usd-value-resolution

name	usd-value-resolution
description	Use this skill when implementing or verifying USD value resolution over already composed opinion stacks.
metadata	{"author":"NVIDIA"}

usd-value-resolution

Use this skill when implementing or verifying USD value resolution over already composed opinion stacks.

Spec Sources

• aousd/specifications-public@v1.0.1:core/1.0.1/core_spec.md section Value Resolution
• aousd/specifications-public@v1.0.1:core/1.0.1/core_spec.md section Fallback Value Resolution for Attributes

Pinned tag / commit: v1.0.1

Provides

• A value_resolution capability
• A resolver boundary over strong-to-weak typed opinion stacks
• Attribute defaults, blocks, time samples, splines, clips, and schema fallbacks
• Metadata resolution for ordinary fields, special fields, dictionaries, and generic listOps
• Relationship target forwarding and raw attribute connection target queries

Contract

This skill owns contracts/handles/value-resolution.handle.json and contracts/spec-coverage/value-resolution.coverage.json.

The resolver consumes target-native opinion records. It must not build composition indexes, inspect parser-local USDA syntax, parse canonical JSON dumps as durable storage, or populate stages. Composition, stage population, and value resolution are separate graph nodes.

When resolving attribute values, walk the composed opinion stack in strength order and apply AOUSD value-resolution rules. Default-time queries look for authored default values and then schema fallbacks. Timed queries apply retiming, query authored timeSamples, then splines, defaults, value clips, and fallbacks according to their AOUSD strength and precedence rules.

valueBlock and blocked time samples stop weaker authored values. If schema fallback acquisition produces a fallback, return it; otherwise return the unauthorable empty sentinel.

Metadata resolution returns the strongest authored value for ordinary fields, except for fields with special AOUSD rules. Implement custom, specifier, typeName, variability, recursive dictionaries, generic listOps, root-layer-only layer metadata, relationship target forwarding, and raw connection target resolution.

Boundary Guards

Do not consult OpenUSD behavior.

Do not perform composition, namespace remapping, asset resolution, parser syntax handling, or stage population in this skill.

Do not claim value-resolution behavior from a source provider unless the source provider supplies the strength-ordered opinions, schema fallback context, layer retiming, and clip context needed by this resolver.

Test Obligations

• default value resolution walks weaker opinions when stronger opinions lack a default value
• value blocks and blocked time samples stop weaker values
• timed queries cover exact samples, held interpolation, linear interpolation, default fallback, and retiming
• schema fallback acquisition covers typed schemas, applied schemas, and the empty sentinel/default-metadata fallback
• metadata covers ordinary strongest-authored fields, custom, specifier, typeName, variability, dictionaries, listOps, and root-layer metadata
• spline cases cover held, linear, curve, value-block, and extrapolated segments
• value clips cover strength, active clips, times mapping, manifest defaults, and missing-clip interpolation
• relationship targets cover raw and forwarded targets; connections remain raw
• all cases in goldens/unit/usd-value-resolution/value-resolution.json