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Tracking, stabilising and camera solves.

Tracking follows something through a shot, so what you add moves with it: a logo on a moving sign, a label on a running shoe. The same trackers steady a shaky shot, and a camera solve finds the camera itself, so 3D titles stay put in the room.

Track footage

  1. Select the footage. Its Tracking section appears in the Inspector.
  2. Press Track points, then click on the Stage on each feature to follow: a corner, a dot, a high-contrast mark. Or press Track plane and drag a box over a flat surface, such as a sign or a screen.
  3. Each tracker is listed in the section. Press its Track and choose Forward, Backward or Both.

Tracking runs in the background, so you can keep working while it goes. Trackers belong to the footage they came from.

Correct a tracker

If a tracker slips on a frame, go to that frame and drag its box back into place. Track again, and it tracks from your corrections.

Attach a layer to a tracker

  1. Track the footage first.
  2. Select the layer to attach, such as a logo.
  3. Open Transform's Add menu in the Inspector and choose Attach to, then the tracker.

The layer follows the tracker from where it is now. Its Influence sets how much it follows, from 0% to 100%, and its own Position, Rotation and Scale stay editable on top, so you can nudge the logo after it's attached. Remove takes the relation away and leaves the layer where it is.

Stabilise a shot

  1. Track a feature that should stay still.
  2. In the footage's Tracking section, press Stabilize and choose the tracker.
  3. Set Smoothing: 0% locks the shot to the tracker, and higher values keep that much of the intended camera move and remove only the shake.
  4. Set Edges to Show, to see the uncovered edges as transparent, or Scale to fill, to fill the frame with one constant scale.

Solve the camera

A camera solve finds the camera and lens that filmed a shot, from features it tracks itself, so 3D layers you add stay fixed in the scene as the camera moves.

  1. Select the footage. In its Camera solve section, press Solve camera. It runs in the background; Stop keeps the last result.
  2. Read the result. Average error is in source pixels, and a graph shows each frame's error, with a line at one pixel and ticks on weak frames. Click the graph to go to a frame, and use Previous weak frame and Next weak frame to check them.
  3. If the solve can't measure something, it says what and what to do, such as "The camera barely moves sideways, so the scene's depth could not be measured."

The lens

Focal length
Solve finds it from the footage. Fixed uses the length you enter, in millimetres. If the camera's motion doesn't reveal it, the solve asks you to set it to Fixed and solve again.
Distortion
Solve finds the lens distortion; Fixed keeps the distortion that's set, none unless you set it. Layers you add to a solved shot are distorted to match the footage.

Change the lens settings, then press Solve again.

Use the solved camera

Press Use as active camera in the Camera solve section. The composition now renders through the solved camera, and the section says so. The solve never takes over the camera on its own. Look through the solved camera in the Viewer's view menu to place 3D layers in the scene; see 3D layers and cameras.