BIM Coordinator Program (INT) April 22, 2024

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Collaboration with other software
About model and data exchange with 3rd party solutions: Revit, Solibri, dRofus, Bluebeam, structural analysis solutions, and IFC, BCF and DXF/DWG-based exchange, etc.

archicad to revit structure via ifc with grid

Anonymous
Not applicable
Okay the subject heading says it all. I am trying to learn how to get a common grid between myself and the structural. We are now at 65%
And we still have not sorted this out. Of course when I began this project, I did not know that one cannot all the Project Origin Point in Archicad.

I have exported the ifc model with the optimal translator for REVIT structure. The engineer has installed the plugin to improve ifc import available on the graphisoft website.

I know nothing... about revit. Our structural engineer laments that we do not have revit architectural because coordination would be so much smoother.

I need to get the grid to insert correctly on their drawings. Why would the grid rotate itself and move? Is this an REVIT Structure import problem? or is this an Archicad export problem?

grrrr!!! And why? i will lament, can i not see the grid i export in the solibri viewer.
9 REPLIES 9
Anonymous
Not applicable
kantrolya wrote:
I did not know that one cannot all the Project Origin Point in Archicad.
oops should be "I did not know that one cannot alter the project orig....
owen
Newcomer
Its strongly recommended to agree and share a common grid file early before each consultant charges on with their own models. Trying to reposition multiple models, each with their own origin once you are down the documentation path can be painful.

I have not quite figured out all the details yet, but when exporting from ArchiCAD to IFC the AC Project North is stored in the IFC file. When you view this file in Solibri it will look as it does in ArchiCAD (Project North has no effect), however it appears that when Revit imports the IFC file it reads that Project North setting and rotates the model accordingly to match the Revit True North. That's what is causing your model to be rotated out of position in the Revit file. There is also funny business between the AC Project Origin and Revits origin, the latter is not fixed but can be repositioned to 'real world coordinates' without actually affecting the model location. You basically pick a point and say this is X,Y map grid whereas in ArchiCAD you physically need to move the model relative to the fixed origin.

Given that you are now both using (independently) established locations for your models I think the easiest thing will be for the Structural engineer to reposition your model each time they import into Revit. As long as your IFC file contains the Grid its very quick to reposition a linked file in Revit - only takes a couple of clicks. If you get into the game of actually trying to move one of your models so that the exports align expect to waste a lot of time in trial and error.

Now on to levels ... you are both using exactly the same stories/levels aren't you?
cheers,

Owen Sharp

Design Technology Manager
fjmt | francis-jones morehen thorp

iMac 27" i7 2.93Ghz | 32GB RAM | OS 10.10 | Since AC5
Anonymous
Not applicable
Wow. Thanks for your very informative post Owen. I understand the issue much better now.

Thank you! I spent quite a bit of time trying to sort this out. But I have so little understanding of Revit which is paralyzing to me as I try to be an effective communicator and project leader.

I will try to figure out the north part of the rotation.


I'm glad someone answered, as this is kind of in the:

"this is not archicad's problem, because after all it is revit that isn't playing nice with IFC."

is the sense i'm getting. that said, it does seem like Archicad is bending over backwards to try to make this work, what with a plugin for revit that they produced to improve IFC import. so i imagine it's a touchy subject for some of the people who have spent the last 20 years on archicad...
owen
Newcomer
Another thing the engineer could try is using your exported IFC file to obtain Shared Coordinates (Revit term). I'm by no means a Revit expert but this feature can be used to align several separate models in differing locations to a common project coordinate system. Have not yet tried it with an IFC file (examples are all around DWG/RVT exchange)

owen
cheers,

Owen Sharp

Design Technology Manager
fjmt | francis-jones morehen thorp

iMac 27" i7 2.93Ghz | 32GB RAM | OS 10.10 | Since AC5
Anonymous
Not applicable
I can't even get my grid objects to export to IFC. Am I the only one? Using the AC14 grid tool and tried exporting to IFC with the General Translator. I also tried a duplicate of that to include 2D elements. Both to no avail.
Laszlo Nagy
Community Admin
Community Admin
As far as I know this is a limitation of Revit with IFC.
This is why that Add-In was developed for Revit.
You should install it in Revit Structure.
Then open the IFC in Revit, then run the optimization command of the Add-In and it should bring the grid into Revit.

I think in Chapter 8 of Part 2 of the Collaboration Interactive Training Guide you can find an example of how this works:

http://www.graphisoft.com/education/training_guides/#COL2

PS.: You can install an IFC Viewer like Solibri or BIMSight and check if the Grid is there in the IFC saved from ArchiCAD.
Loving Archicad since 1995 - Find Archicad Tips at x.com/laszlonagy
AMD Ryzen9 5900X CPU, 64 GB RAM 3600 MHz, Nvidia GTX 1060 6GB, 500 GB NVMe SSD
2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac27
Anonymous
Not applicable
hm. this is interesting... well not really. just necessary.

I downloaded a trial version of revit structure. it's really more helpful than the free viewers which don't even show the grid.

anyway. i have another question:

i'm getting the grid through, but unfortunately, it is including the grid elements from Bobrow's Mastertemplate Legends. Is there any way to dis-clude those grid elements from the IFC save-as without deleting the hotlinked "legends" if i figure this out i'll let you know, but i'm curious if anyone has a quick answer to this.

thanks

E
Anonymous
Not applicable
okay, i figured out a way that works. use the heavy marquee to select the area and then do a save as. it kept out the grid of the hotlinked mastertemplate.

i didn't really think that would work because i had the problem with the hotlinked legends grid showing up even when setting up the ifc translator to only export "Visible elements (on all stories)"

but it did.!
Anonymous
Not applicable
Our office uses ArchiCAD for Architecture and Revit MEP 2013 for engineering. We have come up with 3 work-arounds to the grids not working between AC and Revit. They are:

1. Setup 'grid-planes' using the new morph tool. The plane is placed vertically and cuts through the entire building and down through the site. The plane/ morph exports into IFC and then imports into Revit in a consistent location. The Structural/ MEP engineer then needs to add his grid where the grid-plane is located. (Down side is that if the engineer places the grid off of your grid-plane you have a problem)

2. Send an old fashion .dwg file of the grids. Revit can Xref the grids on each view or the engineer can recreate his grid based from your .dwg.

3. (Slightly scary perhaps) Allow the engineer to control the grid and allow AC to hotlink in the grid as a separate file. This would happen after the actual grid scheme is solidified and you (the architect) still have the "control" to tell the engineer to change it if required.

I know these solutions don't actually make the AC grid work in Revit but this is what we have come down to. (I also cannot see the Grid in Solibri 3D but it does show up in the plan setting at the bottom corner and you can turn it on with your "Hide Footprint Controls" at the Top Corner)

I hope this is of some help.

Cheers,

Garth
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