Interface overview
The timeline sits below the 3D canvas and includes:
- Playhead — Shows the current time position. Drag it to scrub through the scene.
- Ruler — Displays time markers for reference.
- Tracks — Rows for animation clips, audio files, and camera ranges, grouped under the active setup.
Playback
Use the play, pause, and scrub controls to preview your scene. Playback runs all active animation clips and audio tracks simultaneously.
Keyboard shortcuts
Animation clips
Animation clips contain keyframed movement for objects and cameras. Each clip appears as a bar on the timeline that you can move, trim, or extend.
Pre-animated USD assets
If you import a USD asset that already contains animation (a rigged character, for example):
- Open the Outliner panel.
- Expand the active setup, then its Objects folder, then the asset.
- Expand its Animation node.
- Hover the row and click + (“Add to timeline at playhead”) to add the clip at the current playhead position, at normal speed.
- Toggle Keyframes on for that object.
Without Keyframes enabled, pre-animated USD assets may render correctly in the browser but sit frozen on playback in the Spark iOS app.
Adding a clip this way is undoable with Cmd+Z, like any other timeline edit.
Audio tracks
Add audio files to the timeline for reference during camera planning. Audio tracks display waveforms so you can visually sync camera movement or scene events to sound cues. Unlike objects and cameras, audio tracks are not scoped to a setup.
Camera ranges
Camera ranges appear on the timeline as highlighted sections, each corresponding to a camera in the active setup. Adjusting a camera range changes that camera’s start and end time. Only the active setup’s cameras and objects are shown; switch setups to see a different set of ranges.
