NLA strips

NLA (non-linear animation) turns keyframes into named actions, like a walk cycle or a wave, that you place as strips on tracks under a character. Strips can be moved, repeated, scaled and blended without touching the keyframes inside them.

Making an action

1. Select keyframes of a character and its parts.
2. Right-click the timeline and choose NLA… → Push down to action.

The keyframes move into a new action and are replaced by a strip at the same place, on an NLA track under the character. Keyframes on the character itself become the action’s root motion.

Actions stay in the project even when no strip uses them. NLA… → Remove unused actions cleans them up.

Tracks and strips

Each character can have several NLA tracks. Upper tracks override lower ones, and hiding a track mutes it. Add one with NLA… → Add NLA track, and place an existing action at the playhead with NLA… → Add strip.

Strips work like keyframes: click to select, drag to move, copy, paste and delete them. Right-click for more:

Option	What it does
Cut strip at marker	Splits the strip at the playhead. Repeating strips are cut at the nearest repeat.
Duplicate strip	Places a copy right after the strip.
Make action cyclic	Makes the action end on its first pose, so it loops seamlessly.
Linear root motion	Sets linear interpolation on the action’s root motion.

A part that has keyframes of its own ignores NLA strips, so you can still animate it by hand.

Strip properties

Select a strip to edit it in the frame editor:

Property	What it does
Action	The action the strip plays. The name field below renames the action.
Action frames	The part of the action the strip plays.
Repeat	How many times the strip plays the action.
Scale	Plays the action slower or faster. The reset button sets it back to 1.
Extrapolation	Hold keeps the last pose until the next strip on the track. Nothing stops at the end of the strip.
Auto blend	Sets the blend from the strips it overlaps on lower tracks.
Blend in and out	Frames to fade the strip in and out over the tracks below.
Exclude root from cyclic	Leaves the root motion alone when making the action cyclic, so a walk keeps moving forward.

Every NLA edit can be undone and syncs in co-op.