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How to use Mocha Pro in After Effects: a planar track and Corner Pin screen replacement

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This guide shows how to use Mocha Pro in After Effects for the most common job: tracking a flat surface such as a phone screen and pinning new footage onto it. It covers applying the effect, drawing the layer, tracking, checking the surface and exporting the Corner Pin.

Updated · 7 min read · By Planar Track Notes

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To use Mocha Pro in After Effects, apply it from the Effects panel under Boris FX Mocha, click the Mocha launch button, draw a spline layer around the flat surface you want to track, and track forwards and backwards. Check the surface corners, save and close. Back in After Effects, click Create Track Data, set Export Option to Corner Pin, choose the target layer and click Apply Export.

Before you start

You need the plugin installed for Adobe hosts and a licence or an active trial; the download and trial steps cover both. This walkthrough uses a shot of a phone screen, but the same method works for signs, walls, laptop screens and tabletops. The surface needs some texture or edges for the tracker to follow; a perfectly blank screen gives it little to hold.

Put your shot and the replacement footage in one composition. Turn on GPU acceleration in your preferences if your card meets the Mocha Pro GPU requirements.

Track a screen and pin new footage

  1. Apply the effectSelect the footage layer, open the Effects panel, expand Boris FX Mocha and drag Mocha Pro onto the layer.
  2. Launch the interfaceIn Effect Controls, click the Mocha launch button. The full interface opens with your clip loaded.
  3. Draw the tracking layerGo to a frame where the surface is large and clear. Pick the X Spline or Bezier layer tool and click around the surface, staying inside any edges that will be covered by fingers or reflections. Right click to close the shape.
  4. Track the planeClick Track Forwards, then go back to the start frame and click Track Backwards. Watch the shape follow the surface; stop and redraw if it slips.
  5. Align the surfaceTurn on the Surface tool and drag its four corners onto the corners of the screen. Scrub through the clip to check they stay locked. Use AdjustTrack for any drift.
  6. Save and returnSave the project and close the window. The track is stored in the effect, so nothing is lost when you return to After Effects.
  7. Export the Corner PinIn Effect Controls, open Tracking Data and click Create Track Data. Set Export Option to Corner Pin (or the motion blur version), set Layer Export To to your replacement footage layer and click Apply Export.

Check the result

Play the composition. The replacement should sit on the screen through the whole shot. If a corner floats for a few frames, go back into the interface, fix it in AdjustTrack and export again; Apply Export overwrites the previous keyframes.

For fingers crossing the screen, use the same track to drive a roto mask: draw a second layer around the finger, link it to the screen track, and use the Matte output or the AI Matte Assist ML tool to cut it out.

Where to go next

The same track can drive the Remove module to erase what was on the screen, or the Insert module to render the replacement inside the plugin with motion blur. Those modules are not in the After Effects edition, as the Mocha Pro vs Mocha AE comparison shows. If you decide to buy, the Mocha Pro pricing page lists the Adobe single host options.

Try this on your own shot

The 14 day trial includes every module used here.

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Frequently asked questions

How do I open Mocha Pro inside After Effects?

Select your footage layer, open the Effects panel, find Boris FX Mocha and apply Mocha Pro. Then click the Mocha launch button in Effect Controls to open the full interface.

Why does my planar track slip?

Usually the shape includes something that moves differently from the surface, such as a reflection, a finger or the background. Redraw the layer to cover only the surface, or use AdjustTrack and the Auto Nudge tool in version 2026.5 to correct drift.

What is the difference between Corner Pin and Transform export?

Corner Pin moves four corners and so reproduces perspective, which a screen replacement needs. Transform exports position, scale and rotation only, which suits text or graphics that should not skew.

Can I track in Mocha Pro and render in Premiere Pro?

Yes. The plugin also runs in Premiere Pro, where it can export spline masks and render modules such as Insert and Remove directly in the editing timeline.

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