buildingSMART Forums

Presenting Blender as a new IFC authoring tool

Of course, you can choose fully how much detail you want to go to. If you want to model at a lower geometry fidelity, you can choose to do so.

I have two projects currently testing this, one with ~750 elements (not counting repetitive instances) which is a relatively small building, and the other with 31,000 individual elements. This is similar to what the film industry deals with and it most certainly is manageable. The process shown in the video is manual, but there are bulk assign/editing tools available. This is certainly being tested on big projects, because we really do work on big projects :slight_smile:

Update time: apart from the COBie developments which are already covered in another thread, BlenderBIM now has an interface for people to use (including friendly drop downs and filters for classifications) which allow people to do bulk classifications and assignments of types.

It also has a QA module which allow for QA, which is really exciting! Because very often we get IFC models which are very badly misclassified.


The QA module includes a feature to allow applying a temporary colourscheme to the model based of a property. For now, the interface allows you to colour it by IfcClass, but you could theoretically colour by anything (fire ratings, acoustic ratings, any property …). Here is an example, showing walls, doors, columns, slabs, and some floating building element proxies:

You can bulk approve or reject classifications and keep track of what elements you’ve audited for various properties. Any IFC property auditing will get tracked in plaintext format in Gherkin syntax, so it reads like English:

Even though the sentences read like English, they function like unit tests in software, so they are run automatically on model publish to a CDE. If any regressions are made in the BIM model, we can get notified instantly. Standard reporting like no. of issues, changes over time are all there because it publishes to JUnit XML, so pretty much anything can read it including any CI system like Jenkins. Here’s an example of the tests being run on the model - red ones are QA failures.

We now have workflows that allow us to rapidly audit and continuously monitor the OpenBIM quality of projects.


I think it’s the time for:

If/Then clauses

And in the near future for AI-based (Deep Learning) classifications

Given/Then in Gherkin syntax is equivalent to If/Then.

Classifications based on AI is possible with computer vision and a training set of things like doors and columns and walls. Perhaps we can build AI-assisted classification, yes.

For your convenience, @gester, I have attached some screenshots showing the type of modeling that you are looking for. These tools are part of Blender’s Archipack, created by Stephen Leger, who has done some amazing work, and allows for parametric architectural modeling, where walls know they have layers, windows know they have hosts, and so on.

The scene below was modeled in … well, perhaps a minute. And yes, the diagonal cladding is parametric, and creates holes for openings. The stair is, of course, also parametric. The floor boards, also, are parametric. The little kitchen cabinet is a drag-and-drop library part.

As you can see, it is very easy to plug these “parametric” shapes, as well as any custom modeled shape (or pretty much anything - generated, using visual programming like Sverchok, the Blender equivalent of Grasshopper, or anything you can imagine) into IFC data, and export into IFC. At the end of the day, it is just geometry.

See this test export I was playing with:

I think there is opportunity to create a tighter integration with Stephen’s work and some of the IFC stuff I am doing to make it even simpler for users in the future.


Update time:

  • You can now select objects by GlobalId
  • New basic UI for georeferencing data
  • Custom psets are now supported - it can also support complex data types and you can load in your own pset templates too!
  • New UI for adding in attributes, with drop down selection of possible attributes taken from the spec. Now everyone can easily add attributes!
  • New UI for adding / removing property sets (and you can set them in bulk!)
  • New quick project setup button to add site / building / storeys.
  • Bugfixes for importing, assigning classes, and roundtripping geometry with Revit (Revit seems to expect normalised direction vectors, even though the IFC spec doesn’t require this)
  • Now supports assigning surface colours directly to object representations via styled items, as well as assigning surface colours via materials - and as the user, you have the choice which way you want to do it. To my knowledge no other BIM authoring tool supports this feature!
  • New BIMTester tool is now packaged and available for Windows. It audits your BIM file to customised rules, and generates HTML reports!
  • New UI to explicitly assign how swept solids are represented, to make it easy to round trip with Revit.
  • New UI to assign externally defined materials - more on how this allows people to create incredibly detailed CG rendering workflows soon!
  • IFC import has been somewhat rewritten in preparation to start supporting the ability to import this data too, not just geometry and basic materials and ID. The importer has been merged with the exporter and packaged as a single package to make it easy to install.

The BlenderBIM website has been updated:

A new article explaining the GlobalId attribute has been added:

This is very important for consultants providing IFC files to make sure they play nice with their GlobalIds.

Little pic of the material settings:


BIM Tester picture:


The little video below shows how easy it is to add and assign native IFC data. (Sorry for the compressed laggy GIF)


is archipack available for macosx?

@gester - yes, it is. Everything in this thread is cross-platform, and that’s the beauty of free software! I’d recommend testing out the paid version, version 2.0 - it is miles ahead of the free version.

ok, you’ve got me interested…

  1. is there a mobile version (ios)?
  2. what is actually blenderbim? another add-on? is it necessary to the archipack?
  3. is there a chance to generate a construction documentation out of the model?

Hi Dion,

I see little issue: In the tree, I see IfcSlab/box but its correct form I think should be IfcSlab/FLOOR/FloorName/Tag or IfcSlab/FLOOR/Tag

About Archipack, I’ve not investigated it yet, especially v 2.0 which is paid version, but I think in the near future we have to develop it ourselves (because of some wild ideas we have)

About mobile version (cross-platform in general) in the near future, it can/will be mobile too, thanks to some technologies like WebAssembly

Also, in the near future, we can add annotation and documentation to BlenderBIM too, there are some interesting technologies/methodologies to do that even easier than before

@gester, you queries:

  1. It is technically possible. I have known people to do it, and I myself have run it on Android on my phone (yes, even rendering in real-time). However, practically Blender is a fully fledged authoring program for industry-grade workflows - for the purposes of authoring, a touchscreen input will allow you to navigate, but you will have a poor authoring experience. A better approach would be to have a dedicated viewing software for the IFC file on your mobile device, tailored towards a specific task. This goes for any authoring tool, not just Blender.
  2. BlenderBIM is an addon to Blender that allows IFC reading and writing into Blender, as well as the necessary UI to assign, audit, and manipulate BIM data within the 3D interface. It is also part of IfcOpenShell, which contains a growing suite of tools to read and write IFCs, do MVD checking, IFC QA, visualisation, COBie, IFC/SVG/OBJ/DAE/etc file conversion, 3DS Max, and more - all of which are free and open-source software. Archipack is separate to BlenderBIM, and revolves around “domain-specific modeling”, essentially parametrically generating geometry that is frequently used in the architectural domain. BlenderBIM and Archipack can be used together, or each standalone - they complement each other: BlenderBIM focusing on OpenBIM data, and Archipack focusing on geometry. At the moment, integration is loose. We will likely integrate further.
  3. At the moment, there is an experimental script that does section cuts, there are also 3D dimensioning and labeling tools, and IfcOpenShell also has some experimental SVG conversions. None are yet up to the task of construction documentation, (i.e. with annotations, dimensions, symbols, schedules, and sheets) though this is on the to-do list. It is extremely important to solve this, as currently we are again faced with proprietary software should we want to do 2D documentation.

@ReD_CoDE - There is no “correct form” for this - it is purely a convention - data for predefined types and tags are stored elsewhere, and only the IfcClass and Name is shown in the outliner tree for brevity. I will perhaps add a configuration to reorganise the tree in different ways later. That is a good idea.

Stephen, who develops Archipack, is a capable developer and it would be a good idea to collaborate.

As mentioned above, Blender itself technically can run on mobile (it’s a cool party trick!), but feels limited on a touchscreen and a slower processor. However, @ReD_CoDE you are absolutely correct that there are other technologies to view models already available. For example, I have got IFC models into the free and open-source Godot game engine (as an alternative to Unity) which can be run on any platform, including mobile, and put into an executable to distribute to clients. It is also trivial to get the IFC model onto the web, which I have also done with some optimisation and conversion using Blender. This also works with WebVR. This is all speaking from first-hand experience delivering these outputs.


Great Tool! Blender really looks grown up and fit for the job. I see Blender can handle DXF files as import and export too. What raises questions is the version of DXF implied in the button.

I certainly hope 3D is supported with the import. I could not yet get a good import going.
It would be very cool to get 3D DWG (DXF) and IFC geometry could work better !.. with Blender!..

What does DXF 0.8.6 stand for?
Are 3D solids and meshes supported?


Read: this DWG was saved back to “DXF 2000”

I have found that the DXF import/export to be not 100% reliable. But when it does work, it certainly does import 3D and 2D geometry. I am not sure what the version number stands for, and I am not too familiar with the format. I have sometimes used Rhino to re-export DXFs, as Rhino does an excellent job at file formats from my experience.

As a side note, I’d like to share with everybody a talk by Dimitar who works at HoK presenting at this year’s Blender Conference. He has done some great work with Blender and FreeCAD in the architectural domain. He talks about parametric geometry creation, concept art, and shows what Blender is capable of.


i’m almost halfway through the dimitar’s presentation from the link above. he talks about different programs hok use for the design, but there’s no mention about a program that integrates all those functionalities (sketchup, rhino, grasshopper, revit, catia and archicad), namely vectorworks.

it has the built-in siemens’ (actually it’s a british engine, but now property of siemens) parasolid 3d engine, beside catia the best one on the market. another thing from vectorworks is marionette, which is the same as grasshopper and dynamo, also based on python. another integrated functionality is the subdivisions, based on the open subdiv library by pixar, which came public some time ago. there’s nothing from 3d that you can’t do with those tools.

what i’m but curious about is the architectural parts (automated building elements) of the presentation, so let’s move on :slight_smile:


Update time!

  • Importing IFCs now have improved mesh reuse and optimisations on shape creation leading to much faster imports! Also some bugfixes thanks to @Hans_Lammerts
  • New interface to assign documents to IFC objects
  • New interface to assign classification systems (Uniclass / Omniclass) to IFC objects
  • IFC importing now also imports object attributes
  • Bugfix in BIMTester to run and re-run multiple test suites
  • IFC COBie packaged with minor bugfixes
  • Experimental gbXML export now supports creating openings, as well as some bugfixes
  • New IFC Diff tool (basically git diff for IFC files) - this allows you to take two different IFC files and it will compare them and tell you what changed. It will tell you if geometry has changed, or
    attributes, and also the previous value of the attribute and the new value of the attribute. It writes it out to a json file which can be visualised with BlenderBIM so you can overlay changed models.
  • New experimental sectioning tool to create construction documentation. You can cut sections direct from IFC files and create view hatching / line weight stylesheets with CSS which can be mass applied across objects. Objects are smart vectors, so unlike other documentation tools, 2D documentation have SVG classes applied so each object knows the IFC GlobalId, material, and IFC class.
  • New interface to create, edit, and save IFC aggregates
  • Import now supports curves, so you can import survey point geometry that might come from 12D, for example.
  • Export now supports Blender curve objects, not just mesh objects, so you can do profile extrusions along vector curves and export them
  • A whole bunch of geometry processing fixes in the underlying IfcOpenShell library by @aothms (which are quite technical but it looks like a great job! :slight_smile: )

I am very happy to announce that we are now using Blender for very basic construction documentation on real projects! It is still highly experimental and has no interface for the public to use yet, but it’s a start!

2 Likes 01-Nov-2019 08:58 12029391

Dimitar said “I wanted a software that be between strict software and parametric” for (conceptual) design

Blender in “geometry/topology,” generally in design is really powerful and also has a powerful parametric logic too

The gap is/was it’s not an engineering software for instance for BIM, but BlenderBIM can solve this gap

@Hans_Lammerts About DXF, personally don’t see any future for DXF, it’s outdated
IFC is better choice, but needs improvement, even IFC4.2 final

“I have found that the DXF import/export to be not 100% reliable.”

There are two kinds of thoughts in our beautiful remarkable BIM AEC industry. Those who believe BIM is fully 3D object orientated and those who thing BIM is all about new ways of ‘Fusion of media & technology’, often referred as ‘Bim is a process’. Anyway, i think for both ways of thinking is is CRUCIAL for the long term to enable connections being made with old 2D engineering archives and - CAD still work being done out there.

So, If you truly and fundamentally want open formats to be support this than DXF is one of the best ways to support that. Unfortunalety DWG still is not an ‘open’ format. It doesn’t mind the DXF standard are old and not being developed further. It is probably a benefit.

At the same time i wonder what 2D and 3D open standards are being used in the field of ‘GIS’. (?)
LandXML, GML but also … DXF…

Just my thoughts, $
regards hans


These days just some from Autodesk try to say DXF is good and is a “real” open format

Those who say “BIM is all about the process,” including I, say “BIM is all about Data/Information” too. And existing BIM is “weak” in Data/Information, and also Process

IFC4.2 has a lot of improvements in “Geometry/Topology” the “inherent” issue of IFC is its “flexibility”

IFC through relationships cause “Flexibility” which is good and also has its pros and cons too

About Backwards and Forwards! because this is one of the hot topics in buildingSMART too, “if we have a middleware that can convert old files to new files and vice versa” the issue related to Backwards and Forwards will solve

Question is When will this IFC 4.2 see the light in my prevered design software of choice? IFC has gained momentum in buildings but for other sectors that have a relationship with mechnanical and topography very little has changed of the years.