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Speed-ramp an animation

CapCut-style speed curves: make motion accelerate and decelerate inside one event.

Speed ramping (the CapCut-style speed curve) makes motion accelerate and decelerate inside a single event without changing its duration. A Fade In still takes its 0.7 seconds — but it can crawl at the start and whip to the finish, or freeze dramatically in the middle.

Apply a ramp from the timeline

  1. Right-click any clip in the timeline.
  2. Choose Speed ramp ▸.
  3. Pick a preset — the ● dot marks the one currently applied:
PresetShape
Montagequick hit, then settle
Herodramatic slow-motion in the middle
Bulletfreeze mid-flight, then release
Jump cutslow bookends, whip through the middle
Flash incrawl, then accelerate away
Flash outburst in, land in slow motion

Right-clicking one clip of a multi-selection applies the ramp to every selected clip at once. Clips with a ramp show a small ⏱ badge.

Edit the curve node by node

Select the clip and open the Timing section of the inspector — the Speed ramp block shows the curve editor:

  • The vertical axis is the speed multiplier on a log scale: 0.1× — 1× — 10×, with 1× in the middle. Drag a node up to speed that moment up, down to slow it into slow motion.
  • Double-click the curve to add a node right on it; double-click a node to remove it (the two endpoints always stay).
  • Drag a node sideways to move when the speed change happens. While dragging, a live 2.40× readout follows the node.
  • Off removes the ramp; Custom… starts a flat 3-node curve to shape from scratch.

How it works

The curve is the playback speed over the event's own time. Under the hood the editor integrates it into a time warp — progress(t) = ∫speed / total — and composes it with the event's easing. The same math ships in the render: the compiled Python gets a _speed_ramp_rate_func(...) helper and every ramped animation's rate_func runs through it, so the canvas preview and the rendered video match exactly.

It works on every event kind: Manim animations (Create, FadeIn, …), property keyframes, transforms, matrix maps, camera moves, and graph highlights.

Easing and the ramp stack: the ramp warps time first, then the easing shapes the warped time. For the purest CapCut feel, set easing to Linear and let the ramp do all the character.