BlenderBIM and Revit: not importing, also IFCMaterial is not connected to the object.

edited July 2021 in General

Anyone have an idea whey this IFC file doesn't open in Revit? It links, but doesn't 'open'.
...
Also, although an IFCmaterial is created in the BlenderBIM file, when this IFC is imported into BlenderBIM, it doesn't create the IFCmaterial. There seems to be a disconnect there.

Comments

  • Potentially because it is an IFC 4 which uses tessellations? I forget if opening supports tessellations or not. Does it work in other viewers?

    The file looks fine from an IFC point of view. I see you have created a material, but not linked the material to the object. Perhaps this is a UX problem more than a real error.

    Blender materials can either represent an IFC material, or an IFC style, and if you ask it to, both.

    If a Blender material represents an IFC material, and that Blender material is assigned to a Blender object, it does not mean that the IFC material is assigned to the IFC object. This is a source of confusion where users might think they have a material assigned when they actually do not. The only way to properly assign an IFC material to an IFC object is via the IFC Object Material panel in the Object properties tab. The reason for this confusing UX is because IFC materials are not as simplistic as how Blender makes it out to be.

    If a Blender material represents an IFC style, and that Blender material is assigned to a Blender object, it does mean that the IFC style is assigned to the IFC object.

    Hope that helps. Suggestions welcome on how to improve the UX.

  • The only way to properly assign an IFC material to an IFC object is via the IFC Object Material panel in the Object properties tab.

    That was it! Thanks. No problem on the UX, I understand.
    ...

    Potentially because it is an IFC 4 which uses tessellations?

    That was it as well. https://github.com/Autodesk/revit-ifc/issues/315
    Is there anyway to make an ifcextrudedareasolid from scratch? I remember we used to use blender's vertex groups, but that approach was deprecated, if I'm not mistaken.

  • I spotted an issue where the import didn't handle material definition representation with styles being merged very well. Fixed :)

  • Yeah now if you want simple IFC extruded area solids from scratch, there are two methods.

    1. Use a material profile set in your type. Then, any elements of that type (commonly columns, beams, etc) will inherit the profile and use it as an extrusion. The profile is parametric. Right now, I'm in the process of making this UX better for columns still. Beams will be next.
    2. Just model it! Then choose the right magic button in the mesh tab, and it'll turn it automatically into an extrusion. Magic! No messing around with vertex groups and pressing 200 buttons.

  • Also the ifc 'open' method shouldn't be used in Revit anymore, that's the legacy way, always use the 'link' method. If you want to work on the file in Revit, just open the created RVT file next to the linked ifc. Revit actually doesn't link the ifc, it just converts it to rvt, than links that rvt, than you can open this rvt file.

    The open method uses some old API, while the linking uses the DirectShape API.

    Some other differences of the 2 ways:
    Open:

    • Every element is a different type, so no real types, huge file size
    • All parameters imported as Type parameter
    • There is one instance parameter: IfcGUID
    • Ifc elements show up in the project browser, and they are in-place models. If you copy them they will duplicate in the project browser and in schedules as well. But you cannot create a new instance from the project browser (just like with in place models)

    Link:

    • Parameters are created as Instance parameters, you can schedule and even modify them
    • Schedules created automatically listing all parameters
    • Imported types don’t show up in the project browser, but you can copy them in a view. After copying they still won’t show up in the project browser, but they will show up correctly in schedules.
    theoryshaw
  • Unfortunately, the open method is capable of certain native object conversions that the link method is not. For example, linking always brings in rooms as generic objects, but opening can bring rooms in as rooms. So in certain cases, unfortunately, opening is a necessary evil.

    Aceinfeeeee
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