Purpose
Use this exact feature skill when the selected profile, validation report, or user request names FET_033_STANDARD. It repairs or stages Metadata conformance (thumbnail and nested provenance metadata) without drifting into another runtime contract.
Default to FET_033_STANDARD@0.4.0 when the user asks for this feature without a version. Use an older version only when the profile, validation report, or user explicitly pins it. If the report names a different FET_###_RUNTIME feature, switch to that feature's matching skill before editing.
Source of Truth
Before changing an asset or package, read:
nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/features/FET_033_STANDARD-0.4.0.json(latest)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/features/FET_033_STANDARD-0.3.0.json(preserved)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/features/FET_033_STANDARD-0.2.0.json(preserved)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/features/FET_033_STANDARD-0.1.0.json(preserved)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/features/FET_033_STANDARD.mdnv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/capabilities/core/sim_ready/requirements/thumbnail-exist.md(SR.002)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/capabilities/core/sim_ready/requirements/nested-simready-metadata.md(SR.003)nv_core/tiers/simready_foundation_tier_core/simready/foundation/tier_core/capabilities/core/sim_ready/requirements/metadata-union.md(SR.004)
Treat the selected JSON manifest as authoritative for dependencies and requirement IDs. Use the feature markdown for human-readable contract details, requirement links, samples, benchmarks, and adapters.
Feature Versions
| Version | Dependencies | Requirements |
|---|---|---|
0.1.0 |
FET_031_STANDARD@0.1.0 | SR.002 |
0.2.0 |
FET_031_STANDARD@0.1.0 | SR.002, SR.003 (nested SimReady_Metadata) |
0.3.0 |
FET_031_STANDARD@0.1.0 | SR.002, SR.003 (stricter nested provenance fields) |
0.4.0 |
FET_031_STANDARD@0.1.0 | SR.002, SR.004 (same 0.3.0 fields; USD/sidecar union) |
Workflow
- Confirm the input exists and identify the exact selected feature/version from the profile TOML, validation report, or user request.
- Load the selected
FET_033_STANDARDmanifest and the feature markdown before editing. - Load requirement docs linked from the feature markdown for every reported failing requirement.
- Create or use a staged output location unless the user explicitly asks for in-place edits.
- Repair only the requirements listed by the selected
FET_033_STANDARDmanifest and its dependencies. - Rerun the same profile gate or the narrowest available feature/capability validation gate. If runtime evidence is required and unavailable, report that limitation instead of claiming a pass.
- Summarize the selected
FET_033_STANDARDversion, changed files, validation evidence, and the first remaining blocker or next exact feature gate.
Feature Guidance
- Repair only the requirements listed by the selected
FET_033_STANDARDmanifest and its dependencies. - For
SR.002, ensure a representative PNG thumbnail exists at.thumbs/256x256/<asset_filename>.pngnext to the root asset. - For
SR.003atFET_033_STANDARD@0.2.0/@0.3.0, the published feature contract places required fields inside root-layercustomLayerData.SimReady_Metadata. - For
SR.004atFET_033_STANDARD@0.4.0, author required provenance fields in the USD/sidecar metadata union:author,asset_name,asset_type,asset_license,category,source_file, andusd_date_generated. Fields may live in root-layercustomLayerData(optionally insideSimReady_Metadata), in<usd_stem>.jsonbeside the root USD, or split across both. Neither location is required on its own, but a field must not be authored in both. - For
SR.003at version0.3.0andSR.004at version0.4.0, also author these required asset-descriptive fields (nested inSimReady_Metadataat0.3.0; in the USD/sidecar union at0.4.0):qcode(string): Wikidata Q-Code for the asset's general category, a capitalQfollowed by one or more digits (for exampleQ42177).rigid_body_count(int): non-negative count of rigid bodies in the asset.asset_extents(float3): asset bounding-box size in meters as XYZ, with non-negative components.mass(float): asset mass in kilograms, strictly positive.
- Do not author
SR.0030.3.0/SR.0040.4.0descriptive fields with placeholder or fabricated physical values. Deriverigid_body_count,asset_extents, andmassfrom the actual asset (rigid-body prims, computed bounds, and authored mass); if a value cannot be derived, report it as a blocker instead of guessing.
How to Generate Metadata
The SR.003 / SR.004 requirements are declarative (they check the end state in
nested SimReady_Metadata or the USD/sidecar union), so use the
bundled helper to populate provenance fields. The helper
only derives what the stage can prove and never fabricates values. You may
write the helper output into customLayerData.SimReady_Metadata, into
<usd_stem>.json, or split across both.
Helper script: assets/scripts/extract_simready_metadata.py (run with a USD-core
Python; the same interpreter used to run SimReady validation works).
- Derived deterministically from the stage:
asset_extents(float3, meters) from the default prim's world bounding box, converted with the stagemetersPerUnit.rigid_body_count(int) by counting prims withUsdPhysicsRigidBodyAPI.mass(kg) by summing authoredphysics:masson prims withUsdPhysicsMassAPI; reported asnull(needs input) when none is authored.qcode(Wikidata Q-Code) from the default (root) prim's authored Wikidata semantics. Both encodings are read: the newerUsdSemanticssemantics:labels:<taxonomy>token array (taxonomy name containingqcode) and the legacy multi-applysemantic:<instance>:params:semanticDatawith awikidata_qcodetype. Reported underneeds_inputwhen the root prim has no Q-Code semantic. Pass--set qcode=<Qxxxx>to override or supply one.
- Not derivable here (must be supplied, never invented):
author,asset_name,asset_type,asset_license,category,source_file,usd_date_generated. Pass them with repeated--set KEY=VALUE.
Typical usage:
# 1) Inspect what can be derived (no writes):
python assets/scripts/extract_simready_metadata.py <asset.usd> --dry-run
# 2) Stamp derived fields (incl. qcode from root-prim semantics) plus
# caller-supplied strings into a staged copy:
python assets/scripts/extract_simready_metadata.py <asset.usd> \
--output <staged/asset.usd> \
--set author=<author> --set asset_name=<name> \
--set asset_type=<type> --set asset_license=<license> \
--set category=<category> --set source_file=<source> \
--set usd_date_generated=<date>
# add --set qcode=<Qxxxx> only to override the derived value or when the
# asset carries no Wikidata Q-Code semantic.
The helper keeps existing metadata values unless --overwrite is passed, writes
a JSON/markdown report with --report/--markdown-report, and lists every field
still needing input under needs_input. Treat a null mass or a missing
asset_extents as a blocker to resolve (author UsdPhysicsMassAPI / fix
geometry, or supply the value) rather than stamping a fabricated number.
Mass Plausibility Check (advisory)
Beyond presence/type validation, the helper reports whether the authored mass
is physically plausible for the object. This is advisory only: it emits warnings
and a verdict, never a hard failure, because plausible mass depends on what the
asset represents in the real world.
Every run includes a mass_check block with per-body and aggregate solid volume
(computed from mesh geometry), and the implied density mass / volume. Two
signals:
- Deterministic (automatic): an implied density outside the physically
possible range (
1–23000kg/m^3, i.e. lighter than any real solid or denser than osmium) is flagged as a likely mass or unit error (for example mass authored in grams, or a cm^3/m^3 mix-up). This needs no external knowledge. - Agentic (recommended for the real-world judgement): decide a plausible mass range for the object from its type and dimensions — and, when available, a render or the source mesh — then pass it back so the report records the comparison and rationale:
python assets/scripts/extract_simready_metadata.py <asset.usd> --dry-run \
--expected-mass-min <kg> --expected-mass-max <kg> \
--mass-rationale "office chair, mostly plastic + steel base, ~5-10 kg"
The verdict is plausible (inside the range), review (outside but within
~100x), or implausible (>=100x off, almost certainly an authoring/unit error).
Because this is a real-world judgement, a vision-capable agent should set the
expected range from visual/mesh evidence; if the agent cannot make that
judgement, report it as manual review rather than asserting the mass is correct.
Do not change the authored mass to satisfy this check — surface a warning and
let a human or the asset author correct the source value.
- Do not add schemas, metadata, or runtime behavior for a sibling runtime feature.
- Report missing runtime/tooling evidence as a validation limitation instead of claiming a pass.
Report Fields
| Field | Meaning |
|---|---|
feature |
Exact feature ID and version, for example FET_033_STANDARD@0.4.0. |
input |
Source asset, package root, or package definition inspected. |
output |
Staged output path, or in-place only when explicitly requested. |
requirements_repaired |
Requirement IDs repaired in this pass. |
validation |
Command or inspection used to verify this exact feature. |
status |
passed, failed, skipped, or blocked. |
next_step |
The next exact feature skill or user/runtime evidence needed. |