Tracker Node

The Tracker works by pattern matching: you define a small rectangle of distinctive pixels (the pattern) and a larger rectangle (the frame-by-frame search area). On each frame, Fusion looks for where the pattern sits inside the search area, records the position and moves on to the next frame.

The tracker can run several active trackers at the same time - a single one for simple tracking, four for a corner pin. Each tracker produces its own keyframeable data track.

• Effects Library: Tools > Tracking > Tracker
• Quick add: right-click in the Node Editor → Add Tool > Tracking > Tracker

• Background (orange) - the main 2D image to track. The image the patterns are extracted from.
• Foreground (green) - optional. Image to merge on top through a corner pin or match move.
• Effect Mask (blue) - optional. Limits tracking to certain areas (handy to ignore moving objects in the frame).

Sign replacement:
MediaIn (shot footage) → Tracker (Operation = Corner Pin) → MediaOut
                                    ↑
                   Text+ / Image ────┘ (FG to apply)

Stabilization:
MediaIn → Tracker (Operation = Match Move, Steady) → MediaOut
(Merge Control = BG Only)

Driving a parameter:
MediaIn → Transform (Center connected to Tracker → Tracker1 Position)
Background → Merge

Tracker list

List of active trackers. Add adds a tracker, Delete removes one. Each tracker can be renamed, disabled (suspend - keeps the data) or deleted entirely.

Tracking buttons

5 buttons: Track Backwards, Track Backwards from Current, Stop, Track Forwards from Current, Track Forwards. They start / stop the analysis.

Frames per Path Point

How often keyframes are recorded. 1 = one keyframe per frame (precise). 2 = one keyframe every other frame (smoother, faster for slow motion).

Adaptive Mode

How the pattern behaves during tracking:

• None: fixed pattern. The strictest, least tolerant of variations.
• Every Frame: the pattern is reacquired on every frame. Tolerates lighting changes but drifts more easily.
• Best Match: the pattern is reacquired only when confidence is high. The ideal compromise.

Path Center

Where to place the new path: Pattern Center (standard) or Offset (follow a point offset from the pattern, useful when the real point of interest lacks the contrast to be tracked directly).

Pattern Windows

Two visual windows on the right: left = initial pattern, right = current pattern acquired during tracking. Confidence indicator: green (excellent match), yellow (uncertain), red (failure). Stop immediately if it turns red and fix it.

None

No transformation. Pure tracking - the data is used to drive other nodes through Connect To.

Match Move

Transforms the background to stabilize the pattern (Steady) or transforms a foreground to follow the tracker data. Works with 1, 2, 3 or 4 trackers for translation / rotation / scale / perspective.

Corner Positioning

Follows 4 corners (needs 4 active trackers). Applies the transformation to a foreground to replace a rectangle in the scene (screen, sign, license plate).

Perspective Positioning

The reverse of Corner Positioning - removes the perspective distortion from the background (to get a front-on view of an element tracked by its 4 corners, e.g. flattening a screen).

Key parameters in Match Move mode

Merge Controls

BG Only (pure stabilization), FG Only, FG Over BG (final composite), BG Over FG.

Filter Method

Resampling filter: Box (fast), Linear, Cubic, Catmull-Rom (clean default), Gaussian / Mitchell (quality compromise), Lanczos / Sinc (top quality, slower).

Edge Handling

Black Edges / Wrap / Duplicate / Mirror - behavior at the edges revealed by tracking (stabilization often leaves black edges when the frame shifts).

Reference Mode

Reference frame(s) for stabilization: Select Time (single frame), Start, End, Start and End (smooths without locking the shot completely - useful to stabilize without freezing).

Pattern Rectangle (solid red)

The pattern area to track. It should sit on a distinctive feature (corner, high contrast). Resize it by dragging the edges.

Search Rectangle (dashed)

The area where Fusion looks for the pattern on the next frame. Always larger than the pattern, and sized to how fast the feature moves (big movement → large search area). Larger = slower.

Repositioning Handle

Small handle at the top left of the pattern - lets you reposition the pattern without changing its size. Shows a zoomed preview of the pattern under the cursor.

1. Add the Tracker node after MediaIn.
2. In the Trackers tab, create a pattern by placing the red box on a distinctive detail (e.g. the corner of a window, the corner of a sign).
3. Adjust the Search Rectangle (dashed) so it covers the maximum movement between two frames.
4. Go to the first frame of the sequence. Click Track Forward.
5. Watch the confidence (color of the right pattern window). Red? Stop, adjust, run it again.
6. Once tracked, go to the Operation tab and pick the mode you want (Match Move, Corner Pin, None).
7. Connect the foreground if needed, or use Connect To to drive an external parameter.

• Stabilizing shaky footage - 1 tracker → Operation Match Move, Merge BG Only, Reference Start and End = a smoothed shot that is not completely frozen.
• Sign / screen replacement - 4 trackers on the corners of a screen or sign → Operation Corner Positioning → FG = image or Text+ → the image replaces the screen and follows the perspective of the shot.
• Attaching to a face or a moving object - 1 tracker on a point of the face → connect the data to a Transform Center so a graphic (arrow, text) follows the character.
• Removing an element from shaky footage - tracker on the background → Steady → Paint or Patch to remove an object → Unsteady to bring back the original movement.
• Adding a glow that follows the eyes - tracker on each eye → Glow position linked to the tracker → a sci-fi glow that follows the gaze perfectly.
• Tracking a vehicle for a label - tracker on the car → Text+ position connected → a "135 km/h" title that follows the vehicle through the shot.

• A good pattern = contrast + distinctive + small - aim for a clear corner or intersection rather than a flat surface. A small pattern (20-30px) = fast computation.
• A well-sized search area - too large = slow + risk of locking onto the wrong pattern. Too small = the pattern gets lost with fast movement.
• Adaptive Best Match by default - a good compromise. Every Frame if the lighting changes a lot. None if the lighting is stable and the pattern ideal.
• Channel selected automatically - Fusion picks R, G or B depending on how clear the pattern is. Force a channel manually if the tracking fails (G often gives a better result than combined RGB).
• Suspend a tracker instead of deleting it - it keeps the data already acquired. Useful if you want to combine several trackers for different sections of the shot.
• Offset tracking - if the real point has no contrast, track a distinctive point nearby and use the Offset to aim at the real point.
• Prepare the shot before tracking - light denoise, boosted contrast on the Tracker input only (add a Color Corrector right before it). Better lock.
• For complex shots (perspective + rotation + occlusions), prefer the Planar Tracker - more powerful on flat surfaces.