is it better to convert the stair to a group before exporting?

Any advice, tips, etc.?!

The other strange thing: when IFC is imported, the error message "nothing was imported!" shows up. But the model actually did import, albeit all screwed up...

Is that VW's way of saying not everything was imported?

help please... :confused:

Edited September 22, 2009 by nering

[nering]

We work on Macs and neither Revit, nor Bentley are an option.

I am hoping that NNA is dedicated enough to making the 3D/IFC/rvt conversions more seamless and VW more BIMmy

I agree about VW structural though, it could use some improvement. Especially since our engineer can't even open/import the IFC files in his Revit Structure, what's up with that? - although that is a question for AutoDesk...

[Bret]

Our structural firm uses VectorWorks (Fundamentals), although we have one client who is going to require us to get a copy of REVIT Structure. We're not really excited about it, but I have to say that I'm curious to see how REVIT model collaboration will work out, and how it will interact with the analysis software we use.

I'd love to see VectorWorks develop real interaction with RISA/ADAPT/etc. (oh, how I dream of creating layouts in a real drafting/modeling program!), but I don't expect it to happen soon for a couple of main reasons.

First, most structural engineers are using AutoDesk products, so the analysis software companies focus their limited resources on interacting with those products. Second, we engineers are a small minority of VW users, so I don't honestly expect NNA to dedicate too much effort into promoting this either.

Unfortunately, these problems feed off of each other, and I think the only way to get VW (and VW-as-BIM) accepted in a more widespread fashion is for Nemetschek to make a concentrated proactive effort into making these connections.

[Miguel Barrera]

Bret,

Which analysis software do you use and how do you use it in conjunction with VW? Can part or all the analyis be done in VW?

I know that some of the information needed for structural engineering is already in the drawing and is just a matter of extracting the data to do the calculations.

[nering]

Another issue I encountered - ALL the walls exported as walls into IFC, which would have been great if not for the fact that they all are 6" thick, regardless of original thickness!

And I used the VW wall styles. Should they have been "un-styled" walls?

Anybody else has had a similar experience? what did you do to fix it?

[nering]

Any suggestions on what to do with the walls and their thickness? Anybody?

[Kool Aid]

Walls are exported OK, but when imported into VW all walls become 150 mm thick.

(Whether that is 6", I wouldn't know. Maybe it is and maybe that is the only wall thickness used in Maryland. Anyway, you shoud NOT use VW for testing of IFC-exports as the import facilities are shockingly bad. Use the free Solibri Model Viewer instead.)

[nering]

150 mm is pretty much the same as 6". People in Maryland must get awfully cold between those thin walls

Thanks for the tip, I tried Solibri Viewer - the walls did retain their thickness, components, etc. Hopefully it will work out for our consultants in Revit MEP...

[nering]

The IFC export/import in VW2009 summed up issues I have encountered so far:

-The stairs default to straight run regardless of their original configuration,

-The glass loses transparency,

-The walls all default to 6" thickness, (but seem to show up fine in Solibri...)

-Ceilings disappear,

-Spaces between columns get filled with walls,

-All classes disappear.

Bottom line - we have a fully drawn 13-story model that does not seem to work very well.

I wonder if anyone works with both Revit and VW? Is the Revit IFC import as problematic as VW IFC import?

[Kool Aid]

The IFC export/import in VW2009 summed up issues I have encountered so far:

-The stairs default to straight run regardless of their original configuration,

-The glass loses transparency,

-The walls all default to 6" thickness, (but seem to show up fine in Solibri...)

-Ceilings disappear,

-Spaces between columns get filled with walls,

-All classes disappear.

Bottom line - we have a fully drawn 13-story model that does not seem to work very well.

IFC is not supposed to be a design-orientated protocol, so transparencies and VW's ?classes? can't be expected to be supported.

The disappearance of ceilings is interesting: I have not tested NNA's ceiling but my own ceiling object is, in VW 2010, exported very badly. It does not actually disappear, except visually. It is there, but you can't see it. Maybe the same applies to NNA's one? It very well could: the translator, when encountering a ceiling, does not know how to act.

I wonder if anyone works with both Revit and VW? Is the Revit IFC import as problematic as VW IFC import?

If your stuff is OK in Solibri, you're a lumberjack. If Revit does not read IFC: what, you worry? Get them to buy professional software?

[Jeffrey W Ouellette]

The IFC export/import in VW2009 summed up issues I have encountered so far:

-The stairs default to straight run regardless of their original configuration,

-The glass loses transparency,

-The walls all default to 6" thickness, (but seem to show up fine in Solibri...)

-Ceilings disappear,

-Spaces between columns get filled with walls,

-All classes disappear.

Bottom line - we have a fully drawn 13-story model that does not seem to work very well.

I wonder if anyone works with both Revit and VW? Is the Revit IFC import as problematic as VW IFC import?

Without looking directly at the file/project in VW and IFC format, I can only provide the following answers:

1. The stairs SHOULD NOT be changing at export. This may be a bug in the particular version you are using. I have not see this result myself.

2. Right now, IFC import/export implementation for ALL vendors doesn't support colors or textures, as there has not been clear guidelines or implementers agreements to support this exchange requirement. IFC can technically support it, though it isn't easy. Today, IFC compatible application set their own color schemes, if any, for IFC files on import.

3. The walls losing thickness at export from VW shouldn't happen. And they should show correctly in Solibri. The results importing back into VW, though, is a bug, and a serious one. We'll have to file a bug report and get on it.

4. How have you created your ceilings? They need to have IFC Data attached to them to be exported. If you use the Floor command, or simply use an extruded plane, select the object, then select the "IFC Data..." command from the AEC menu. When the dialog appears, select the "IfcCovering" entity from the list. In the next dialog, select the checkbox, "Use standard properties for this symbol." Then select the IfcCovering in the list below and scroll down and select "Predefined Type". From there select the pulldown that appears at the bottom of the dialog and select "CEILING". Choose OK to exit the dialog. The ceiling should export correctly.

5. I'm not sure what you mean by "Spaces between columns get filled with walls". I'd have to see it first.

6. Classes don't get transferred. Again, this is a technical and implementation issue. There is currently a request to maintain "Layer Names" for objects at export(AutoCAD-centric, but we all know they are Classes in VW). We'll see where this goes in the international standards body over the next year.

I am available online/offline to all users regarding IFC import/export issues. I can help examine and troubleshoot files, as well as locate implementation issues and get them filed as bugs and resolved.

I want everyone to learn the best use of VW to get the best results and understand the limits of IFC, in general, but also be aware of the capabilities. Also understand the capabilities of other Applications is important when using IFCs. I personally do testing against our competitors products and other products that our users may be inclined to exchange information with.

In the Autodesk 2010 application family, Revit was the least compentent import performer. AutoCAD Architecture and NavisWorks did the best, nearly perfect, with a complex VW model.

This thread has illustrations of results from various applications:

http://techboard.nemetschek.net/ubbthreads/ubbthreads.php?ubb=showflat&Main=26247&Number=126141#Post126141

[Kool Aid]

3. The walls losing thickness at export from VW shouldn't happen. And they should show correctly in Solibri. The results importing back into VW, though, is a bug, and a serious one. We'll have to file a bug report and get on it.

Well, it doesn't happen at export, only at import, rendering VW totally useless in terms of interoperability.

[nering]

Can anyone post a screen shot of what it looks like when IFC export is in progress?

Mine is just blank and non-responsive. VW2009 if possible.

[Jeffrey W Ouellette]

Natalie,

At export, VW will not be responsive. A small "empty" dialog 'Export IFC' should appear in the middle of the screen after you say OK to the main export dialog.

Behind the little dialog, the model (hopefully in Top/Plan view) will be constantly refreshing on the screen as the export works its way through the model.

Depending on the size of the model, this will take a long time. The export translates the geometry and data for each storey/level into separate temporary files, then combines them into a single IFC model file at the end.

The model I received from you earlier and examined might take no less than 20 min. to export. I've got larger models that take 40 min. and smaller models that take 1.

[nering]

Natalie,

The model I received from you earlier and examined might take no less than 20 min. to export. I've got larger models that take 40 min. and smaller models that take 1.

Now, that makes me sad - it takes my machine about 2 - 2.5 hours to go through each floor. And, VW crashes after floor 10 or 13 - just a few storeys short of finishing.

Maybe I'm doing something wrong.

But the export process looks exactly the way you described - blank IF export window (would be cool if it showed progress bar) with the plans being refreshed all the time.

[Jeffrey W Ouellette]

Whoa. It shouldn't take that long. At least not the model I saw.

I keep hoping for a working Progress Bar, too.

Natalie, you need to file a bug (see the link under the VW Community Links menu to the right). You can send the file to bugsubmit@nemetschek.net.

We'll get the engineer's attention and see if there is something simple wrong, or not.

In the meantime, you can send the updated file to me via YouSendIt.com, again, and I can try to take a look at it in its current state.

[nering]

Jeffrey,

I sent you the file, let me know if you get the same problems.

I am still having issues with the floors and ceilings (converted to IFC entities) - they just won't export correctly.

And, how do you draw soffits so they export well?

I used short walls, with start Z at the height I needed, but they all ended up "sitting" on the floor after IFC export.