Bim Collaboration Format (bcf)

[Jarrell Campbell]

BIMCollaboration Format is a standard established by buildingSMART. BCF is an open format that facilitates model-based communication of issues between different BIM applications, without submitting the whole BIM (model) each time. The use of BCF also makes it possible to track issues.

Being a format based on open standards means that interoperability is enhanced. Project parties can collaborate coordination information and exchange models even if they use different BIM authoring software applications. They can identify areas in the models and communicate these areas; i.e., communicating about issues within Building Information Models (BIMs). The format increases collaboration between the project members, reduces risk such as information loss and makes the process even faster and more efficient.

First, BIM Collaboration Format includes information such as description, author, assignee, status, type, creation date, due date, GUID (Global Unique ID) etc. It also contains visuals, including viewpoints (IFC coordinates), snapshots, screenshots, and markups. BCF has references to the 3D model, to elements in the 3D model, to documents and to other issues. Communication is also stored such as correspondence and comments related to issues.

BCF contains documentation including changes and amendments to the issue. All of this is saved as an XML and will generate results into a BCF file, so it contains all these aspects in a very simple way so the files are not too big.

The second workflow is a BCF server that saves and manages all these issues and BCF data on a cloud server. The issue is assigned to the right member and it is not duplicated. Additionally, it is transparent so every collaborator can have access to the information.

A quick primer for those new to BCF. BCF (BIM Collaboration Format) is a specification to transfer issues about a model. It's basically a standardisation of a typical software development bugtracker fields like issue name, issue description, priority, assigned, due, etc. However, it has a few additional AEC specific things like viewpoints (i.e. camera angles of the problem), snapshots (screenshots of the problem), screen-space markups like lines and images, and construction phase, etc. Also, for whatever reason instead of calling it an issue or bug, they call it a "topic". It's the same concept though.

Anyway, previously the only FOSS BCF lib I was aware of (at least for Python - there is an old C# one part of BCFier) is bcfplugin, built as a GSoC project for FreeCAD's BCF feature. There are, however, some issues.

It's 10 times smaller (only 800 something lines of code), less dependencies, decoupled from GUI, decoupled from XML, and a bit more feature complete. Still a work in progress though - I'm currently rebuilding the BlenderBIM Add-on's BCF capabilities to use this library instead.

Ping @yorik - it may be worth rebuilding FreeCAD's implementation to use this one too. Firstly because I suppose FreeCAD must've been missing some features since bcfplugin was definitely missing some features, and secondly so that FreeCAD can easily support BCF-API in the future.

@Moult great if we can get BCF-API support from a common source for FreeCAD & BlenderBIM. Such an obvious way to do collaboration. You may find this paper interesting: -bcf-as-a-mediator-for-task-management-in-building-design

There isn't a stable release of ifcopenshell 0.6 that you could target. For the time being, the python library and Blenderbim require a development version of ifcopenshell, so it makes sense for a user to update them all at the same time (though I notice the library bundled in the windows add-on is a bit behind).

Yes - FreeCAD and the BlenderBIM Add-on share things wherever possible - the previous bcfplugin was shared, but I've decided that there are too many downsides to keep on using it. Hence why I'm listing the issues and recommending FreeCAD to migrate too.

The reason the BlenderBIM Add-on is part of IfcOpenShell is actually not due to the dependency - the builds use the bot binaries and the folder structure is independent. It is no different to FreeCAD. Actually the reason is more historic. I started hacking on Blender + IFC support in 2019. That's when the name "BlenderBIM" appeared. Thomas, however, built IFC import support into Blender 10 years ago. The original name was "IfcBlender", just like there is an "IfcMax" in IfcOpenShell. When I joined, I was simply hoping to contribute to add IFC export support (that's why the source folder is called src/ifcblenderexport). Thomas is the true inventor of the BlenderBIM Add-on. As I built more export features, I had to add the features to the import too, to slowly get import and export to integrate. One thing led to another and it grew into the BlenderBIM Add-on, but the original offering was always part of IfcOpenShell.

@Moult so how do you as a developer decide when to build on an existing project and when to start a new one. I'm thinking of which supports Revit, Navisworks, XbimXplorer. My thinking is that with support for more software there must in theory also be more support for growing the project and greater feature development. Ahhh - just realized that c# development off windows is a pain. I'd forgotten about that. But are there other considerations?

So I've shared this on twitter and added an RFE to pyRevit

Thanks for the history information....

I assume it is similar to bimtester... It started small... than grow...

Off topic Just realized if it grows even more it could be used for testing all BIM data even if it is not from ifc. Than it would not be related to ifcopenshell.

@duncan in general I try to reuse whenever possible. I reused and did a lot of work on bcfplugin a lot before I decided it wasn't worth it, for the reasons listed at the beginning of this thread. And yes, bcfier is C#.

@bernd correct - that is why bimtester is called bimtester and not ifctester :D It can test anything, connect to anything ... for example, it should connect to bcf! Especially with all these new workflow-based standards like ISO19650 and upcoming OpenCDE APIs that can complement it it should connect to those too... oh and the BSDD API...

Just over a decade ago, project users who were working with BIM -data and models were burdened with many manual processes. One of the biggest pain points occurred when professionals compared different versions of the BIM model to identify the kind of changes required during the design process. This required BIM users to deal with large data sets as the entire model had to be exchanged as a bulk of data. The process was manual, unclear, and required significant effort and time.

But in 2014, buildingSMART helped drive a more collaborative way of working with rich BIM model data. The organization developed an open standard to enable easy and fast information exchange between different software solutions, like the Industry Foundation Classes (IFCs) model sharing standard, but for issues.

Now, picture this: you are working on an important international project, and you want to analyze issues raised to understand what changes need to be made to the BIM model and so do other architects and design teams working on the same model and project.

You are working with various design teams working in different software applications. You need to export issue information including comments, image attachments, and more BIM Collaboration Format (BCF) standard fields, as well as share it with other architects. If they are working in a different design software solution, the collaboration process becomes complex as each team needs to analyze those changes in solutions that do not speak the same language. This results in a long and non-collaborative workflow and the inability to effectively communicate required changes.

Apart from that, there are certain countries where BCF is required on most of the projects for collaborative design and operation information exchange, such as Norway. For countries like Denmark and Sweden, BCF is the desired format for exchanging coordination issues data.

With BCF export release in Autodesk Construction Cloud and BIM 360, users can now export issues to BCF file from the model viewer, get the file emailed back to them, and continue their workflow by importing the file into other BCF compatible software. Along the process, Autodesk Construction Cloud or BIM 360 act as the main hub for your project issues, and for all project issues once we launch BCF import capabilities.

BCF format allows your teams to communicate the information about the objects in your model and improves IFC-based processes. It helps your teams identify and exchange model-based information through issue exports between BIM software tools, streamlining workflows and minimizing the number of steps that need to be taken throughout the design process.

Once issues are exported, they may be pushed into another BIM software used by project stakeholders. Once all the changes are made to the model, the model can be uploaded back to Autodesk Construction Cloud or BIM 360 for all members of the project to continue working in one common data environment supported by extensive project and account level analytics and insights to help project teams further mitigate and prevent risks.

In order to support efforts focused on enabling collaborative environment for project teams, Autodesk has become a strategic member of the buildingSMART International Association. buildingSMART has adopted the Open BIM Collaboration Format (BCF) as a buildingSMART standard back in 2014 and continues exploring the industry to support the continuous development of processes and workflows.

We recognize the importance of enabling your project and design teams to have all the capabilities supporting collaborative model information exchange, which is why our R&D team continues to develop further capabilities, the BCF import being one of them. Stay tuned and subscribe to our blog to learn about upcoming releases!

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