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Slack Channel

Zoom meeting

USD on the Web prototype can be tested here.

Wednesday, June 15th 2022 (11:00AM PT/2:00PM ET/9:00PM GMT) Wednesday, July 13th 2022 (11:00AM PT/2:00PM ET/9:00PM GMT)

Note: Proposed agenda rescheduled to next meeting due to audience particularly interested in USDz validation unable to attend.

  • Anything interesting to show?
  • Proposed agenda:
    • From previous conversations:
      • USDz support can require significant effort for validating assets, and is a manual process.
      • Proposed action item: combine efforts to create a validation tool, if issues are difficult to raise to vendors/implementers.
    • Potential questions:
      • Have the issues resolved at the source ((smile))
      • Enhance existing usdchecker vs. develop a different tool?
      • Which runtime versions should be supported/specified?
      • etc.

Wednesday, May 18th 2022 (11:00AM PT/2:00PM ET/9:00PM GMT)

  • Follow-up on conversations from previous session about comparing glTF and USD for visualization
    • Eric Chadwick provided a description the Wayfair workflow:
      • Relying on 3ds Max and Maya to author and design content, using mostly VRay materials
      • Baking down textures and geometry to later package assets in USDz format
      • Strong overlap with parallel conversations about LoDs, texture/mesh compression also covered in main Working Group and Games sub-working group
      • Regarding interactive experiences (mobile/AR/VR/XR), fast loading time, rendering-optimized content is a must
        • Users/downstream consumers are unlikely to stand with their devices while waiting for content to load
        • Experience may be jarring if content suddenly appears in the world, or partially loads
  • Early conversation about combining efforts regarding asset compliance/validation for Apple's USDz format
    • Avoiding reinventing the wheel by sharing tools/scripts to flag potential known issues with Apple's interpretation of the format
    • Perhaps enhancing the usdchecker tool to support more options, or take inspiration from the tool and build a separate/specialized one

Wednesday, April 20th 2022 (11:00AM PT/2:00PM ET/9:00PM GMT)

  • Touch point on the principal focus of the initiative:
    • Common agreement that the focus of the project is not to compete or dethrone glTF as the transmission format for assets and content on the web.
    • glTF has specific targets, use cases and built-in optimizations specifically targeting transmission and "last-mile" delivery of assets, which is less of a concern for authoring formats such as USD.
    • It may be worth revisiting some of the existing documents published to state this more publicly, as this none-competitive aspect may otherwise not be clear to the audience outside the USD Working Group.
    • Potential future work may include publishing a "best practices" guide regarding publishing USDz assets for the Web, covering topics such as asset complexity/density, texture optimizations, known limitations, etc.
  • Alexander Schwank shared updates:
  • Potential groups worth reaching out to regarding USD "runtime" features:
    • Sketchfab
    • Shopify
  • Potential Questions for the larger USD group:
    • Does Autodesk envision any specific use cases for WebAssembly? Any gaps, limitations with the current prototype?
      • Jerran Schmidt- While data visualization is one component, I did mention briefly in the HgiWebGPU presentation that web-based USD content authoring applications are a particular use case for this. (Note: I no longer represent Autodesk on this)
    • Does Pixar see any potential openings for platforms other than X86/64-bit architectures?

Wednesday, March 23rd, 2022 (11:00AM PT/2:00PM ET/9:00PM GMT)

  • Demonstration of an early prototype of HdStorm built to WebAssembly
  • Demonstration of an early prototype of USD WebAssembly running within :  
  • Recent noteworthy USD WebAssembly updates:
  • Project proposals to bring back to the larger USD Working Group, either for standalone value or for inclusion within other projects:
    • Asynchronous HTTP(S) ArResolver

Wednesday, November 17, 2021 (2:00PM PT/5:00PM ET)

Wednesday, October 20, 2021 (2:00PM PT/5:00PM ET)

  • Low traffic
  • Pitch for a topic of next meeting about glTF & USD
  • Discussion on Materials (MaterialX, aiSurface in browser)
  • Update on Autodesk & legal dept.

Wednesday, September 22, 2021 (2:00PM PT/5:00PM ET)

  • Post discussion on <model> tag

Wednesday, August 25, 2021 (2:00PM PT/5:00PM ET)

  • Demo of assets viewing and interaction in Autodesk Forge in Chrome
    • Rendering, selection, and scene-inspection
    • A lot of work has been done on bindings
    • Custom changes to WebASM build of TBB

Wednesday, July 14, 2021 (2:00PM PT/5:00PM ET)

  • Conversion from USDZ into blender and out to GLTF is a great short term solution, but...
  • Worth doing test for conversion of animated models over time.
  • Makes a compelling case for a native Sdf plug-in for GLTF import/export.
  • Past initial mesh import, would USDSkel and GLTF bi-directional conversion be lossless?
  • Draco plugin may need to support native Draco files better, or does it matter in a separate Sdf plugin?
  • KTX as native Hio plugin would likely be mandatory, does Hio support unpacking direct to GPU texture via Hgi? (Brian from AMD hints at a yes)
  • Is MaterialX and its advances (especially in tackling WebASM) going to be the way forward for all shading interchange in USD.
  • OCIO and color accuracy again came up as important, but too large a topic compared to getting a better bare-bones implementation anyone can use.
  • Video Conference Link

Wednesday, June 2, 2021 (3:00PM PT/6:00PM ET)

  • Autodesk showed USD import into Forge.  Translates to Forge-native geometry.
  • Autodesk also working on a WebGPU Hydra delegate that does PBR shading.
  • A lot of overlap between the delegate above and Filament (i.e. SPIR-V tools running in browser)
  • TBB remains an issue that everyone is keen to solve.
  • Philippe Sawicki working on an MVP list for JS-bindings.
  • Dhruv Govil is interested in what can be leveraged from ASWF initiative to auto-gen Rust bindings.

Wednesday, May 5, 2021 (3:00PM PT/6:00PM ET)

JavaScript bindings, need a real strategy on how to tackle them.

Static Initialization macros don't work well in WebASM, but being explicit about what is used for dead stripping to occur might be better for download times.

See what changes have landed in /dev that may help reduce reliance on WebAsm-TBB and its CORS issues.

Github issue for PRs

Wednesday, April 7, 2021

Working example of WebASM build of USD with a Hydra delegate for Filament

Ideally GitHub Pages version at would be a live demo, but

Wednesday, March 10, 2021

  • Roman Zulak
  • Philippe Sawicki 
  • Alexander Schwank
  • Dhruv Govil
  • Alex Gerveshi
  • Nick Porcino
  • JT Nelson

Goal is to have USD WebAsm branch and a WebAsm build of Filament Hydra Delegate by next meeting (April 7).

  • Gain a better understanding of performance and limitations loading arbitrary assets and materials.
  • Let a larger audience see the size of changes needed to support the platform.
  • If the changes are too large for Pixar to mainline, what options are there?
  • Provide a use case for Filament that could help push HdFilament code into Google's repo.
  • Initially may be a private repo/branch not totally accessible to the world.

JavaScript bindings to USD.

  • Roman has started porting a ui-handle implementation to WebGL that would be simplified with re-use of Gf/math library.
  • What is the cost (in terms of source code) for additional bindings.

Python support via browser (à la Pyodide)?

  • Is there any gain in having existing Python scripts run in a browser?
  • May be too expensive of a runtime environment.

Plugins and external dependencies for a WebASM build:

  • http(s) ArResolver would be very useful once everything starts working.
  • OpenSubdiv is probably a good candidate for a next-step.
  • Is OpenVDB support in WebASM via NanoVDB a possibility (or useful)?
  • Qt WebASM is interesting, but a little too unstable right now.
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