Character rig

Publish a canonical asset-space skeleton contract; engine adapters own any runtime conversion.

Minimum humanoid chain: pelvis, spine, neck/head, clavicle, upperArm, lowerArm, hand, thigh, shin, foot. Extra spine joints, twist bones and toe/ball joints are capabilities, not universal requirements. A foot-lock implementation may target a toe/ball joint when present, otherwise a published foot/ankle contact marker. Do not silently invent a missing joint in runtime code.

Bind in a documented rest pose with a documented forward/up convention. Keep left/right naming deterministic. Sockets such as weapon_r, weapon_l, bow, camera_pivot and hit_flash are optional published attachments; consumers must declare which are required.

The exported rig records scale/unit metadata and facing. Importers may convert once at the adapter boundary; do not hide repeated 90°/180° or scale corrections in gameplay code.

Accept

Retarget a neutral locomotion clip and verify left/right limbs, root height and facing. Attach every required socket and confirm it survives export/import. Test a rig both with and without toe joints when foot locking is supported; missing optional joints must degrade through the declared fallback rather than disabling the whole character.

Reusable clip compatibility

Use the retarget protocol for cross-rig motion libraries: semantic mapping, rest-pose correction, explicit root-displacement ownership and support-relative contact probes. Publish compatibility per clip/rig/version; missing required chains block only the affected pair. Neither matching bone names nor a neutral screenshot proves animated compatibility.