Re-track the plane after clearing the keyframe

From the math point of view there're two cases:

- Clearing the keyframe between two other ones.

  In this case tracker will first track plane from
  left keyframe to right one without doing any kind
  of blending. This will make plane stick to the
  actual plane motion, but lead to possible jump
  at the right keyframe.

  Second step is to track from the right keyframe
  to the left one with blending. This gives nice
  transition at the point of second keyframe and
  this mimics situation when you've been setting
  keyframes from left to right.

- Clearing left-most/right-most keyframe.

  In this case it's enough to only re-track the
  plane without blending from the neighbor keyframe
  without blending.

1 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/editors/space_clip/tracking_ops.c b/source/blender/editors/space_clip/tracking_ops.c
index 59101b24ad8..a4cd1e1ccad 100644
--- a/source/blender/editors/space_clip/tracking_ops.c
+++ b/source/blender/editors/space_clip/tracking_ops.c
@@ -4135,14 +4135,22 @@ static void keyframe_set_flag(bContext *C, bool set)
 			MovieTrackingPlaneMarker *plane_marker = BKE_tracking_plane_marker_get_exact(plane_track, framenr);
 			if (plane_marker) {
 				if (set) {
-					plane_marker->flag &= ~PLANE_MARKER_TRACKED;
+					if (plane_marker->flag & PLANE_MARKER_TRACKED) {
+						plane_marker->flag &= ~PLANE_MARKER_TRACKED;
+						BKE_tracking_track_plane_from_existing_motion(plane_track, plane_marker->framenr);
+					}
 				}
 				else {
-					plane_marker->flag |= PLANE_MARKER_TRACKED;
+					if ((plane_marker->flag & PLANE_MARKER_TRACKED) == 0) {
+						plane_marker->flag |= PLANE_MARKER_TRACKED;
+						BKE_tracking_retrack_plane_from_existing_motion_at_segment(plane_track, plane_marker->framenr);
+					}
 				}
 			}
 		}
 	}
+
+	WM_event_add_notifier(C, NC_MOVIECLIP | NA_EDITED, clip);
 }
 
 static int keyframe_insert_exec(bContext *C, wmOperator *UNUSED(op))