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.
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?
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?
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...
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...
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.!
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.!
