Enables the spline tween mode for moving Actors along editable tracks. The Spline Tween Mode edit options are separated into the Track tab page and the Direction tab page.
Note that Spline Tween Mode enables you to view and edit the entire animation at once without stepping from frame to frame! Frame->Next (>) and Frame->Previous (<) can be used to step through the frames to watch the selected Actor move from point to point along its track.
Only Tween or Spline Tween movement timeline types can have a track, any other movement timeline types (e.g. Look At) cannot enter Edit Track mode. If they are Tween the segments in the track will be straight lines, if they are Spline Tween the segments will be curved. If the selected Actor has no movement timelines, appropriate timelines will be added automatically when Edit Actor Track mode is entered for the first time.