January 18, 2021

Host: Michael Dolan

Attendees:

• [X] Mark Boorer (TSC) - Industrial Light & Magic

• [ ] Mei Chu (TSC) - Sony Pictures Imageworks

• [X] Sean Cooper (TSC ACES TAC Rep) - ARRI

• [X] Michael Dolan (TSC Chair) - Epic Games

• [X] Patrick Hodoul (TSC) - Autodesk

• [ ] John Mertic - Academy Software Foundation / Linux Foundation

• [X] Carol Payne (TSC) - Netflix

• [X] Mark Titchener (TSC) - Foundry

• [X] Carl Rand (TSC) - Weta Digital

• [X] Doug Walker (TSC Chief Architect) - Autodesk

• [X] Kevin Wheatley (TSC) - Framestore

• [X] Bernard Lefebvre - Autodesk

Apologies:

• Mei Chu

OCIO TSC Meeting Notes

• Doug to summarize in-progress work:

  • Doug: Number of PRs landing this week. Bug fixes in Python bindings, etc. No new features. Small but appreciate quick turn around.

• Any volunteers to help get the OpenFX plug-ins compiling (PR #1232)?

  • Doug: Contributor needs help with compilation and loading in OFX compliant app. Doesn't need help writing plugins, just initial step of getting it built.

  • Michael: Currently is swapping code into a Resolve plugin example I believe.

  • Carol: Is there more we can do to help people get up and running with OCIO? Many new developers are struggling to get up and running. Not sure what the issue is.

  • Doug: Valid point. Heard similar feedback from ACES community too. Not all those trying to build OCIO are necessarily developers.

  • Sean: Might be lack of familiarity with C++ build env.

  • Carol: Could link to some CMake help for getting started, etc.

  • Sean: After release, when we get into other package envs, those complaints will go away.

  • Michael: I brought this up in the last CI working group. Pushed for making one of the goals this year to work on standardized package manager support across ASWF projects.

  • Mark T: He had example plugins building. I talked to him about some of that. Is able to build examples now, but not able to build his plugin.

  • Michael: We can do zoom to help support if needed.

• VFX Reference Platform 2.0.x -> 2.x:

  • Michael: I reached out to the platform working group and the TAC about the change and got good feedback. OpenVDB has always had a variable minor version, but has to be handled carefully. Stance from VFX ref platform is that a CY version range must be ABI compatible.

  • Doug: Challenge is we may want to do 2.x release that breaks ABI compatibility. Lots of things could break it.

  • Michael: Can do minor version ranges in platform, if we could commit to certain minor versions being ABI compatible.

  • Doug: Anyone rememberer when tetrahedral interpolation was added to OCIO v1? Did that break ABI compatibility?

  • Kevin: It didn't quite. Was able to put binary from Nuke into Mari and it worked.

  • Patrick: Can add enum, but add at end.

  • Doug: Risk is committing to all 2.x not breaking ABI.

  • Patrick: Need to say that for next 9 months, no change will break ABI compatibility. Since v2 is first being used, challenge to say that.

  • Carol: Have not done enough testing to be confident.

  • Michael: Semver doesn't explicitly say ABI compatibility, but sort of implies it in minor version changes being backwards compatible. That would impact the decision too.

  • Patrick: We will have to change API.

  • Carol: Might be 6 months before we see v2 release with Nuke.

  • Mark T: Yes, taking longer than we hoped. also delay getting into production once it's in DCCs.

  • Michael: Suggest we back out changes if we're not confident in adhering to the rule.

  • Doug: Will need to be 2.0.1 as bug fix, and then eventually 2.1.

  • Carol: Can push bigger changes to CY2022.

  • Mark B: Don't forsee needing to use these new features at facility scale in 2021. Not a huge deal if VFX ref misses some of those minor features.

  • Michael: We're currently missing builtin transforms needed for the ACES config. Would we need to resort to LUTs to get that out?

  • Doug: Can do like was pasted in Slack a while back, building the output transforms in the config.

  • Michael: Any performance cost? Or since builtin transform just builds ops directly, is it about the same?

  • Doug: Shouldn't be. Have not tested yet.

  • Michael: Complicates config build script a bit. ACES 1.3 can wait, but we will need output transforms.

  • Kevin: How many releases could we have this year? How many versions on active support? Committing to support VFX ref platform. Minor versions could be more to support. Tradeoff of not locking ref platform down.

  • Mark B: Could add broken endpoints for features we're planning to add. Then API won't change.

  • Michael: Good idea. I have seen other libraries do that. Let's continue this discussion in the config wg meeting tomorrow. I will followup with platform working group after that.

• Release plan discussion for 2.0.0:

  • Doug: Would like to do 2.0.0 release next week, Monday or Tuesday. Minor PRs in this week to merge quickly.

• Issues, Built-in Transform, Documentation, or other “must haves” for 2.0.0:

  • Doug: If there are things people feel are must haves, want to get them on table. Bernard working on issues. Not currently working on reported OpenEXR 2.5 CMake issue.

  • TODO: Michael will roll back OIIO find module to resolve that issue for now.

• Ociocheck behavior for missing roles:

  • Doug: ociocheck looks for known set of roles. If they are missing it prints error message. Added new roles to OCIO v2, so was going to add them to OCIO check, but they aren't mandatory. some of the roles it is currently complaining about don't seem mandatory. Propose changing message to warning instead of error.

  • Kevin: Difference in behavior with new roles. They are required in certain circumstances. Without matte_paint role config will work. Would like a strict check that validates as an error. Agree on some other roles being warnings though.

  • Sean: Core roles could be hard coded in DCCs and know that those exist. More for DCC/API compatibility. With newer v2.0 features, can question whether they are necessary.

• Should inactive color spaces be included by parseColorSpaceFromString?

  • Doug: Inactive spaces won't be in menus. Should we parse inactive color spaces from strings?

  • Kevin: I think so. Useful for loading historical color spaces. Like to be able to load file on disk.

  • Mark, Sean: Agree. Good to load them still if it's defined.

• Scope of image IO support for app refactor (to remove OpenImageIO dependency):

  • Michael: I've been building simple image interface to load EXRs for apps. OpenEXR is a broad interface though, with many types of files. Should we support them all? Or limit it since the apps only operate on RGBA?

  • Mark B: Think we can keep the OIIO dependency. If needed can change how they are built, with apps in another repo, or a separate CMake build.

  • Kevin: Package managers would prefer library and tools separate.

  • Mark B: That's what debian and brew do.

  • Patrick: Agree not a huge problem, but falls in problem category. Two types of commandline tools. Helpers and apps like ociodisplay, which are useful for development. Moving tools for external users outside could be good. But ocioperf less convinced. ocioperf would be ok only having OpenEXR format. Tool we really need OIIO for is ociodisplay.

  • Group agrees to continue discussion next week and in GH issue. Leaning toward keeping OIIO dependency and implementing one of Mark's suggestions.

• ASWF 2020 CCLA 2.1 transition:

  • Sean: What would the timeline by for this change? 6 months?

  • Michael: I talked to John and it sounds like we can get the new CCLA signed before we switch and then switch it over once we know there will be no disruption to contributions. Will follow up more on this next week.

• Items for next TSC meeting agenda:

  • Removing apps from repo or main build.

  • ASWF 2020 CCLA 2.1 transition plan.