ASWF USD Working Group | 2024-11-20

General USD at ASWF
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Hi everyone,

The USD working group is meeting tomorrow afternoon, Wednesday, November 20th at 1pm Pacific (PT). Everyone is welcome to join.

The agenda for this meeting is:

Meeting link (LFX registration is optional):

https://zoom-lfx.platform.linuxfoundation.org/meeting/96955375634?password=f8dd722d-2a2b-41bb-9fc7-f09aacaf11b2

Meeting notes can be found here:

Please feel free to reach out to us, comment below or come to the meeting with new items, question, and ideas - all are welcome!

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2024-11-20 was my first (online) participation in this working group - just out of curiosity - because IFC 5 (next/ future edition of ISO 16739-1 “Industry Foundation Classes (IFC) for data sharing in the construction and facility management industries”) will be based on OpenUSD (as far as I understand).

Unfortunately I wasn’t able to attend the AOUSD Summit 2024 you mentioned in your talks. And I am still a little bit confused: On one hand the M&E domain was mentioned. (What does this abbreviation stand for in your understanding? I only know it as abbreviation for Media & Entertainment - at least that’s what Autodesk seems to mean with it:)
https://www.autodesk.com/design-make/me
And on the other hand IFC data schemas were mentioned (e. g. HVACs, plumbing).

While I hope you will sooner or later fill me in on your intended meaning of M&E, maybe I could shed a little bit of light on what seems to be the original question: Why the buzz about IFC 5 and OpenUSD? (Disclaimer: I am neither expert nor practitioner - I’ve been just following the development of Building Information Modeling/ IFC over the last years in the context of some potential business ideas of mine. So, the following is to my best knowledge/ understanding but without any warrenty)

All previous versions of IFC (up to the current version 4.3) have been based on the EXPRESS Language (as defined in ISO 10303-11) with the “recommended file format to exchange IFC 2x3, IFC 4 and IFC 4.3 data is the STEP Physical File Format (SPFF) as .ifc.” (As defined in ISO 10303-21)
https://www.buildingsmart.org/standards/bsi-standards/industry-foundation-classes/
https://technical.buildingsmart.org/standards/ifc/ifc-formats/

As Léon van Berlo, Technical Director of buildingSMART International (the organization developing and maintaining IFC and other related standards), states in his recent talk “30 years of IFC”: “So, we have about 300 exceptions now in IFC 4.3 and that is 300 risks of implementing it in a non-reliable way.” (29:00 - 42:28 with his email-address for further questions shown at the end of his talk 42:22 - 42: 28; core part about IFC 5: 35:10 - 40:11).

This might very well be due to the limitations of the EXPRESS language and/ or the STEP Physical file format (besides the latter being monolithic and not modular)

He also states: “So, I’m not sure if some of you have already noticed but first examples are already online. We have a “Hello Wall” which is one wall and a space, two windows – it’s actually one window type that is placed two times – and we have an alignment curve with signals that are following the curve on different stations. So, these two examples are really like almost everything that we need in the core is in there: Reuse of the geometry in the different types, positioning placement. Everything is in there, even references to the bSDD. You can also already see the direction we want to go with IDS there as well. So, highly recommend if you’re motivated to learn about this, I highly recommend to look at it. It’s on our GitHub page. It has little documentation. We want to stimulate you to actually figure it out.”

If you want even more specifics, you could watch the slides and videos relating to IFC 5 (part 1 - 4) of the latest “General Assembly of Implementers” (August 2024 - Trimble - Westminster, CO, USA), probably especially “David de Koning - IFC 5 part 3: existing solutions (USD)”

The main reason for my probably rather lengthy intro (now, that IFC will be based on OpenUSD and a hopefully enhanced understanding why):
Could there be reasons for AOUSD member companies to follow the Architecture, Engineering, Construction, and Operations (AECO) Interest Group more closely, maybe even use the Liaison Agreement with buildingSMART International to form something like a complementary IFC 5 Interest Group at buildingSMART International and/ or their General Assembly of Implementers?

(Maybe even attract new member companies?, E. g. Wayfair seems to be quite innovative, too and is a Khronos 3D Commerce member company like IKEA or LOWE’S)

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Welcome to the forum @ralf.vogelsang ! I’ve updated your settings so you can edit your post to include the full details.

Yes, M&E stands for Media & Entertainment. ASWF is mainly focused on M&E and this is now complemented with the AOUSD AECO IG to better cover this area. (Adding @Angel.velez here for general information about it). There’s a free membership tier that enables you to easily join this IG so you can share your feedback with the group directly, ask questions and contribute to the effort (join.aousd.org).

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Thank you for the detailed notes Ralf, that answers many of my questions.

Welcome to the forum, I look forward to further conversation around this topic!