StageTrace helps pipeline TDs and USD tools engineers turn a surprising composed result into the value source, losing opinions, causal composition path, and a conservative next action.
01 / The problem
A property stack can contain specs that do not author the winning value. A time query can resolve through samples, clips, splines, fallback, or a block. Visibility can be inherited from an ancestor. The useful answer is not merely “the value is X.”
StageTrace is for people who already know USD and need a faster, reviewable path from a symptom to the actual source evidence.
02 / Three useful questions
$ why
{
"command": "why",
"status": "ok",
"data": {
"resolvedValue": "invisible",
"sourceKind": "authoredDefault",
"winner": { "layer": "<ASSET>/lighting.usda", "arcType": "reference" },
"safeEditRecommendation": { "canEdit": true, "action": "authorSessionOverride" }
}
}Resolve one property and correlate its value source, competing opinions, causal arc, and safe action.
Open JSON Schema$ visibility
{
"command": "visibility",
"status": "ok",
"data": {
"computedVisibility": "invisible",
"blockingOpinion": { "path": "/World/Car.visibility", "value": "invisible" }
}
}Compute effective visibility and identify the actual invisible ancestor and opinion.
Open JSON Schema$ explain
{
"command": "explain",
"status": "ok",
"data": {
"mode": "property",
"probe": { "stageRevision": 1 },
"property": { "resolvedValue": "invisible" },
"visibility": { "computedVisibility": "invisible" }
}
}Combine property, composition, visibility, layer, and editability context from one stage snapshot.
Open JSON Schema03 / How it works
OpenUSD resolves the value and visibility facts. StageTrace reads the same stage snapshot, correlates resolve information with property-stack and composition evidence, classifies what can safely be edited, and formats the result for a human or pipeline.
Resolved through bundled OpenUSD, cross-checked against direct OpenUSD queries, and emitted as schema-validated JSON.
JSON Schema validates output structure. It does not prove semantic truth. Truth confidence comes from deterministic edge-case fixtures, direct OpenUSD differential assertions, and optional real-asset semantic sampling.
Query the target, time, and load policy through bundled OpenUSD.
Match the resolved source to real authored sites and the causal composition node.
Recommend only the non-destructive actions the current edit model supports.
Return readable text or stable, schema-validated JSON.
04 / Current boundary
05 / Asset boundary
StageTrace runs against files on your machine. The planned product does not upload USD assets, layers, textures, or paths to a hosted analysis service. The research form below is separate and stores only the answers you choose to submit.
06 / Join the research
This first round is five short conversations about the problem, platform, and workflow—not a sales call and not a claim that an interview validates correctness. A private binary comes later, only after the distribution gates and real interest.