Tangent Types

You can adjust the tangent type of the Bezier transforms. This means you can adjust the interpolation between keyframes to create particular motion effects. By manipulating tangent types, you can make something hesitate, speed up, slow down, or even stand still.

Each key has two tangents: one to define the interpolation before the key, and a second to define interpolation following the key.

Tip: You can also set the default tangent type with the Default In/Out Tangents For New Keys flyout. By doing so, each new key created with Set Key Mode or Auto Key Mode uses the curve interpolation set by the default tangent type.
Smooth

Creates smooth interpolation through the key.

Linear

Creates linear interpolation at the key.

A Linear tangent affects the curve near the key only. Full linear interpolation between two keys occurs only when the Out tangent of the first key and the In tangent of the next key both use Linear tangents.

Step

Creates binary interpolation from one key to the next. Step tangents require a matched set between the Out tangent of one key and the In tangent of the next key.

Choosing Step for the In tangent of the current key also sets the Out tangent of the previous key to Step. Likewise, choosing Step for the Out tangent of the current key also changes the In tangent of the next key to Step.

Using Step tangents, the outgoing value of a key is held constant until the time of the next key is reached. The value then abruptly jumps to the value of the next key. Use this tangent when you want to animate On/Off switching or instantaneous changes from one value to the next.

Slow

Causes the interpolated rate of change to slow down around the key. A slow In tangent decelerates as it approaches the key. A slow Out tangent begins slow and accelerates as it leaves the key.

Fast

Causes the interpolated rate of change to speed up around the key. The effect is the opposite of using slow. A fast In tangent accelerates as it approaches the key. A fast Out tangent begins fast and decelerates as it leaves the key.

Spline

Displays adjustable tangent handles (in black) at the key in Track View - Curve Editor mode.

Auto Tangent

Displays a smooth interpolation type designed to eliminate overshoot. Tangent slopes automatically take the most direct route to the next key value. Handles are displayed in Track View - Curved Editor (in blue); if you edit them the tangent type automatically switches to Spline (see preceding).