Your first trace

Add the effect

1. On the Edit page, drag Ball Tracer from Effects Library → OpenFX → Ball Tracer onto the clip.
2. Open the Inspector. The top row, Status, reads No tracking yet.

Every button reports back on the Status row. When something needs your attention, a message box gives the longer explanation. Below it, the groups run 1. Range to 5. Look in the order you use them.

Mark the shot

Resolve does not tell a plug-in where your clip is cut, so you mark the shot yourself. Cover the shot, not the whole clip. A shorter range is quicker, and it keeps a practice swing out of the trace.

1. Park the playhead on the first frame of the shot and press Set Start to Playhead.
2. Park on the last frame and press Set End to Playhead.

Tell it about the camera

The trace has to know how the camera moved before it can tell the ball from the background.

• Tripod, or a shot you have already stabilised: tick Camera Is Locked Off. Trace Ball then skips the camera step. Leave it off for any shot that pans, tilts or zooms.
• A moving camera: there is nothing to do yet. If nothing is tracked when you press Trace Ball, it tracks the camera first and then carries on. To do it as its own step, press Track Camera in 2. Camera & Boxes and wait for Camera tracked.

If the automatic camera track cannot hold a shot, the two tracker boxes are the manual way. Drag Tracker A onto something near the ground that stays in frame, and Tracker B onto the background, well away from A. Then press <> Track Both Ways.

Mark the ball at impact

1. Park the playhead on the frame the club meets the ball.
2. Find the amber ring waiting at the centre of the frame. It is the Ball At Impact marker.
3. Drag it onto the ball, where the ball is still large and sharp.

This step is optional, and it is the most useful one. A flight that does not come back to this point is thrown out, so the tracer cannot settle on a bush or a bird.

Trace the ball

1. Stay on the impact frame and press Trace Ball. The frame you are on becomes the Impact Frame.
2. Status reads Tracing... while it works. It walks the shot twice, so give it a moment.
3. When it succeeds, Status reads Traced N frames. with your frame count, and the message adds The flight was checked against the ball you marked at impact.

If you have already moved a path handle by hand, the first press shows Press Trace again to replace. Press it again to let the trace replace your handles.

Check the trace

• Turn on Show Detections and scrub through the shot. It draws what the ball finder found, so you can tell the ball from a bird.
• The ball leaves the picture before it comes down: drag the Landing marker, the amber ring with a bar, to where the ball lands. Then trace again.
• The camera is tilted, high or low: move Horizon to the camera's eye line. It changes only where the landing is found.
• No ball found: see Troubleshooting, which lists each reason the message gives.

Shape the path

Points sets how many handles shape the path: 3 by default, from 2 to 6. The first is Close, the last is Far, and the ones between are Mid 1 onwards. After a trace they sit on the flight.

• Drag a handle in the viewer to move it.
• Click a handle, then use the arrow keys: each press moves it one screen pixel. Click empty picture to give the arrow keys back to Resolve.
• The two markers sit on top of the first and last handles and take the click. Untick Show Markers to grab the handle underneath. Their values are kept.
• Untick Show Tracker Boxes to clear the boxes out of the way.
• After Track Camera, you can pin the trail's ends to the scene: click a track point, then press Use as Close or Use as Far.

Time the draw-on

With Follow Ball on, which is the default, the trail draws on as the ball flies. Reveal Curve sets the pace. Ball Flight, the default, follows the traced flight. Hang and Settle, Ease Out, Linear, Burst and Fade and Snap and Drop are fixed shapes.

To set the timing from the playhead, park on a frame and press a button:

• Reveal sets the frame the trail starts to draw.
• Middle sets the frame the trail reaches the middle of the path.
• Landing sets the frame the draw-on finishes.

These three buttons work only with Follow Ball on and a curve other than Manual.

To animate it by hand, set Reveal Curve to Manual, or turn Follow Ball off. Then keyframe the Reveal slider in 4. Path. Keyframes on that slider are ignored while Follow Ball is driving it.

Style the trail

5. Look starts as one flat red line, 50 pixels wide at the close end and thinning toward the far end. The rows you reach for most:

• Colour and Width, for the close end.
• Gradient, to shift toward Colour Far along the trail.
• Taper, which gives the trail depth.
• Head Size, a dot on the leading end. It starts at 0, off.
• Shadow Opacity, a straight streak on the ground beneath the flight.
• Transparent, to output the trail on its own for compositing.

Every control lists every Look row with its default.

Finishing touches

AutoZoom

AutoZoom pushes the picture in on the ball as it lands. It starts off: AutoZoom Amount is 0.

• Set AutoZoom Amount. 30 makes the picture about a third bigger, 100 doubles it. Past about 150 the picture starts to look soft.
• It zooms toward the Far handle and is fully in as the traced ball lands. On a path you never traced, it uses End Frame instead.
• Zoom In Over sets how many frames the move takes, 12 by default. To choose when it is fully in, park there and press Arrive on Playhead.
• AutoZoom On turns the move off without losing your settings.

Holdout

To hide the trail behind a tree, use the Fusion page. There the Ball Tracer node has a second input, Holdout. Wire a mask into it, such as a Polygon or a keyer, and the trail disappears inside the mask. Holdout Amount sets how much it hides, and Invert Holdout hides it outside the mask instead.

Stop a pass, and carry on

• Press Esc to stop a pass. Press the same button again to carry on from where it stopped. Nothing is lost.
• A pass that runs short of graphics memory pauses on its own with Paused at N of M. and carries on when Resolve gives memory back. See Troubleshooting if it stops instead.
• Reset Tracking throws the stored track away. It asks for a second press first: Press Reset again to confirm.