Workflow for import / export with industry standard formats

[boatingcow]

Hi there, I'm still getting to grips with what the IFC file format is (and is supposed to be), but in the meantime, I'd still like to create complete architectural models and the documentation to accompany them. Forgive me if I'm missing something completely obvious, however, I'm struggling to work out the best work-flow for two scenarios:

Scenario 1) I have a complex MEP, structure and mechanical model which needs a 'building' and some architecture to wrap around it. At the moment, I create my mechanical parts in Inventor. I then export a 3D DWG solid model and a 2D plan drawing. I import the 3D DWG to an ArchiCAD 'object' and replace the ugly 2D mesh representation with the 2D DWG plan drawing.

However, I'm still left with an ugly triangulated mesh object in my sections and 3D views, at which the clients invariably point and laugh and ask why I'm using 'beginner' software!

Scenario 2) I already have some architecture and I'd like to design my complex MEP, structure and mechanical parts to fit within it. At the moment, I export a partial model of my ArchiCAD building to 3DS. I then open it up in Rhino and perform a MeshToNurbs which helps me clean up the triangulations into Nurbs surfaces. Then I import the Nurbs model via STEP format into Inventor, after which I can use it as reference geometry.

However, ArchiCAD's curved surfaces remain horribly faceted and I'm left with an incomplete architectural model as I have to use the above process to get the mechanical parts back into ArchiCAD!


I'm just moving to ArchiCAD 16 and I thought I might be able to import a CAD format which allows me to retain the original surface geometry - not just polygon mesh representations.

• Is at all possible to translate an industry standard format like STEP or IGES into ArchiCAD? If so, how do you do it?
• Or, does IFC promise this type of interoperability? I read with enthusiasm that IFC uses the STEP file format.
• Failing all the above, can anyone recommend a 3rd party program which will read STEP/IGES etc and allow me to create an 'acceptable' model for use within ArchiCAD?

I haven't been able to work out why some of ArchiCAD's complex native objects are all beautifully smooth and are lightning-quick in the 3D window, yet my lowly mechanical model looks like an ugly duckling and sucks up 75% of my machines resources just to look at a section...

Thanks for your suggestions.

(ArchiCAD 16 64bit on PC)

[Anonymous]

IFC is a derivation from STEP, although few implementations have implemented more capable shape representations other than "coordination" extrusions and faceted objects.

It depends a little on the nature of your model, but if you're using Rhino to generate STEP (and the IFC generated by Archicad isn't using primitive faceted shape representations) then you can try my IFC importer for Rhino.
http://geometrygym.blogspot.com/search/label/IFC for an intro and you can download from http://www.geometrygym.com/downloads Then you can export to STEP as per normal.

I can't really help at the moment for Inventor to Archicad (potential I could develop an addin there). I do know there are also flavours of DWG export from Revit and the default is mesh reps rather than ACIS solids. Perhaps it's worth checking the options?

Hope it helps, happy to advise further,

Jon

[Laszlo Nagy]

Regarding the 3D DWG Import to ArchiCAD: After you imported the geometry. you can take those faceted Objects and convert them to Morphs. Then you can control the visibility of any edge in the Morph, making them invisible if you need to (Hidden edges).

[boatingcow]

Jon - your plugins look interesting... It does beg the question, should the onus be on generic 3D software vendors (like yourself or McNeel) to implement IFC support, or should ArchiCAD just be able to import generic formats and 'convert' them to BIM models?

For Inventor to ArchiCAD, DWGs are exported fine (solid geometry) but ArchiCAD's translator seems to convert them to meshes on import.

Laszlo - thanks for the tip. However, ArchiCAD almost refuses to convert my simple models to morphs with a dialog warning: "The morph(s) being created are extremely complex and involve a large number of polygons..." I'm not sure it would handle the larger models!

[David Maudlin]

boatingcow wrote:
However, ArchiCAD almost refuses to convert my simple models to morphs with a dialog warning: "The morph(s) being created are extremely complex and involve a large number of polygons..." I'm not sure it would handle the larger models!

I've run into this warning when converting SketchUp and 3DS files imported as Objects into Morphs, and the translation went fine, the Morphs did not slow done my system. So give it a try, I think it is just a generic warning.

To expand on Laszlo's advice: select the entire Morph and change the Edge Type from Hard to Hidden, I've gotten good results using this to remove the extra triangulation lines from an Object imported from SketchUp.

You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.

David

[Laszlo Nagy]

Yes, I second that: probably that warning always comes if the number of polygons is above a certain limit. But the Morph Tool may be able to handle it fine.

[Anonymous]

Hi - I read your thread with interest as I need to import an Inventor model into Archicad. Did you develop an addin to help with this?
thanks!