TSC Meeting Notes 2023-10-05

Owned by Christina Tempelaar-Lietz
Last updated: Oct 05, 2023
2 min read

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