Optional ReadonlylocalSixteen column-major elements; only with matrixAutoUpdate: false.
Optional ReadonlymatrixAbsent means true — the engine owns the local matrix (§7).
Optional ReadonlypivotPivot the rotation and scale act about; absent means the node origin.
Optional ReadonlypositionLocal translation; absent means the origin.
Optional ReadonlyrotationLocal rotation; absent means identity.
Optional ReadonlyscaleLocal scale; absent means (1, 1, 1).
A node's local transform (§7).
Every field is optional and absent means default: the identity transform serializes to
{}(and is then dropped from the node entirely), which is what makes a hand-edited scene file readable and its diffs small (§79).matrixAutoUpdate: falseis §7's user-owned matrix: the authored position/rotation/scale/pivot are still recorded (they are the node's stored state, stale or not — §7 never back-derives them) and TransformDocument.localMatrix carries the sixteen column-major elements the user wrote. A document that supplieslocalMatrixwhile leavingmatrixAutoUpdateat its default is refused rather than silently stripped: under auto-update the engine owns that matrix and would recompose over it.