Mask tracking; planar tracking
Tracking a mask or flat surface through footage so a blur, cutout, or corner-pinned graphic stays locked to it.
See it
What it is
Mask tracking moves a mask through a shot so it keeps covering or isolating the same subject. Planar tracking solves the translation, scale, rotation, shear, and perspective of a flat patch such as a screen, wall, card, or license plate. Instead of following one corner, tools such as Mocha AE, built by Imagineer Systems and now sold by Boris FX, follow the texture across the whole plane.
Reach for mask tracking when a grade, blur, or cutout must follow something. Reach for a planar track when artwork needs to lock to a surface that turns in perspective, especially for screen replacements and sign changes. The solved track can drive a Corner Pin while a separate tracked shape supplies the matte.
Gotcha: the best tracking shape is not always the object's exact edge. A tight spline around a blank screen gives the tracker little texture; include useful detail on the same plane, such as the bezel, while excluding fingers, reflections, and anything moving independently. Check drift at the end of the shot, not just the first few frames.
Ask AI for it
Planar-track this phone in Mocha AE. Draw an X-Spline that includes the screen and textured bezel but excludes fingers and moving reflections, then track Translation, Scale, Rotation, Shear, and Perspective forward and backward from the clearest frame. Correct any drift with AdjustTrack. Export the solve as After Effects Corner Pin data for the replacement screen, and export a separate feathered mask for the visible display area so the graphic stays inside the glass.