Command · Track Motion

track.transform

Tracks a region of a clip ("region": {x, y, width, height} 0..1 of the frame, {"mask": id}, or {"detect": "face"} once a detector is installed) and keys a clip's Motion with it (one undo step): "follow" moves "target" with the region (position; with the similarity model also scale and rotation), "stabilize" keys the tracked clip so the region stays still.

• v1
• Capability EditSequence
• Tool track_transform

Request

{
  "command": "track.transform",
  "params": {
    "clip": 42,
    "region": {
      "height": 0.2,
      "width": 0.2,
      "x": 0.4,
      "y": 0.3
    },
    "target": 57
  }
}

Parameters

clipinteger | object (1..)Required

The tracked clip. A clip id, or {"track", "time"} for the clip there.

direction`forward` | `backward`

Default forward.

framesinteger (1..)

Track at most this many frames (1 = one step). Default to the clip's end.

minConfidencenumber (0.0..1.0)

Stop where the confidence falls below this. Default 0.3.

mode`follow` | `stabilize`

Default follow with a target, else stabilize.

model`translation` | `similarity` | `affine`

What the region may do: move; move, turn and scale; or any affine. Default similarity.

regionobjectRequired

What to track.

sequenceinteger (1..)

Sequence id; only needed when the project has several.

targetinteger | object (1..)

The clip that follows. Default the tracked clip (stabilize). A clip id, or {"track", "time"} for the clip there.

timeinteger | string

Where to start (inside the clip). Default the clip's first frame (backward: its last). Timecode in the sequence's rate ("00:01:02:03") or ticks.

workingWidthinteger (64..4096)

Width of the pictures the tracker looks at. Default 640.

Discussion

Run it with wabcut-cli cmd <project> --json, from an MCP client as track_transform, or from an extension. See Edit commands for requests, references and results.