We use Revit MEP and working with and architect who uses Archicad and for the import we use the improved import-tool from Graphisoft.
For testing, we got two different IFC-Files in one all the elements have the “Brep” setting and in the other “Extruded/revolved”. I found out that all elements with Brep are imported as In-Place-Families and all the parameter are lost so this export option is out of question. Importing the second one most of the walls and doors etc. matching with Revit walls and doors but I do get a lot of error messages like “the element has a short segment that can’t be fixed” (paraphrased translation from German) or “overlapping elements” like walls where the architect said that there is just one wall.
What does short segment mean and how can we avoid it?
Is this a problem because of wrong export-settings?
But the biggest problem we do have with Curtain Walls, they always are imported as an In-Place-Family and Revit and the programs we are testing for heat and cooling calculation have issues with them. They are not recognized as a wall or curtain wall element.
I have overwrote in the import options under the “IFC-Curtain-Wall” parameter to match with the respective Revit-Category of curtain wall. But it always comes in as an In-Place-Family and with the elements set to frame construction.
Has overwriting in import option any effect?
Any tips for better importing an IFC are highly appreciated
huck
PS: We are working with the German Revit and sorry for my English.
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The IFC implementation of curtain walls is very dissimilar to the Revit one. In Revit, we have families for panels and mullions based on grid lines on a base wall. In IFC, you get the geometry of panels and mullions independent of any base structure. Trying to convert that into a "real" Revit curtain wall is extremely difficult and would involve a lot of guessing.
The short segment issue may be based on different tolerances in ArchiCAD and Revit - we don't like line segments that are fractions of millimeters long. That could be a case of remodeling in ArchiCAD to get better results.
The main question, though, is - do you need editable elements in Revit, or are you just referencing the ArchiCAD model? If it is just for reference, have you tried Link IFC instead?
Regards,
Angel
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I quickly tried to Link the IFC file but then there can no Spaces be placed. So yes we need the IFC-File to be imported with editable Revit-Families. In-Place-Families right know don’t work with Revit’s Energy Analysis and also not with the external programs for Heat and Cooling Calculations. That’s the biggest problem and if we cannot use the architect’s model to get the building data we would lose the big benefit of the 3D-model and the “BIM”.
So the only way would be to remodel the curtain wall in Revit?
--
The architect needs to work much more cleaner to avoid the short segment error? Is the result of this error leading to the next error that elements can’t be stay connected? Some are not imported at all.
But what about the duplicated walls – where are they coming from?
best regards
huck
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You should be able to place spaces if you are using 2015 R2 and you set the Revit (IFC) link to be room bounding. That would solve part of your issue but not all of it.
Unfortunately, that seems to be the workaround for now. I am going to pass around your email as a workflow that we don't currently support well to see what improvements we can make.
As far as duplicate walls - I'd have to see the IFC file - it is hard to know if that's a user error, an export error or an import error. One thing is if you check in the Link IFC, if you see the same thing as in the Open IFC, then it is likely in the IFC file and an export error. If the Link IFC looks great and the Open IFC looks bad, then it is likely an import error and we'd have to see the file.
Regards,
Angel
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I will take a look at your suggestions and will take a look at the IFC-file and come back later.
edit:
ad1: it works, but the time to set up the space-separators is time consuming and the information of room bounding objects like walls and windows etc... is lost.
ad3 I have linked the file and it looks good and the open (imported?) ifc file looks really bad - walls missing. see attachments.
Yes, Open IFC = the imported version. Note that those blocks in the linked file are the openings for the doors - they can be turned off. Also, if you don't see a 2D representation, it is likely because it wasn't in the file - we don't yet create "default" 2D representations from link - it is intended to accurately reflect what is in the IFC file only at the moment.
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We had a meet up with the architect and well his 3D-model contains all the duplicated walls and other errors. We will get a new cleaned up version next week.
You said, if the linked IFC-file looks fine and the open one is messed up, than it is probably an import problem. The missing walls still may a problem of import? Well, I will come back to you, if this problem still occurs in the new IFC-File – if I may?
Regards,
huck
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Yes, it is still very possible that there is an import error. So missing walls may be on the import side. If you see it in Link or other browsers, please send us the file so we can replicate the issue. However, as you noted, many issues could be modelling or export issues also.
Regards,
Angel
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I’d like to come back to this topic. Project-changes and other things have been slowing down the process – the usual problems :-).
We received two IFC-Files, the only difference was that in the first one the geometry was exported as “complex profile” and in the second as “building element parts”. We now found an export-setting that nearly works but there are some problems and questions.
First it only works with extruded / revolved and without junctions. If you have extrude / revolved with junctions all elements that has junction will be imported as inplace-famlies and they are useless for calculation and analysis.
But there seems to be a difference between complex profile and “building element parts” as well, because when we import the complex-profile-IFC a lot of elements are missing like the structure work. Spaces are ignored or their borders completely different and are very strange compared to the IFC-File. Importing the “building element parts-IFC” the whole geometry is imported the missing objects are Inplace-families but also walls that are Revit-walls in the other IFC-file. But Spaces are get messed up also. (See pictures)
What’s the difference between this two options complex and building parts except the file size?
Then I got a lot of error-messages concerning that junctions cannot be hold up, short line and so on (paraphrased translation). Is this due the difference of modelling of junctions between floors and walls in ArchiCAD and Revit? Are there any?
I think there are import problems I don’t know to fix.
Hi Huck. May I ask you if you have found a solution with Space problems after updatering IFC from architect? We are struggling with exactly the same issue. Though we are using Revit 2017.2.3 og Archicad 20 (build 5025) looks like problem is still there.
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There are definite limitations to how much intelligent geometry Revit can create from Open IFC. We plan to address as much of that as we can when we move to open source for Open IFC; some of it will be so difficult that it might not be practical (like trying to create a Revit curtain wall from an IFC curtain wall).
Now, if there are elements completely missing, or the geometry is incorrect, that's a bigger issue. If you can share IFC files with us, that would be the best route. Alternatively, if you can do a Link IFC operation, you can see if (1) is any data missing, and (2) is there anything interesting in the HTML log file? That could at least give us some hints in lieu of the IFC file.
Regards,
Angel
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Thank you for your quick reply. The problem with the curtain wall is in matter of fact a way how the architect modeled it. He didn’t use any curtain wall elements of ArchiCAD instead he used a lot of the thing that’s called morph.
Some of the wall within "complex-profile"-IFC is not correct and the nearly all columns are missing. I tried to link the files but the IFC with building elements cannot be linked. Revit stops.
The pic shows the linked “complex profile”-IFC and there are some columns you can recognize them by the cross and compared to pics above you can see incorrect walls on the right side of the WC.
How can I give you the two files? They are really huge one has ca. 175MB and the other ca. 365MB with the A360? It takes more than two hours to open them.
I would provide the HTML - File as well but thats all in German.
I work on both ArchiCAD and Revit so might be able to help out a little
If the architect has used Complex Profile Walls in ArchiCAD there is no way to get these into Revit as anything other than In-place Walls .. AFAIK this is just a limitation with the current methods available for creating walls in Revit.
In ArchiCAD a Complex Profile is a profiled material (or assembly of profiled materials) extruded along a reference line. These can be used for Walls (along wall ref. line) or Beams and Columns (along axis).
Whilst the later (profiled Beams/Columns) generally do make it into Revit as native editable elements (unless using multiple materials), walls just don't play with Revit which i believe is because Revit cannot create walls from a profile extrusion without modelling in-place. You can sweep a profile ON a wall, but not create the wall itself from a profile.
Digging into the export of profiled walls from ArchiCAD a little further there are two options - as 'Complex Profiles' or as 'Building Element Parts'. The former will simply export the wall as a profile(s) extrusion with a single material, whilst the latter will 'explode' the wall into series of material profiles within the wall 'container'. The main reason for doing this is to retain material colors through IFC and for scheduling of skins.
There are also the 'Extruded' and 'Extruded without Junctions' options - unfortunately which option to use somewhat depends on the purpose of the IFC export and ArchiCAD version being used.
If they are using ACv17+ if you go with 'Extruded without Junctions' you will get non-profiled walls within Revit as native walls and they will use Revit's own logic to resolve junctions. However profiled walls will be in-place and will not connect - you'll probably have overlapping geometry rather than a mitred corner.
If you use the 'Extruded' (with Junctions by implication) option then you will get intersections at all corners, however most of the walls will be in-place, including simple single-skin walls in some instances. From ACv17 onward these junctions will also not be mitred but 'stepped' due to the Building Material intersection logic introduced in that version. I've also noticed that this method actually seems to result in more 'missing' geometry when opening in Revit (Linking is OK however).
So as there are a number of ways to create walls in ArchiCAD the best options for exporting IFC to Revit are variable and unfortunately whatever is selected is not going to cover all the walls, unless of course you put a ban on using 'Complex Profiles' for walls...
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Hello Owen,
Thank you for your detailed and interesting answer. We also came to the conclusion that problems come from the different ways to model.
There seems also a different in the joints between floors and walls. In ArchiCAD the wall height is to top edge of the floor and has an offset from the finished floor level (I hope I do have the right technical terms here) and the joints will be made automatically because the floor has a higher priority than the wall – this at least what the architects told me. In Revit however, what I have seen, most use a level for the lower level of the floor and connect the wall height there so there is no intersection between floor and wall. Am I Right?
So the Architect modeled the wall from the top edge of a level to the next one. Then he has to set the Export to “Complex Profile” with “Extruded without Junctions”. Otherwise all the elements with intersection will be cut see pics for better explanation. The only difference in the export settings is the option with or without junctions. As you can see with junctions the walls got cut in a very wrong way and without junctions all the Elements are native Revit elements.
So we get best result with the Export settings: Multi-skin complex geometries set to Complex Profile and the Elements with junctions set to Extruded/revolved without junctions. By the way the file size is much smaller than with any other option.
But there are some import problems, first I thought that the columns are missing then I found out they are lying on top of each other in the ground level. So it would be nice if someone from Autodesk can take a look at the files.
At Angel: would this be possible?
Thanks again Owen for the inside, it is really helpful.
Hello,
We use Revit MEP and working with and architect who uses Archicad and for the import we use the improved import-tool from Graphisoft.
For testing, we got two different IFC-Files in one all the elements have the “Brep” setting and in the other “Extruded/revolved”. I found out that all elements with Brep are imported as In-Place-Families and all the parameter are lost so this export option is out of question. Importing the second one most of the walls and doors etc. matching with Revit walls and doors but I do get a lot of error messages like “the element has a short segment that can’t be fixed” (paraphrased translation from German) or “overlapping elements” like walls where the architect said that there is just one wall.
What does short segment mean and how can we avoid it?
Is this a problem because of wrong export-settings?
But the biggest problem we do have with Curtain Walls, they always are imported as an In-Place-Family and Revit and the programs we are testing for heat and cooling calculation have issues with them. They are not recognized as a wall or curtain wall element.
I have overwrote in the import options under the “IFC-Curtain-Wall” parameter to match with the respective Revit-Category of curtain wall. But it always comes in as an In-Place-Family and with the elements set to frame construction.
Has overwriting in import option any effect?
Any tips for better importing an IFC are highly appreciated
huck
PS: We are working with the German Revit and sorry for my English.
Hi Huck,
The IFC implementation of curtain walls is very dissimilar to the Revit one. In Revit, we have families for panels and mullions based on grid lines on a base wall. In IFC, you get the geometry of panels and mullions independent of any base structure. Trying to convert that into a "real" Revit curtain wall is extremely difficult and would involve a lot of guessing.
The short segment issue may be based on different tolerances in ArchiCAD and Revit - we don't like line segments that are fractions of millimeters long. That could be a case of remodeling in ArchiCAD to get better results.
The main question, though, is - do you need editable elements in Revit, or are you just referencing the ArchiCAD model? If it is just for reference, have you tried Link IFC instead?
Regards,
Angel
Hello Angel,
Thank you for your answer.
I quickly tried to Link the IFC file but then there can no Spaces be placed. So yes we need the IFC-File to be imported with editable Revit-Families. In-Place-Families right know don’t work with Revit’s Energy Analysis and also not with the external programs for Heat and Cooling Calculations. That’s the biggest problem and if we cannot use the architect’s model to get the building data we would lose the big benefit of the 3D-model and the “BIM”.
So the only way would be to remodel the curtain wall in Revit?
--
The architect needs to work much more cleaner to avoid the short segment error? Is the result of this error leading to the next error that elements can’t be stay connected? Some are not imported at all.
But what about the duplicated walls – where are they coming from?
best regards
huck
Hello,
OK, a couple of things then:
Regards,
Angel
Hello,
thank you for your quick response.
I will take a look at your suggestions and will take a look at the IFC-file and come back later.
edit:
ad1: it works, but the time to set up the space-separators is time consuming and the information of room bounding objects like walls and windows etc... is lost.
ad3 I have linked the file and it looks good and the open (imported?) ifc file looks really bad - walls missing. see attachments.
best regards,
huck
Last edit: huck 2015-03-18
Yes, Open IFC = the imported version. Note that those blocks in the linked file are the openings for the doors - they can be turned off. Also, if you don't see a 2D representation, it is likely because it wasn't in the file - we don't yet create "default" 2D representations from link - it is intended to accurately reflect what is in the IFC file only at the moment.
Hello Angel,
thank you for the explanation.
We had a meet up with the architect and well his 3D-model contains all the duplicated walls and other errors. We will get a new cleaned up version next week.
You said, if the linked IFC-file looks fine and the open one is messed up, than it is probably an import problem. The missing walls still may a problem of import? Well, I will come back to you, if this problem still occurs in the new IFC-File – if I may?
Regards,
huck
Hello,
Yes, it is still very possible that there is an import error. So missing walls may be on the import side. If you see it in Link or other browsers, please send us the file so we can replicate the issue. However, as you noted, many issues could be modelling or export issues also.
Regards,
Angel
Hello,
I’d like to come back to this topic. Project-changes and other things have been slowing down the process – the usual problems :-).
We received two IFC-Files, the only difference was that in the first one the geometry was exported as “complex profile” and in the second as “building element parts”. We now found an export-setting that nearly works but there are some problems and questions.
First it only works with extruded / revolved and without junctions. If you have extrude / revolved with junctions all elements that has junction will be imported as inplace-famlies and they are useless for calculation and analysis.
But there seems to be a difference between complex profile and “building element parts” as well, because when we import the complex-profile-IFC a lot of elements are missing like the structure work. Spaces are ignored or their borders completely different and are very strange compared to the IFC-File. Importing the “building element parts-IFC” the whole geometry is imported the missing objects are Inplace-families but also walls that are Revit-walls in the other IFC-file. But Spaces are get messed up also. (See pictures)
What’s the difference between this two options complex and building parts except the file size?
Then I got a lot of error-messages concerning that junctions cannot be hold up, short line and so on (paraphrased translation). Is this due the difference of modelling of junctions between floors and walls in ArchiCAD and Revit? Are there any?
I think there are import problems I don’t know to fix.
Sincerely huck
Hi Huck. May I ask you if you have found a solution with Space problems after updatering IFC from architect? We are struggling with exactly the same issue. Though we are using Revit 2017.2.3 og Archicad 20 (build 5025) looks like problem is still there.
Hi Huck,
There are definite limitations to how much intelligent geometry Revit can create from Open IFC. We plan to address as much of that as we can when we move to open source for Open IFC; some of it will be so difficult that it might not be practical (like trying to create a Revit curtain wall from an IFC curtain wall).
Now, if there are elements completely missing, or the geometry is incorrect, that's a bigger issue. If you can share IFC files with us, that would be the best route. Alternatively, if you can do a Link IFC operation, you can see if (1) is any data missing, and (2) is there anything interesting in the HTML log file? That could at least give us some hints in lieu of the IFC file.
Regards,
Angel
Hello Angel,
Thank you for your quick reply. The problem with the curtain wall is in matter of fact a way how the architect modeled it. He didn’t use any curtain wall elements of ArchiCAD instead he used a lot of the thing that’s called morph.
Some of the wall within "complex-profile"-IFC is not correct and the nearly all columns are missing. I tried to link the files but the IFC with building elements cannot be linked. Revit stops.
The pic shows the linked “complex profile”-IFC and there are some columns you can recognize them by the cross and compared to pics above you can see incorrect walls on the right side of the WC.
How can I give you the two files? They are really huge one has ca. 175MB and the other ca. 365MB with the A360? It takes more than two hours to open them.
I would provide the HTML - File as well but thats all in German.
Sincerely huck
Last edit: huck 2015-05-20
Hi Huck,
I work on both ArchiCAD and Revit so might be able to help out a little
If the architect has used Complex Profile Walls in ArchiCAD there is no way to get these into Revit as anything other than In-place Walls .. AFAIK this is just a limitation with the current methods available for creating walls in Revit.
In ArchiCAD a Complex Profile is a profiled material (or assembly of profiled materials) extruded along a reference line. These can be used for Walls (along wall ref. line) or Beams and Columns (along axis).
Whilst the later (profiled Beams/Columns) generally do make it into Revit as native editable elements (unless using multiple materials), walls just don't play with Revit which i believe is because Revit cannot create walls from a profile extrusion without modelling in-place. You can sweep a profile ON a wall, but not create the wall itself from a profile.
Digging into the export of profiled walls from ArchiCAD a little further there are two options - as 'Complex Profiles' or as 'Building Element Parts'. The former will simply export the wall as a profile(s) extrusion with a single material, whilst the latter will 'explode' the wall into series of material profiles within the wall 'container'. The main reason for doing this is to retain material colors through IFC and for scheduling of skins.
There are also the 'Extruded' and 'Extruded without Junctions' options - unfortunately which option to use somewhat depends on the purpose of the IFC export and ArchiCAD version being used.
If they are using ACv17+ if you go with 'Extruded without Junctions' you will get non-profiled walls within Revit as native walls and they will use Revit's own logic to resolve junctions. However profiled walls will be in-place and will not connect - you'll probably have overlapping geometry rather than a mitred corner.
If you use the 'Extruded' (with Junctions by implication) option then you will get intersections at all corners, however most of the walls will be in-place, including simple single-skin walls in some instances. From ACv17 onward these junctions will also not be mitred but 'stepped' due to the Building Material intersection logic introduced in that version. I've also noticed that this method actually seems to result in more 'missing' geometry when opening in Revit (Linking is OK however).
So as there are a number of ways to create walls in ArchiCAD the best options for exporting IFC to Revit are variable and unfortunately whatever is selected is not going to cover all the walls, unless of course you put a ban on using 'Complex Profiles' for walls...
Hello Owen,
Thank you for your detailed and interesting answer. We also came to the conclusion that problems come from the different ways to model.
There seems also a different in the joints between floors and walls. In ArchiCAD the wall height is to top edge of the floor and has an offset from the finished floor level (I hope I do have the right technical terms here) and the joints will be made automatically because the floor has a higher priority than the wall – this at least what the architects told me. In Revit however, what I have seen, most use a level for the lower level of the floor and connect the wall height there so there is no intersection between floor and wall. Am I Right?
So the Architect modeled the wall from the top edge of a level to the next one. Then he has to set the Export to “Complex Profile” with “Extruded without Junctions”. Otherwise all the elements with intersection will be cut see pics for better explanation. The only difference in the export settings is the option with or without junctions. As you can see with junctions the walls got cut in a very wrong way and without junctions all the Elements are native Revit elements.
So we get best result with the Export settings: Multi-skin complex geometries set to Complex Profile and the Elements with junctions set to Extruded/revolved without junctions. By the way the file size is much smaller than with any other option.
But there are some import problems, first I thought that the columns are missing then I found out they are lying on top of each other in the ground level. So it would be nice if someone from Autodesk can take a look at the files.
At Angel: would this be possible?
Thanks again Owen for the inside, it is really helpful.
Regards huck