Sub-track reference
Every sub-track a layer can show on the Timeline: what it animates, which layer types have it, and whether it supports a Loop Group.
Click a layer's disclosure triangle on the Timeline and its main row expands into sub-tracks: one row per animatable property, each with its own keyframes and its own easing. Which sub-tracks appear depends on the layer type: a Shape layer shows Vertices and Style, a Camera shows Depth of Field and Point of Interest, a bone layer shows one group per bone.
By default the Timeline only lists sub-tracks that already own a keyframe. Turn that filter off from the Timeline toolbar to see every sub-track a layer type is capable of, keyed or not. The filter reaches every animatable row, bone channels and the bone group itself included; only the structural rows are exempt, meaning the layer's own row, the cell strip, Symbol Playback and the group markers.
Transform and per-layer sub-tracks
| Timeline name | What it animates | Shown on | Loop Group |
|---|---|---|---|
| Vertices | The full Bezier path: points, the closed flag, and any extra contours (holes) | Shape layers, and a Drawing layer's active cell | Yes |
| Position | X/Y position, plus the motion-path handles you drag in the viewport (Position Z is stored but not rendered) | Any layer except a bone | Yes |
| Rotation | Z rotation (roll), in degrees | Any layer except a bone | Yes |
| Scale | X/Y scale | Any layer except a bone | Yes |
| Anchor | The anchor point the layer transforms around | Any layer except a bone | Yes |
| Opacity | Layer opacity | Any layer except a bone | Yes |
| Rotation X (tilt) | 3D X tilt, independent of the Z rotation above | Any layer except a bone | No |
| Rotation Y (pan) | 3D Y tilt | Any layer except a bone | No |
| Blend | The blend radius of a liquid or boolean group | Group layers | Yes |
| Mesh | Per-vertex mesh deform, in the mesh's own local space | Mesh layers | No |
| Z-Order | A relative draw-order hop among sibling layers | Any layer with layer ordering turned on | No |
| Switch: (child name) | Which child layer is the active variant | Switch layers and variant parents | Yes |
| Zoom | How far the camera is zoomed in, 0.1 to 10 | Camera only, inside the Transform group | No |
| Depth of Field | Camera depth-of-field blur strength | Camera only, inside the Transform group | No |
| Point of Interest | The camera's track point, a 3D position | Camera only, inside the Transform group | No |
Style, effects, Follow Path and bones
A few properties do not get a single fixed sub-track. Instead the Timeline groups them under a disclosure header, with one leaf row per parameter.
| Group | Leaf rows | Shown on |
|---|---|---|
| Style | Fill, Stroke, Expose and Dash, one row each. Stroke width rides with Stroke, the two write-on percentages with Expose | Shape layers, and the active cell of a Drawing layer |
| Follow Path | The parameters of the Follow Path constraint | Any layer with a Follow Path target set |
| Layer Effects | One sub-group per enabled effect, then one row per animatable parameter of that effect | Any layer with Layer Effects applied |
| A bone's own group, named after the bone | Angle, Stretch and Position, one row each, then the bone's Inverse Kinematics, Angle Dynamics, Position Dynamics and Scale Dynamics parameter groups | Bone layers, one group per bone |
A bone's three channels are separate rows, not one merged diamond: Add Keyframe on a row keys that channel alone, while the same command on the bone's group header keys the whole pose at once. On a stretched child bone the Position row is inactive, because its origin is derived from the parent chain; the row is dimmed and takes no new keys, though keys already on it still show and can be deleted.
The three Dynamics groups hold spring parameters, not the channels above them. They are named Angle Dynamics, Position Dynamics and Scale Dynamics so they cannot be mistaken for the Angle, Stretch and Position rows.
The leaf rows of these groups do take a Loop Group: a Style parameter, a Layer Effects parameter, a Follow Path parameter and a bone parameter can each carry one, exactly as the fixed sub-tracks above can. What cannot is a bone's own Angle, Stretch and Position rows, along with Mesh, Z-Order and the camera channels, because nothing remaps those.
Loop Group vs. Pre/Post Behaviour
Loop Group is a per-sub-track cycle: right-click a sub-track with two or more keyframes selected and choose Loop Group, then Loop, Ping Pong or Hold. The keyed span repeats forward from its last keyframe for as long as the layer is on screen.
This is a different feature from a layer's Pre-Behaviour and Post-Behaviour, which apply to the whole layer outside its keyed range, not to one sub-track. A layer can have both at once, and they do not interact: a Loop Group keeps cycling on its own sub-track regardless of what Pre/Post Behaviour is set to.