Guides / Using Lumit / The application
Updated
Preview and playback
Preview is playback inside Lumit.
Press play, or space by default. The playhead will begin moving and the Viewer will update.
K stops playback.
L plays forwards and J plays backwards. Each further press doubles the speed, up to
eight times, and a press the other way steps back down. Sound plays at normal speed
forwards only.
The cache
Section titled “The cache”The cache has three tiers: VRAM, RAM and disk. You can alter the memory allocated to each of these individually under Edit ▸ Settings ▸ Preview and cache.
Lumit stores rendered frames to help speed up playback. Frames that are cached are shown by the cache bar under the time ruler: VRAM and RAM display as a green line, and frames stored on the disk are blue.
Preview resolution
Section titled “Preview resolution”Lower the preview resolution to render previews faster: full, half, third, quarter, or auto. Changing the preview resolution has no impact when exporting.
Lumit also has two preview resolution options in the Viewer bar. Every frame will render each frame in the composition, pausing audio if playback isn’t realtime. Adaptive res will instead dynamically alter the resolution to try and maintain realtime playback; if even quarter resolution isn’t enough, it will only display frames it manages to render in time.
Personally I’d normally recommend Every frame as the default option to use.
The progress bar
Section titled “The progress bar”While waiting on a slow frame, a progress bar appears on the Viewer’s bottom bar, to the left of the reading, and fills as the frame passes through decoding, building, and compositing.
Adaptive degradation
Section titled “Adaptive degradation”Under load, Lumit reduces quality on its own to keep responding. It may drop resolution while scrubbing effect values as you change them.
If playback is slow
Section titled “If playback is slow”- Lower the preview resolution.
- Let the cache fill on a first pass, then play again.
- Turn off heavy effects while you block out timing.
- Precompose a finished section so it caches as one unit.