PSet parameters

[Anonymous]

Hello everyone,

I have to incorporate some attributes into my model.

Here the details:

- the WBS must be incorporated into the pSet with the name "AA", the individual parts of the WBS are to be filled as a separate attribute.

Anyone can help me with that?

PS: is my first time doing that 🙂

Thank you

[RobDraw]

What's a WBS?

What's a pSet?

[Anonymous]

Not completely sure what is being asked but my assumption is. 

You need to add a so called container into a specific type of family ( Wall, Generic Family etz.) which starts with Pset_AA

( While walls and stuff has their own you need a custom one right?) And export it into a IFC and make it viewable in a IFC viewer whatever it is? ) Like the one PsetBuildingXXXSpecific category in the screenshot?

[Anonymous]

Hi Kristof,

Exactly that's what I need to do!

[L.Maas]

@RobDraw 

WBS is work breakdown structure. Term used in quantification (e.g Navisworks)

pSet is a property set. Term used when creating IFCs

@Anonymous 

I think you can add a (project) parameter to your Revit file and hook it up to the different Revit categories.

One way of exporting it to IFC is create a schedule with that parameter and include that schedule in your IFC export

Other way is to create a user defined property set (txt file) and include that in your IFC export

[Anonymous]

Alright ill give you as much as I can as Im working with it now and my knowledge is Work in Progress as well as nobody kinda feels to touch that topic at all for some reason ( IFC sucks lets face it. xD)

First of all you have to find out what the family is exported as when going into IFC ( You should have the IFC Exporter addin for Revit first of all)

1. Find out the Family where it goes when exported to IFC

- In Revit you go to - File - Export - scroll down to Options and IFC Export - There you search for the Revit Category your object is in and into what IFC main container it goes to - As an example for Generic modells its IfcBuildingElementProxy

2. Making the export File you need to make a TXT file which I posted down and there is the formating inside written but ill break it down quickly in a JPG which I posted down too

3. When exporting finally:

- Go to Revit - File - Export - Ifc 

- There now click on Change settings you have to make your own template there go into the tab for Property sets - And there check the first option for user defined property sets there you insert the text file and then it should work

Small troubleshoots I had:

-Definitely need to keep the format as its shown in the Text File I sent you and as is explained up there always keep a TAB between the words else it wont work.

- Some families just dont get containers for some reason I asked that a month ago here nobody answerd so you still would need to figure that out

- And if you got a different syntax in the Notepad TXT file besides Text like a True/False parameter I got no idea how you make that work I tried to use every syntax I found for revit it just doesnt work so I kept all parameters as Text nobody can backtrack it if its a True/fale parameter or a Text one if they dont open it as a revit file and only in a viewer.

[JF.K]

Hi @Anonymous,

I think that first of all one need to understand the basis of how the IFC scheme works and then how one can properly translate your Revit information into IFC (through the IFC exporter as @Anonymous mentioned). All the tips and detailed "how-to's" described in this post are certainly very useful but they won't be of so much value if one doesn't understands the basis behind it.

I had to go through that process as well and these are the websites that helped me out putting all the information together to study the IFC scheme. Then I started to understand how to actually make the Revit IFC export work:

• https://bimblog.bondbryan.co.uk/ --> start with this. There is very nice and enough detailed explanation on how the IFC scheme works.
• https://sourceforge.net/p/ifcexporter/discussion/general/ --> forum for discussion about the IFC exporter developed for Revit. There are a lot of information about IFC entities, Psets, issues while exporting, etc.
• https://standards.buildingsmart.org/IFC/RELEASE/IFC2x3/FINAL/HTML/ --> This is one version of the IFC schema itself (version IFC2x3). Here there is no information how the interaction between Revit and IFC works, but this is the representation of the scheme itself.  You will find everything about its organization and structure (IFC entities, attributes and properties). I found it a good source to dig in while I wanted to explore different IFC entities and studying the blog (first in the bullet list).

It takes some time and study to set up a proper translation from Revit into IFC. But once you get it, you can start developing your own .txt files if you want to make your company specific Psets (property sets).

[Anonymous]

@JF.K Thanks those links are rather useful. Though I have a question that still persists and isnt solved till now maybe you know more? I cant give a topography a custom properties. It is listed under IfcBuildingElementProxy and Pset_BuildingElementProxySpecific is what I want to add but it sadly doesnt add it when its exported as generic element. I have to move it from  IfcBuildingElementProxy  to IfcSite which causes other problems ( Like every topography is now one you cant split it into more pieces)  but it creates the Pset container.

Any idea?

[Anonymous]

Thanks a lot @Anonymous, your instruction are very helpful!!

I have another issue on the 3th point,

when I check the first option for "Export user defined property sets" and I insert the text file, in the end it doesn't export the model but only a text file with this error "EXPRESS Data Manager EXPRESS compiler version 9.8.9B 20130507 diagnostics".

Do you know what could be the issue?

[JF.K]

The Psets are sets of properties predefined in the IFC schema and as far as the documentation for IFC2x3 goes there isn't any reference to that specific property set. You can though create your own custom property set to where you map all your parameters from different Revit categories.

Where I am working at the moment the (country-wide) standard is that everyone should avoid any IfcBuildingElementProxy in their IFC exports. It doesn't represent specifically any type of element in a construction environment and normally is the result of a "direct export" from a Generic Model category ( GM should be then avoided for the sake of information translation for the reason stated above). But that is of course debatable and is directly related with the industry standards.

I just don't understand how you cannot split topography? Do you mean in IFC? If yes, why would you want to split that geometry in IFC?

[Anonymous]

It is asked to give the topography the Pset specific container for various examplar parameters - like its covering how much water it can soak in etz. - And the thing with splitting is if I make now a surface thats pure grass and I need to make a small surface for a stone pavement which includes grass as well but is still part of the topography I just add different values inside the examplar parameters. 

- The issue is if I keep it in the IfcBuildingElementProxy the exporter cant add the subcontainer Pset_BuildingElementProxySpecific but does split to topography as above mentioned.

- If I add the Topography into IfcSite the exporter adds the subcontainer Pset_BuildingElementProxySpecific

but the topography is unified and does not behave as a splitted object but one big surface even if the exemplar parameters themselves are different.

[JF.K]

I am starting to grasp what is your issue but I never had to deal much with topography. Can you post only the topography file here as a .rvt file?

I might have a look when I have some spare time.

[Anonymous]

Sure though it is just a dummy file so you might as well make a own topography but I set a project parameter for the topography itself so yeah here it is. Put my user default TXT file for the test inside a well so you see the squares inside will be kind of plants which work inside the BuildingElementProxy file but the Topography kinda avoids it. 

If you find out anything id be really thankful!

[JF.K]

Hi @Anonymous. Finally I had some time to test your file, and unfortunately I just reached the same conclusion as you.

What I did:

• Created several topography Revit objects with sub-regions and different combinations of IfcExportAs values:
  • IfcBuildingElementProxy
  • IfcGeographicElement (I needed to use the IFC4 schema to get this Ifc entity since it doesn't exist in IFC2x3)
  • IfcSite
  • IfcFurnishingElement
• Created several model in place elements with the same aforementioned combinations of IfcExportAs
• Created a fresh propertysets txt file mapping to all the aforementioned Ifc entities. (I wanted to exclude any previous issues, by creating a new one)

The result:

• The model in place elements behaved as expected so you can map them to different IFC entities (the 4 above worked)
• Topography didn't work at all. As you mentioned as soon as you map it to IfcSite, the geometry becomes one. If you map it to other IFC entities the export doesn't apply any new custom property set. This might be explained by the fact that Topography is a system family and system families are hard-coded and not so flexible when it comes IFC export. You can see the same type of behavior if you try to export a Revit Wall to a different IFC entity that is not IfcWall (it simply ignores the IfcExportAs parameter). Strangely enough (and not consistent at all), the only system family where this behavior doesn't seem to occur is with Revit Floor category (you can for example map it to IfcCovering)

I don't have an answer to your specific issue, but the research made my knowledge about IFC exports a bit wider.

I attached the revit file,  and txt file if you want to check it yourself (unfortunately this forum doesn't support .json and .ifc type files 🤣) .

Merry Christmas!