22 June 2020

Notes for meeting of Monday, 22 June 2020. 18:00 CEST / UTC 16:00 on #blender-coders on blender.chat.


  • Blender source code was upgraded to C++17, its features can now be used throughout the code. The minimum required compiler versions increased.
  • Grants/contracts ending:
    • William Reynish starts a new job in August, so he won’t have much time moving forward to oversee the UI module.
    • Nathan Letwory will continue his work (release management, onboarding, …) for July and August. But the position will be restructured afterwards.

Modules Organization


  • The 2.83.1 release is planned for this week coordinated by Jeroen Bakker.
  • 2.83.2 can happen the following week (if there are critical fixes to be ported).


  • The bcon2 starts this week on June 24.
  • Sybren Stüvel posted the upcoming changes for Alembic aimed at 2.90. Feedback is welcome.
  • There are at the moment 822 hundred issues that concern the developers (among bugs and untriaged reports).
  • It may be good to do another “Bug Fix Sprint”. Dalai Felinto suggests (if we do it), to do it between bcon2 and bcon3 (instead of bcon3 and bcon4 like last time).

Google Summer of Code

  • First evaluation period June 29 - July 3.

The final one-line project introductions:

  • Matt Overby (mattoverby): I am implementing a volumetric soft body solver in Blender for hyperelastic materials and self collision.
  • Sam Kottler (samkottler): I am continuing the Many Light Sampling project from 2018 which implements a paper that will allow faster/less noisy renders for scenes with many lights.
  • Sriharsha Kotcharlakot (Sriharsha): I am working on adding viewport display options to visualise liquid simulation grids and improving existing fluid display options in Workbench.

New Features and Changes

Blender 2.90


Initial object transform and deformation motion blur support. Support for hair motion blur and improved quality is being worked on. (details) (Clément Foucault)


  • Embree is now used for ray tracing on the CPU. This significantly improves performance in scenes with motion blur. Other scenes with high geometric complexity also benefit on average, depending on the scene contents. (stats) (Stefan Werner, Brecht Van Lommel)

  • Hair curves are rendered differently due to the switch to Embree. GPU rendering was made to match Embree. There are now two shapes to choose from: Rounded Ribbon and 3D Curve. (details) (Brecht Van Lommel)

  • New, more accurate sky texture with sun light component. (details) (Marco, Lukas Stockner)

Grease Pencil

Operator to bake static and animated meshes to grease pencil strokes. (Antonio Vazquez)

User Interface

  • Constraints stack and layout was updated to work the same as modifier, with drag & drop reorder and quick collapse and expand. Modifier header layout was also improved. (Hans Goudey)
  • Ctrl+click on an open panel now expands all subpanels. (Hans Goudey)
  • Outliner: unified delete hierarchy operator for collections and objects. (Nathan Craddock)
  • Outliner: improve performance when expand/collapsing and resizing. (Julian Eisel)


  • Overrides: various performance improvements. (Bastien Montagne)
  • Cloth: support forces acting parallel to cloth. (Alexander Gavrilov)
  • Alembic (Sybren A. Stüvel)
    • Use mesh name as part of exported object name.
    • Always export object transforms as inheriting, for wider compatibility (with both Blender and USD Alembic plugin).
  • Mesh
    • Bevel: add new Absolute mode for interpreting amount value. (Howard Trickey)
    • Extrude, Dissolve and Intersect renamed to Extrude Manifold. (Germano Cavalcante)
  • Transform (Germano Cavalcante)
    • Vertex slide now supports all snapping types, instead of only increment.
    • Snap to the intersection between constraint and geometry (details)
  • Python API: new bpy.data.libraries.write() parameter to control path remapping. (Campbell Barton)
  • Animation Player: support DJV 2. (Campbell Barton)

Weekly Reports