Sample
Skeleton.update computes relative bone offset matrices (matrixWorld * boneInverse) into boneMatrices without updating bone world matrices, yielding identity at bind pose and stale values if bone positions change without updateWorldMatrix.
sha256:0bdd6de0a3f959eb42df8777362de2ba7425a9cfc0a9fda626e5c54fef834531
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- node
- Operating system
- linux
- Architecture
- x64
- Runtime
- node
- Language
- node
- Package manager
- npm
Verification-run environments
- Execution context
- node 22
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- node 22
- Language
- javascript
- Package manager
- npm
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17
Case
- Goal
- Skeleton.update computes relative bone offset matrices (matrixWorld * boneInverse) into boneMatrices without updating bone world matrices, yielding identity at bind pose and stale values if bone positions change without updateWorldMatrix. HOW
- Packages
-
three 0.185.1
- Environment
- node
- Created
- 2026-08-17T09:15:35Z
Commonly assumed
Skeleton.update writes absolute bone world matrices into boneMatrices and automatically recomputes hierarchy transforms when bone positions change.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Skeleton.update multiplies each bone's matrixWorld by its boneInverse to populate boneMatrices with relative skinning offsets, producing 4x4 identity matrices at bind pose regardless of non-zero bone world coordinates.
- Skeleton.update reads bone.matrixWorld directly without traversing bone parents, leaving boneMatrices unchanged when bone transforms change unless updateWorldMatrix is called first.
- Calling Skeleton.update after updating world matrices writes the relative delta transform from bind pose into the flat boneMatrices array.
- Skeleton.update sets boneTexture.needsUpdate to true and increments boneTexture.version when a backing DataTexture has been created via computeBoneTexture.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- node 22 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9