TSC Meeting Notes 2023-10-05

Owned by Christina Tempelaar-Lietz
Oct 05, 2023

Attendance:

  • Cary Phillips
  • Christina Tempelaar-Lietz
  • John Mertic
  • Joseph Goldstone
  • Kimball Thurston
  • Larry Gritz
  • Nick Porcino
  • Peter Hillman
  • Rod Bogart

Guests:

  • Lucas Miller, Sony
  • Li Ji, ILM
  • Andre Mazzone, ILM
  • An Nguyen, ILM
  • Megha Shastry, Disney
  • Davide Selmo, ILM
  • Matt Graham, Weta Digital

Discussion:

Background of OpenEXR project

  • Slide presentation by Cary
  • TSC intros:
    • Rod B, Epic Games/former-ILM - gave some historical background - initial idea was can we get extended range (which is what EXR stands for)
    • Peter, Weta- support for deep image data needed by Weta 
    • Joseph, ARRI/former-ILM - named EXR among many other contributions.
    • Nick, Pixar/former-Apple and ILM - involved more than 20 years ago, responsible for some additions to Imath
    • Larry, Sony - original author of OpenImageIO, one of biggest consumers of OpenEXR, and co-chair of dev days and author of OSL
    • Kimball, Weta - complete rewrite of library via EXRCore (C implementation), CMake setup
    • Christina, ILM/former-Epic - continuous integration and SonarCloud setup
    • Cary, ILM - chair, takes care of many tasks
  • Guest devs intros:
    • Andre M
      • engineering lead lighting rendering and look dev, use EXR every day, own deep id implementation
      • dev days interest: production AOVs and metadata, trying out new scene hierarchy, make example image
      • Larry mentioned image doesn't matter just having real-world image for test bed for evaluating compressions methods would help, rest cases such as representative deep images, need good test data, 
    • Lucas M
      • one of Alembic authors, wanted to purge dependency on boost, experience with PyBind11,
      • dev days interest: wants to get PyBind11 python bindings framework started
    • Li Ji
      • interested in cleaning up python bindings as well
    • An N
      • on Andre's team, started looking into example file that annotates byte-by-byte - looking to clean it up
    • Megha
      • procedural tools for grooming and look dev
      • dev days interest: look into how to get started in contributing, looking for something easy, adding and improving tests
    • Davide S
      • Image capture team, maintain 2d libraries
      • dev days interest: interested in the initiative, adding and improving tests, open to other projects
      • former Foundry worked on Katana
    • Matt G
      • spans whole pipeline from real time rendering to output images, use OpenEXR throughout, many tools build against it, great that its in the VFX standard
      • dev days interest: general, looking at how to contribute
  • Bigger projects on wishlist:
    • Investigate new compression schemes - to note Kimball swapped out zlib for libdeflate
      • Rod: also an issue how to deal with lossy compression
    • Performance metric suite - something easier to validate and evaluate changes
    • Support for bfloat16
    • Fast way of reading just the header information
    • Generate something GPU agnostic that works with DirectStorage
    • Rod: more sample images
      • not so much what's in them but how they are laid out - e.g. Epic uses multi mipmap tiled images for skies
      • Nick: images with different scanline order (everything we currently have is "increasing Y", no "decreasing Y")
    • Static libraries fail on FreeBSD, not a problem on other platforms
    • Website fixes
    • Verifying example code is still functional (possible project for Megha, Cary mentioned)
    • Fixed array and buffer protocol in Imath - converting to PyBind11 may be an enormous headache