After Effects Mask Tracking Not Working or Drifting Fix

In this tutorial, you'll learn about After Effects Mask Tracking Not Working or Drifting Fix. We cover key concepts, practical examples, and best practices to help you understand and apply this topic effectively.

The Problem

You use the Mask Tracker in After Effects but the mask does not follow the subject, drifts off after a few frames, or the tracking points are not detected.

Quick Fix

Step 1: Use a clean reference frame for tracking

Start on a clear frame.

Wrong — starting on a blurry frame:

Start frame: motion blur → tracker cannot lock onto features

Right — start on a sharp frame:

Move to a frame where the subject is in focus and high contrast
Create the mask on this frame
Click 'Track Mask' (or 'Track Selected Mask')

Expected output: Tracker starts with good reference features.

Step 2: Adjust tracking options for better results

Default settings may not work.

Wrong — default tracking with no adjustments:

Track forward → mask drifts after 10 frames

Right — optimize tracking:

Tracker panel → Advanced Settings
Accuracy: 100% (for detailed tracking)
Use 'Adaptive Feature' for changing subjects
Use 'Apply to Mask Path' for the correct mode

Expected output: Mask tracks more accurately.

Step 3: Track in sections for long clips

Split the clip for better results.

Wrong — tracking 500 frames in one pass:

Track forward → mask drifts beyond repair at frame 200

Right — track in sections:

Track 50 frames → check → correct if needed
Then track next 50 frames
Or: track backward from middle to start and end

Expected output: Consistent tracking across the clip.

Step 4: Use multiple tracking points when one fails

Combine multiple trackers.

Apply 'Mocha AE' (included with AE) for planar tracking
Or: Track two points and use them to offset the mask

Expected output: Mask stays on target even when one point fails.

Prevention

• Start tracking from a sharp, high-contrast frame
• Set accuracy to 100% for detailed tracking
• Track in short sections (50-100 frames)
• Use Mocha AE for complex planar tracking

Common Mistakes with effects mask tracking

1. Forgetting that lazy evaluation defers computation until the value is forced, causing space leaks with unevaluated thunks
2. Using return to exit a function early instead of wrapping a pure value in the monad
3. Mixing let bindings with <- bindings in do notation, producing type errors

These mistakes appear frequently in real-world AFTER code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ