Separation of Concerns for Identifiers in USD by asluk · Pull Request #105 · PixarAnimationStudios/OpenUSD-proposals

asluk · 2026-03-08T04:15:18Z

Description of Proposal

Summary

Standardize a mechanism for carrying external source identifiers on USD prims alongside namespace paths. Identifiers from systems like IFC, PLM, asset management databases, and telemetry platforms should round-trip through USD without loss or reliance on ad-hoc conventions.

Problem statement

There is no standardized place in USD to store external identifiers. Pipelines work around this by encoding them into prim names, customData, or displayName -- all with significant trade-offs. The displayName migration into uiHints makes this time-sensitive.

Glossary

Source identifier -- An identifier from an external system (e.g., IFC GlobalId, PLM part number) independent of the USD namespace path.
Identity continuity -- The requirement that source identifiers survive state transitions, re-parenting, and assembly changes.

Reference Links

Extended Unicode Identifiers -- Complementary effort on prim name grammar
UI Hints in USD -- displayName migration creating urgency
Composable Bindings (Microsoft and NVIDIA, 2025) -- Digital engineering use case

Details

Two distinct problems are often conflated: (1) an unencumbered source identifier field, and (2) improved prim name ergonomics. This proposal focuses on (1) without foreclosing (2). Two candidate approaches -- extending assetInfo with stratified sub-dictionaries vs. applied schemas with typed properties -- are compared with trade-offs and eight open questions.

Risks

Uncurated proliferation, premature standardization, adoption fragmentation, and scope creep. See proposal for details.

Alternate solutions

Existing mechanisms (customData, displayName, encoding into prim names) are evaluated in the proposal and found insufficient. The two candidate approaches are the alternatives under consideration.

Out of Scope

Prim name grammar extensions, transcoding algorithms, feature-level identity continuity, and authorship traceability. Each is identified as complementary or downstream work in the proposal.

Link to Rendered Proposal

Supporting Materials

None at this time.

Contributing

I agree to and accept the Supplemental Terms.

…hints

…iers vs. source identifiers.

Captured reviewer's additional notes on UsdModel and UsdMedia as relevant illustrations-- to be addressed in a subsequent working session. Just checkpointing for now.

…discussion.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Replace manufacturing-specific framing with three industry-neutral examples of collapsing internal asset structure (manufacturing, service documentation, M&E layout). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…feedback Adds Mercedes-Benz base-number + ES1/ES2 extension codes as a concrete example of identifier schemes with internal structural rules. Clarifies the distinction between USD built-in schema validation and domain-specific validation, which applies equally to dictionaries or schemas. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Source format provenance (URDF/SDF/MJCF round-trip), ROS package identity, multi-robot fleet composition, sensor/actuator catalog identifiers, and operational telemetry binding. References the RobotecAI interoperability REP as a concrete community effort that would benefit from a standardized identifier mechanism. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Feedback from Prof. Dr. Bernd Lüdemann-Ravit, Pooja Gupta (HS Kempten), and Michael Wagner (SyncTwin) on the source identifiers proposal: - Type-vs-instance scoping suggestion with AAS globalAssetId/specificAssetIds precedent and IDTA Digital Nameplate submodel reference (Key Questions, Emerging Consensus) - Explicit identifier typing for deterministic round-tripping, filtering, and collision prevention (Single Value vs. Metadata Package) - AAS multi-identifier pattern reference (Manufacturing section) - Wagner's bidirectional AAS Digital Battery Passport ↔ OpenUSD proof-of-concept exercising both Approach A and B (Emerging Consensus, PR linked) - Updated Appendix A context items and review bullets Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Rework phrasing to reduce AI-isms and diverge from identifiers proposal voice - Break walls of text into bullets and sub-bullets throughout - Add Media & Entertainment industry use case section (multi-vendor VFX, pre-release confidentiality, cross-studio collaboration) - Reference M&E alongside other industries in intro, motivation, and design principles - Link identifiers proposal to PR PixarAnimationStudios#105 instead of relative path - Fix line widths to ~75 chars - Drop NVIDIA platform vendor label, drop Omniverse mention Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…a Gupta feedback Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…tification distinction Signals to Semantic Web stakeholders that the proposal's separation of concerns is a domain-specific application of an established knowledge representation principle, not a reinvention. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…d assumption Cites the W3C Semantic Web Primer: the set of external identifier systems is not closed, and absence of a source identifier does not imply absence of external identity. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…rong repo GitHub markdown auto-links bare #N references to the current repo, so on the asluk/USD PR page "proposal PixarAnimationStudios#105" was resolving to asluk/USD#105 (does not exist) rather than to OpenUSD-proposals where the proposal actually lives. Replaces "proposal PixarAnimationStudios#105" with "proposal 105" in prose contexts and "Proposal PixarAnimationStudios#105's" with an explicit linked form in the PR body caveat. Fully-qualified [PixarAnimationStudios/OpenUSD-proposals#105] link forms throughout the docs are unchanged because they already resolve correctly via the explicit URL. Affects: - _pr7_body.md (pushed via gh pr edit) - extras/sourceIdentifiers/COMPARISON.md - extras/sourceIdentifiers/details/field_classification_experiment.md Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

_pr7_comment_draft.md was a pre-rebuild response to Matt's review that asserted "the doc now leans toward D" (concern 5). The leaning has been retracted; updated draft rolls forward what's responsive to each concern in the current state of the docs: - Concerns 1, 2, 3, 6, 7 unchanged (already addressed) - Concern 4 (schema-distribution friction): updated to reflect the conditional resolution (currently elevated, trending lighter as the AOUSD Build IG epic lands) per Aaron's 2026-05-07 call - Concern 5 (Semantic Labels + identity dict): expanded to note the initial leaning toward D was retracted in light of the field census showing identifier packages are heterogeneously typed in every vertical surveyed; D's labels-only surface cannot carry that surface; D preserved as explored idea with provenance note - Cross-cutting summary updated with rebuilt scoring totals and the methodology comment pointer Draft remains untracked relative to PR-comment posting workflow; the file is in the repo as a working document. Also deletes the stale local copy _pr105_readme.md (proposal lives canonically in PixarAnimationStudios/OpenUSD-proposals#105). COMPARISON.md Repository Map: added inline comment in the pxr/usd/ tree clarifying that D has no module by design (reuses UsdSemanticsLabelsAPI). The "D requires no new schema library" sentence was already below the tree, but a reviewer scanning the tree itself would wonder "where's D?"; the inline comment closes that loop. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

asluk added 23 commits February 27, 2026 17:03

WIP for identifier separation of concerns

9175019

Add urgency and context from displayName metadata migration to usdUI …

4551ed7

…hints

Minor formatting and correctness adjustments.

444775c

Add some clarifications based on initial feedback on extended identif…

0a8d898

…iers vs. source identifiers.

Address reviewer feedback on the role of GUIDs.

f50ec52

Captured reviewer's additional notes on UsdModel and UsdMedia as relevant illustrations-- to be addressed in a subsequent working session. Just checkpointing for now.

Augment assetInfo approach with UsdModelAPI and UsdMedia uses.

00faf5e

Tightened up instance identity vs source identity section.

dc2e759

Incorporated digital engineering use case with composable bindings.

c8d438d

Incorporated context from AMT use cases and proposal.

7dbf8a2

Remove brep proposal from other branch.

f54a3cc

Correct context for IFC GlobalId in the source vs. instance identity …

639c15c

…discussion.

Condense appendix.

6ae5e1b

Incorporated reviewer notes on external queryability.

f905f16

Tone pass.

89b175f

Incorporate feedback from TAC 2026-03-06

64bbc5e

Incorporate feedback from Spiff.

ea07cba

Fix Risks numbering.

d28e347

Flesh out tradeoffs between candidate approaches.

58ce6c4

Correct IFC GlobalId terminology.

d9ea349

Correction pass over terminology.

f84aabd

Clarity pass.

ee12c50

Clearer integration of Identity Continuity and Composable Bindings

64abd05

Latest notes from Spiff.

38c95ae

github-project-automation Bot added this to OpenUSD Proposals Status Mar 8, 2026

asluk added 4 commits March 7, 2026 20:17

Update to indicate PR has been submitted

0e4260f

Incorporate feedback from Steve Ghee, and IEDT IG

6843654

Add logging notes from previous session.

c5b09f0

Incorporate Nick P feedback on opaque identifiers and vendor extensions

54e5555

asluk force-pushed the aluk/source-identifiers branch from 5b556f2 to 54e5555 Compare March 10, 2026 23:26

Readability pass on vendor extensibility

06986e0

steveghee reviewed Mar 25, 2026

View reviewed changes

Comment thread proposals/identifier_separation_of_concerns/README.md Outdated

steveghee reviewed Mar 25, 2026

View reviewed changes

Comment thread proposals/identifier_separation_of_concerns/README.md Outdated

steveghee reviewed Mar 25, 2026

View reviewed changes

Comment thread proposals/identifier_separation_of_concerns/README.md Outdated

Incorporate PLM feedback and sharpen likely direction

2cc91d8

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

steveghee reviewed Mar 25, 2026

View reviewed changes

Comment thread proposals/UsdSolid/UsdSolidBrep.md Outdated

Broaden scope example per Steve Ghee feedback

443000e

Replace manufacturing-specific framing with three industry-neutral examples of collapsing internal asset structure (manufacturing, service documentation, M&E layout). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

perfectproducts reviewed Mar 27, 2026

View reviewed changes

Comment thread proposals/identifier_separation_of_concerns/README.md

jesschimein moved this to Todo in OpenUSD Proposals Status Mar 30, 2026

asluk force-pushed the aluk/source-identifiers branch from d35b64e to c33200a Compare March 31, 2026 16:55

asluk force-pushed the aluk/source-identifiers branch from 9150faf to fea7d15 Compare April 1, 2026 17:27

asluk mentioned this pull request Apr 8, 2026

Separation of Concerns for IP Protection in USD asluk/OpenUSD-proposals#3

Closed

1 task

Acknowledge DPP semantic scope as dependent but out of scope per Pooj…

db5fe0a

…a Gupta feedback Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

asluk mentioned this pull request Apr 11, 2026

Draft: Proposal Style Guide (PR #105 structural template + prose lessons) asluk/OpenUSD-proposals#4

Draft

asluk and others added 2 commits April 15, 2026 18:09

zakmat mentioned this pull request Apr 27, 2026

REP §2.0: clarify declarative Ros*API authoring vs simulator execution artifacts RobotecAI/wip-openusd-interoperability-rep#29

Closed

asluk mentioned this pull request May 6, 2026

Source identifiers rev2: identifier packages are heterogeneously typed across all four verticals asluk/OpenUSD#7

Open

4 tasks

This was referenced May 14, 2026

Separation of Concerns for IP Protection in USD #107

Open

Boundary Representation Geometry in OpenUSD — Problem Statement #108

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This was referenced May 27, 2026

Solid Models in USD #109

Open

[WIP] Agentic workflows for standards development — a field report asluk/OpenUSD#8

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meshula mentioned this pull request Jun 2, 2026

Authorship Metadata #106

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1 task

jesschimein moved this from Todo to Draft in OpenUSD Proposals Status Jun 10, 2026

asluk mentioned this pull request Jun 27, 2026

AAS hello-world: pointing OpenUSD at the Asset Administration Shell (PR 105 applied) asluk/OpenUSD#9

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Separation of Concerns for Identifiers in USD - #105

Separation of Concerns for Identifiers in USD#105
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asluk commented Mar 8, 2026 •

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asluk commented Mar 8, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Description of Proposal

Summary

Problem statement

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Reference Links

Details

Risks

Alternate solutions

Out of Scope

Supporting Materials

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asluk commented Mar 8, 2026 •

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