OptionaldurationClip length in seconds. Defaults to the largest of every track's last
keyframe time, every event's time, and 0 — the natural extent of the
authored content. Must be finite and non-negative.
OptionaleventsMarkers on the clip's timeline. Copied and sorted by time; see AnimationClip.events for the tie-break rule.
Clip name, used for lookup and diagnostics.
The clip's tracks, in evaluation order. Copied; the tracks themselves are shared, which is safe because a track is immutable data.
Construction inputs for AnimationClip.