Meeting of OCCT enthusiasts

Hello everybody,

not sure if this is the right place for what I want to post none of the other forums seems to be better...

Some time ago Roman Lygin founded a Open CASCADE Group ( on LinkedIn.

Using that group I'd like to ask you if you were interested in attending a meeting (workshop, conference) where we could exchange our experience about OCCT, talk about current problems, OCCT-based development, hopefully get some insights of the library from the OCCT development team etc.

If you think like commenting on it please use the LinkedIn group.


Pawel's picture

Hello guys,

as the discussion on LinkedIn concerning the possible meeting was intensified and the idea itself is supported by some of the OCC staff, I would like to move the discussion to this forum to reach a wide audience and to know your opinion on the subject.

(Dear Forum Supervisor, please suggest an appropriate forum category if you think the discussion does not fit this one).

Basically the idea is to organize a meeting involving many parties using / working with OCCT such as: the OCC Company, the open source community members, the OCC customers or even representatives of the competing CAD-kernels in order to:
- exchange our experiences gained while working with OCCT,
- support the open source development of the library,
- present our work and achievements and to look for synergies among the users,
- estimate the goals for further development, cooperation etc.

As the discussion on LinkedIn got quite long I will not quote it here in order not to discourage you from reading. Just to sum up: The initial conference would very likely be organized by the OCC company and it is possible to hold such a meeting on a regular basis (yearly, for instance).

So would you be interested attending the proposed event?


jelle's picture

An important initiative, marking that OCC is evolving as an open-source project and a shifting development culture.
Good stuff, I'd be very interested to join.


Game Milky's picture

This is an important move! I personally will participate on the event!

Best Regards


Alexander Ovchinnikov's picture

Dear Colleagues!

- I dared to support Pawel’s initiative with my below comments which (I need to emphasize this point!) is my personal opinion and position and sure could not be considered in any way as the position of Open CASCADE Company (OCC) management.

- This stuff was already published on the Linkedin Open Cascade Group forum, so I am sorry in advance, if someone has read it.

- Perhaps I am pushing it a bit forward with the below details, but the devil is in the detail, as a rule. Nevertheless, I do hope, it will be much easy to make personal decisions in favor of Pawel’s idea if these details are taken into consideration too.

1. In general I would be happy to see regular conference/forums dedicated to Open CASCADE Technology (OCCT) resulted from the common efforts of OCC team and the Open Source Community (OSC). I see many perspectives of such meetings for OCCT adepts from the OSC: starting from the most critical points (roadmap, key functionalities to be revises/developed) and up to particular best practices in OCCT usage in OSC users’ projects. Therefore I see an extremely wide field for our mutual working sessions that could be very interesting for both the OSC and the OCC team.

2. Practicing mutual working sessions (both conferences and one-to one meetings) we need to have an absolutely clear understanding of the meeting content and its objectives well in advance. Moreover we must have something tangible on the table - the materials to be presented should be well prepared and audited by the OSC and OCC experts in advance. So, above the Good Will of OCC, adequate reactivity, advanced efforts and some (I anticipate quite valuable) spent working time of particular Open Source Community experts are above all. And this resource in this context is much more valuable than OCC initiative and the OCC Good Will.

3. As a pragmatic guy, I am not sure at all that we can find (at least in the nearest future) any business agents (sponsors strong enough) from the OSC with the adequate available financial resources who will be able to take in charge organization of such conferences in the full scale mode, especially in the context of adequate frequency, that is IMHO only worth considering: I guess such meetings will be nice to have at least annually.
There could be no problem probably for OCC to organize (lead and manage) such event once. But, I guess, if we plan to run such meetings on a regular basis, both OCC shareholders and OCC Customers, who are under the hard pressure and restrictions of the current crisis environment, could be finally a bit disappointed with the way OCC spends its shareholders’/customers’ money :-) . So I suggest we should not fall into too much optimistic expectations, and need to admit that OSC members should be ready at least to cover their traveling and lodging expenses on a regular basis. I am awfully sorry for such a straight forward consideration, but it would be much better to put this aspect (a restriction, in fact) on the table in advance for the common consideration.

4. IMHO the best way to start up such meetings could be OCC commitment (that I guess would be very appreciated by OSC) to undertake the responsibility for this meeting organization in the first quarter of the next year and it could be great if OCCT adepts from the OSC provide their Good Will support to OCC in sharing costs.

Pawel's picture

Hello Alexander,

to give a better overview of the discussion on Linkedin I also re-post some of my comments:

1. I fully agree with you that before organizing anything we should be clear on what are the goals and expectations from such a conference for both the OCC and OSC. The idea of a regular meetings is also very tempting and I think the decision on the annual meeting (whether they are desired or not / what could the contents be etc.) could be one of the results of the first one.

2. Here are some ideas of what the contents / objectives for the conference might be (this represents my point of view but I think might it be interesting for all participants):

a) A presentation of some real-life projects (from OCC customers but also from companies not having a business relation to OCC) would surely give the participants a nice overview of the application fields of the library.

b) OCCT as every software has its advantages but also weaknesses. Maybe it's worth inviting a speaker representing another geometry kernel (Dassault/Spatial eg.) to make a kind of comparison between multiple systems.

c) In the past the communication with the OCCT developers over the forum ( has almost always been problematic (rather low activity from the OCCT developers). I think it is really terrific the bug tracker and the git repository have been made available now but I also think that the most of the developers not being OCC customers still remember the old times and might be reluctant to use the new tools. I think the conference would be a great opportunity for the OCC company to communicate to the open source community what are their expectations on the possible cooperation between the OSC and the OCC.

d) Although the development process has become transparent for the user because of the availability of the bug tracker / git repository i still think it is very hard to make larger contribution due to the complexity of the library. I guess external developers still tend to find workarounds for emerging problems rather than solving them (which would actually be a win-win situation). I believe it would make sense to elaborate on the methods how to familiarize the people with the internals of the CAD kernel in order to allow them to efficiently fix bugs.

I'm quite sure that processing the above points would require the commitment on both sides. I believe, this is the only way we can find synergies and benefit from the proposed conference in the future.

3. For me it is fully understandable and obvious that the lodging and traveling expenses would be covered by each participant herself / himself. I also think that some kind of arrangement/conference fee (if necessary) is fully justifiable and acceptable. However, I would not support the idea of earning money by organizing the event.


Pawel's picture


there's been a continuation of the discussion here also:

(In case someone is interested)


Pawel's picture