2025-06-05 Core Module Meeting

Meetings
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Everyone is welcome on the Google Meet linked below every other Thursday, alternating between 10:00 CET and 16:00 CET.

Present:

The meeting covers the core module topics (DNA/RNA, ID management, Depsgraph, Blendfile I/O, etc.).

Links

Updates on Blender 5.0 Projects for 4.5 Release

  • 2GB BHead limit: Has been merged. Work for a few python scripts is still needed for Blender 5.0 before moving this option out of experimental (once 4.5 is branched out and cleaned up).
  • IDProperties storage split: The 5.0 PR is getting close to be ready for merge, the reduced set of changes to allow forward compatibility in Blender 4.5 should be merged in the release branch in the coming days.
  • Embedded Linked IDs: Still very WIP. Jacques and Bastien have kept working on it a bit the past two weeks, and have addressed some points in the list of TODOs. Compatibility changes required for 4.5 seem to be very limited (essentially just detecting the embedded IDs to generate nicer end-user report when removing duplicated libraries).
    • Naming: at least on the technical level: Replace ‘embedded’ by ‘archived’, to also match ‘archive libraries’, and disambiguate from ‘embedded IDs’ (root node trees, scene collections).
  • Attributes Storage Modernization: The PR has been merged. Disabling the experimental part and removing code not related to forward compatibility in 4.5 remains TODO.
  • ID Name Size Increase: The 5.0 implementation is now essentially ready, as well as the 4.5 compatibility one, which is also expected to land in the release branch in the coming days.
  • BigEndian removal: Now that 4.5 is branched out, time to create PR to actually remove it from 5.0. Reminder: Campbell suggested to keep a trace in code (as comments) about areas that are endianness-sensitive.

NOTE: We need to call for 5.0 → 4.5 compatibility testing by users as soon as possible.

NOTE: We need to communicate directly with some external projects (some linux distributions, some utils like the file command on linux…) about some of these changes:

  • The change in blendfile headers and BHead blocks.
  • The removal of big endian systems support.

Other Topics

  • id_cast PR: This is the simplest ‘replace reinterpret_cast’ version, no fancy behavior included, but adds some checks that only valid ID conversions are done. Meeting agrees with the idea.
  • Regarding the future of Core systems (DNA, RNA), in addition to points from the previous meeting, Brecht created another design task with a broader vision/general direction proposal. The module needs to find time to discuss all these ideas more in the coming weeks and months.

Next Meeting

The next meeting will be on Thursday 19th June, 10:00 CEST/Amsterdam time (your local time: 2025-06-19T08:00:00Z).

The provisional meeting agenda will be linked in the Core Meetings Overview thread before the meeting.