Correcting IFC position

edited January 2022 in General


Hi, I have received many of these IFCs that are off-center and levitating, this was not the intention of the designer. What is the 'best practice' way to correct this? Can I do this within BlenderBIM and save the fixed IFC?
I suspect this is more complicated than it appears

Comments

  • How accurately do they have to be moved?
    Can't you just press G->(X, Y or Z direction) and export it to IFC again?

  • Hi @Coen when I tried that the origin point(s) moved, I think that is not a good thing

  • Could you share the .ifc file with us?

  • I have attached one of the levitating IFCs
    in addition, can anyone suggest a rationale for why everything is an IfcBuildingElementProxy?
    Keen to hear all comments about the attached as it will help scoping future deliverables from contractors

  • @Nigel said:
    I have attached one of the levitating IFCs
    in addition, can anyone suggest a rationale for why everything is an IfcBuildingElementProxy?

    The native software is not capable of exporting a good IFC I think?. However I was eager to test drive the BlenderBIM add-on with my own add-on. What I did was filter all the IfcBuildingElementProxies in a spreadsheet and list them by the information I had. I used BlenderBIM to assign them all a new IfcProduct.

    Making a new IFC export with BlenderBIM worked like a charm with almost each element assigned a new IFC Class

    I've attached this modified IFC file to this post.

    Keen to hear all comments about the attached as it will help scoping future deliverables from contractors

    I don't know the situation in New Zealand, but in the Netherlands there is an active initiative called the ' BIM Basis ILS' or 'BIM Basis IDS' in English. The one thing which is quite unique is that this initiative is not stimulated by the government. But comes from the sector itself. People who work at architectural offices, contractors and structural engineers, MEP engineers, suppliers organize meetings twice a year to discuss standardization in IFC models. Which resulted in a very simpe two A4 papers in which the standards is described.

    So I took one aspect of this which if often overlooked. That's from the start of a project where to model the 0-point.
    I've modelled a cube in your model which I placed on the 0-point. In Blender BIM that's where the X and Y intersect obviously

    In BimCollabZoom there is an option to show the model origin.

    The reason it's a very simple cube so it's very easy to align multiple models in software like Autodesk Navisworks for example.
    Hope these are the answers you are looking for.

    magicalcloud_75
  • Thank you @Coen for your reply.
    I am really interested in reading the BIM Basis ILS. In Aotearoa NZ we have no national BIM standards for Housing, I think housing, especially state-owned social housing warrants some specific BIM standards. I work for Kāinga Ora (central government social housing provider), we are trying to understand how to use BIM for ourselves. We own quite a few houses and keep them for decades as well as building several thousand new houses a year. Our portfolio is mainly standalone and duplex typologies. However, now we are building at a greater density with more three level walkups and apartments being added to our portfolio. So, anything I can learn about how other countries are doing things the better.

    Coen
  • @Coen You gotta love a 2-pager that spells out in simple language a set of ideals, this BIM Basis ILS will be especially useful as we get back into discussions on BIM implementation in the new year. Thank you

    Coen
  • Although in theory you could take all objects and simply grab them and move them to a new location, there is usually a better way (and usually, you want to rarely shift the entire model).

    You can use the OffsetObjectPlacements IfcPatch recipe, which allows you to specify an X, Y, Z, and angle displacement for the model.

    Also worth learning about is how geolocation is meant to work. There isn't anything inherently wrong with having an absolute origin which is off to one side or the building floating (which usually represents the real life elevation of the project, which is usually a bit above sea level).

    Coen
  • Hi @Moult & @Coen the IFC is one of many (hundreds) standard house designs our organisation has. They could be placed on any site and hence at different elevations. For this reason, I would like to change the IFC's origin to 0,0,0.

  • @Nigel sure, so just use the IfcPatch recipe and specify an XYZ which would move the house design towards 0,0,0.

    Nigel
Sign In or Register to comment.