OCCT 6.8.0 beta version is ready for testing!


Dear All,

I am pleased to inform you that OCCT 6.8.0 is ready for beta testing.

We invite you to test this beta version in your applications. If you have reported some issues in bug tracker, please check those with Verified status -- we assume they are fixed, and will appreciate to see your comments in the notes of the issue. If you detect a regression, please report it as soon as possible.

Use the commit tagged "V6_8_0_beta" in the Git repository for this testing. If you do not have direct access to the repository, you may download the archive of sources from GitWeb (just click on the "snapshot" link).

The new version of WOK (6.8.0.beta) is available on the Resources page (Windows and Linux only).

This version improves generation of header files and supports binding to VTK (required for new VIS component); you can keep using previous version (6.7.1) if you do not plan to use VIS.

The users who are not ready to build from bare sources with WOK can use the complete source archive or installer (on Windows).

For details on the content of the 6.8.0 release and porting guidelines, see draft Release Notes.

We are going to publish additional information on new features in this release as separate messages on this forum, please follow and comment. The final release of 6.8.0 should come by the end of October, but the date will also depend on the feedback we obtain from beta testing.

Your feedback is very welcome!

Roman Lygin's picture

Hi Andrey,

Congratulations on the 6.8.0 beta!
Let me share first feedback:
- All the fixes (6) pushed earlier have been integrated into this release. I have verified each of them and put notes into the trackers. Good, thank you to your team for the fast turn-around.
- One very recent regression has been detected (#25374). The fix is highly expected in 6.8.0 production to avoid patching OCC on our own.
- As reported earlier, #25010 had a severe side effect for us at CAD Exchanger, so we won't be able to migrate GUI to 6.8.0 but that's not a showstopper for us, we'll keep GUI at 6.7.x.
- Fortunately the issue reported a couple of weeks ago (enforced re-computation of triangulation) went away, and the behavior is now consistent with 6.7.1.
- removal of BRepMesh_PDiscretRoot type (typedef to BRepMesh_PDiscretRoot*) broke source compatibility and required some manual updates.
- I did not check fancy features and BRepMesh improvements.

Hope this will be helpful.
Thanks again.

Andrey BETENEV's picture

Hello Roman,

Thank you for your comments!

For the issues you mentioned:

  • #25374 is fixed, hope it will be tested successfully and integrated this week
  • #25010 seem to have no adverse effect at our current applications, so we are not going to dig into the problem your reported immediately. However we will take this into account when making further improvements in this area.


Kirill Gavrilov's picture

Hi Roman,

As reported earlier, #25010 had a severe side effect

I consider registering dedicated issue for this problem, otherwise it may be forgotten.

Roman Lygin's picture

Hi Kirill,

Thank you for your planning to register it separately. Certainly please go ahead.

The root-cause of the side effect is apparently in XCAFPrs_AISObject::SetColors() which creates explicit hard-coded aspects. As far as I understand the correct code should not enforce that and rather allow the XCAFPrs_AISObject to rely on a common approach - if there is no explicit aspect in the drawer, reuse the aspect from the linked drawer (one from AIS_InteractiveContext).

Thank you,

Jayden Shui's picture

I am trying to compile it with visual studio 2013 on win64 platform. Two projects failed because the third-party VTK library is missing. I got the same problem with my compiled VTK libdary. Maybe my compliation of VTK is not right. I appreciate it if the VTK library is provided.

Andrey BETENEV's picture

Hello Jayden,

If you are using MS VS projects generated by WOK (command 'wgenproj'), you should be able to tune paths to VTK by editing the custom.bat file.

CMake build procedures in 6.8.0.beta suffer from the problems you described: detection of VTK libs is broken, see issue #25244. This should be fixed in final release.

We are going to provide archives with binaries of VTK built by different compilers on 3rd-party products page soon.


Jayden Shui's picture

May I suggest to provide an installer on the latest stable visual c++ compiler and x64 platform? I think many people use this platform.

Andrey BETENEV's picture


The idea may sound reasonable, however OCCT users work in quite different environments and we cannot know which version of Visual Studio is used by majority of them. Another point is that each user has its own configuration of third-party projects (FreeType, FreeImage, Gl2Ps, TBB etc.) to use with OCCT. For these reasons we do not consider binary distribution of OCCT as appropriate for immediate use in projects; it is rather a demo package allowing you to run and test / evaluate OCCT easily without spending time for building it. If you use OCCT in some project, we strongly recommend you to rebuild it from sources in your specific environment.

We currently use Visual Studio 2010 as in our experience it is the most reliable version, and it produces faster code.

Using x64 platform instead of win32 is a good point, we shall consider it for 6.8.0 release.

Thank you for your suggestion!