Use the Sequence lane’s Frame property to scrub or keyframe a frame-folder animation with a meaningful clip duration.
Where: Drop/import an image-sequence folder → select the sequence → Timeline → Sequence → Frame.
Key ideas
- An image sequence is a clip: The sequence manifest describes ordered frames. Its natural clip duration is frame count divided by source FPS; when no valid FPS is supplied, the sequence uses 24 FPS. A dropped sequence now gets playback configuration instead of behaving like an inert still.
- Frame numbers, not guessed percentages: For a readable manifest with more than one frame, the timeline exposes a Frame row from zero to frameCount minus one. The action is imageSequencePlayback with track parameters unit=frames and frameCount so frame 30 means frame 30, not 30 percent.
- Safe fallback: A missing/unreadable manifest or a single-frame sequence falls back to Sequence playback from 0 to 100 percent. That fallback keeps an editing control available; it does not prove the source contains a playable multi-frame animation.
Steps
- Import or drop the folder as an image sequence, then confirm its frames and FPS rather than treating the first thumbnail as the entire result.
- Select the sequence and open its collapsible Sequence lane in the timeline.
- Add a Frame key at the intended start, for example frame 0, and another at the intended end, for example frame 119 for a 120-frame sequence.
- Choose linear timing for steady source playback, or change easing/key spacing deliberately to create a speed ramp, hold, or reversal.
- Scrub the timeline and compare the visible frame with the numeric value. Check clip trims and the natural duration.
- Preview and render a short section. Allow the sequence frames to load before judging the capture.
How source FPS and animation timing interact
The source FPS gives the clip a natural duration. Keyframes can intentionally redistribute those source frames across a different timeline interval. Keep the two decisions distinct: changing the clip’s FPS is not the same operation as easing the Frame property between two keys.
AI/tool authoring contract
- Use imageSequencePlayback for the property.
- When authoring in frames, include params.unit="frames" and the actual frameCount through the relevant timeline tool contract.
- Read the current manifest/frame count first; do not infer it from the filename of one frame.
- The editor and video assistant now advertise the frame-based sequence property.
Troubleshooting
The timeline only offers a percent control.
Check that the manifest is readable and contains more than one frame. A missing or single-frame manifest intentionally uses the fallback.
Frame 30 shows the wrong point.
Verify that the track uses frame units and the actual frame count; a percent-based track interprets the same number differently.