Response

The response body is a glTF 2.0 document.

Content-Type is model/gltf+json for JSON glTF or model/gltf-binary for .glb, per Accept negotiation.

What's in it

• A nodes[] hierarchy and skins[] definition mirroring the request's skeleton (joint names preserved).
• One animations[] entry per generated sample, named sample_0, sample_1, … Each animation has dense per-frame channels with LINEAR interpolation for joint rotations and the root translation.
• Buffers / bufferViews / accessors backing the animation data. In the JSON variant, buffers are embedded as data: URIs; in the binary variant they live in the GLB binary chunk (no base64 overhead).
• An extensions.MMCP_motion block carrying motion metadata that doesn't fit cleanly in glTF. The corresponding extensionsUsed entry is "MMCP_motion".

Joint set scope

Clients SHOULD treat the response's joint set as authoritative for the joints listed and leave any additional bones in the user's actual rig (IK controls, twist bones, fingers, face) to client-side rig logic. The response only animates joints that were sent in the request's skeleton.joints.

extensions.MMCP_motion

{
  "version": "1.0",
  "model": "kimodo-soma-rp",
  "fps": 30.0,
  "canonical_to_request": {
    "Hips": "mixamorig:Hips",
    "LeftFoot": "mixamorig:LeftFoot"
  },
  "samples": [
    {
      "name": "sample_0",
      "num_frames": 150,
      "chunk_boundaries": [],
      "foot_contacts": {
        "LeftHeel":  [true, true, false],
        "LeftToe":   [true, true, true],
        "RightHeel": [false, false, true],
        "RightToe":  [false, true, true]
      }
    }
  ]
}

Field	Type	Notes
version	string	Protocol version that produced this response
model	string	Echoed model id
fps	number	Frame rate of the animation
canonical_to_request	{ canonical_joint: request_joint } | null	Present only when the server retargeted the canonical skeleton to the client's skeleton. Maps the canonical joint name (used internally) to the request's joint name (used in samples[].foot_contacts). Servers with supports_retargeting: false omit this field
samples[].name	string	Matches the corresponding animations[].name
samples[].num_frames	int	Frame count
samples[].chunk_boundaries	int[]	Frame indices at which the server stitched internal chunks (relevant when the model declares chunking: "stitched"). Empty array when the request fit in one chunk
samples[].foot_contacts	{ joint_name: bool[] } | { "$accessor": int } | null	Per-frame contact state, keyed by joint names from the request's skeleton.joints. For long clips, MAY reference an accessor (uint8 booleans, length num_frames × len(joints)) via { "$accessor": <accessor_index> }; the joint-name → channel-index mapping then lives in samples[].foot_contact_joints: string[]

Clients that don't need the metadata can ignore the extension entirely and still get a valid glTF.