topic Re: IFC and Meshes in Collaboration with other software

IFC and Meshes

Anonymous — Mon, 05 Oct 2009 19:46:29 GMT

I have been attempting to export slabs/floors created with the mesh tool into IFC but when I try re-introducing them into archicad, they don't show up. If introduced into TEKLA, for instance, they are there to some degree. We have been grappling with this mystery for days now and can't seem to figure it out. I am using Archicad 12 and am running Vista x64. Any help will be greatly appreciated.

Re: IFC and Meshes

Laszlo Nagy — Tue, 06 Oct 2009 11:35:24 GMT

Maybe it is because they were done using the Mesh Tool.
I would be suprised if there was such an intelligence in the IFC Add-ON that even though you create a Mesh, the Add-ON knows that it is really a Slab. Then when you reimport it into ArchiCAD, the Add-ON should know that it now needs to convert it back into ta Mesh.

What if you create the Slabs using the Slab Tool and perform some SEOs on it if some part of it needs to be sloped?

Re: IFC and Meshes

Erika Epstein — Tue, 06 Oct 2009 18:51:43 GMT

Which AC and which IFC?
What do you mean when you say "If introduced into TEKLA, for instance, they are there to some degree. "
Why are you using meshes for floors? Is it for sloping tops as Laszlo suggests?
Did you read the section on meshes in the IFC guide?

Re: IFC and Meshes

Anonymous — Tue, 06 Oct 2009 18:56:51 GMT

I was able to create the sloping slab with the SLAB tool, of course, by employing sloping cutting planes built with the MESH tool. I resorted to SEO with cutting-planes as operators and slab as target; this gave me the sloping slab desired. I then proceeded to turn off the layer of the cutting planes in order to have in view only the sloping slab. This was saved as an IFC and then introduced to both TEKLA and Archicad. The results were the same in both, namely, that the slopes that were cut into the slab with the use of the mesh cutting planes were negated by the IFC process. All that we can see is the original unaltered block of slab.

I am wondering if it is an issue with the SEO, however, when working only with MESH-drawn slabs, and not SLAB-drawn slabs, the SEO are respected by the IFC process and the cutting plane alterations are visible, at least, in TEKLA, though nothing in Archicad as noted in my first post in this thread.

Re: IFC and Meshes

Anonymous — Tue, 06 Oct 2009 19:29:40 GMT

I am running Archicad 12 and, for no particular reason, am using IFC 2x3.

The "to some degree", in reference to the TEKLA import in my first posting, was unnecessary as that part works well.

We design many parking structures and we discovered, by trial and error of course, that it was most practical to model our slabs with the mesh tool since this tool allowed us to mimic the dramatic sloping surfaces more effectively and accurately. To model the sloping underside of slabs, we'll make a copy of the first-modeled mesh, drop it in elevation, and apply a SOE with subtraction as the operation-type. We'll then proceed to hide the layer of the operator mesh and be left with a single mesh with slopes on top and undersides.

I read a section within the IFC Reference Guide making reference to meshes. Unless there is something I missed within this document, I am selecting what appears, to me at least, to make most sense insofar as yielding the results I want; obviously my sense is wrong as this has not worked thus far.

Re: IFC and Meshes

Erika Epstein — Wed, 07 Oct 2009 00:45:07 GMT

What do you have the meshes settings in the IFC translator set to?

Re: IFC and Meshes

Anonymous — Wed, 07 Oct 2009 01:14:40 GMT

My settings for meshes are set to BREP, and have also tried the others. For IFCSite, I have also tried all of them.