The curve editor

Shape how an animated value travels between its keyframes.

A keyframed parameter draws its in-between values as a curve. The curve editor is where that curve is shaped: how fast the motion starts, where it slows, whether it glides or snaps. The same keyframes can read completely differently.

What you are looking at

Each animated value is a line through its keyframes, plotted as value (up) over time (across). The dots are the keyframes. The line between them is every frame in between.

Every keyframe carries two handles, one reaching back toward the previous keyframe and one forward to the next. Dragging a handle bends the curve near that point. A flat, level handle eases the value to a gentle stop. A steep handle means it is still moving fast as it arrives.

A handle sitting at zero length is not drawn, so a smoothed first keyframe shows only its forward handle and the last only its backward one. A parameter with a single keyframe shows neither.

A Vec2, Vec3 or Colour value gets one curve per channel (x, y, z, or r, g, b, a), each editable on its own, so the X of a position can ease differently from its Y. Numbers and toggles have a single curve.

Outside the keyframe range the value is held. It stays parked at the first keyframe before the animation starts and at the last keyframe after it ends. There is no extrapolation past the ends.

Handle types

Each keyframe carries a handle type, and there are five. Two of them shape the handles for you:

Aligned, Free and Vector are records of intent rather than constraints. They leave the handles exactly where they are, so switching to one changes nothing by itself, and nothing afterwards holds a Vector handle pointed at its neighbour or an Aligned pair in line. What they mark is a curve you are shaping by hand.

The type is cycled, not picked. Double-click a keyframe, or select keyframes and press V, and each press steps one place through Free, Aligned, Auto, Auto Clamped, Vector and back to Free. The names are not printed in the editor.

Auto and Auto Clamped handles are computed at one moment only: when a keyframe is set on that parameter. Switching a type does not reshape anything on the spot, and neither does dragging a keyframe to a new time, so a curve can sit un-smoothed after a retime until the next K.

That recompute is also what discards hand-shaped handles. Dragging a handle on a keyframe that is still Auto leaves its type alone, so the next K anywhere on that parameter overwrites the shape you drew. Cycle the keyframe to Free first and the drag survives. Re-keying is not a way to force a resmooth either: K replaces the keyframe outright and resets it to Auto.

Working in the editor

Click a keyframe or a handle to select it, Shift-click to add to the selection, and drag across empty space to box-select. Then:

Scroll or pinch to pan and zoom. Both axes move together.

Easing in and out

Easing is the shape of acceleration, and it comes out of the handles rather than a menu. There is no preset list.

Shaping motion in practice

Four moves that come up constantly:

Curves vs expressions

Keyframes and the curve editor are for hand-authored motion you can see and feel. For motion driven by a formula, a constant wobble or something tied to the clock, an expression is the better tool. Both can be mixed across a project, chosen per parameter.

The recorder captures a knob, fader or other live input straight into keyframes on a curve, which you can then clean up here.

See also