Tutorial 2: 2D Point Tracking

This tutorial teaches you how to use Nuke's Tracker node for tracking, stabilizing, and match-moving.

Introduction

Every filmmaker knows the challenges of putting together a vision. You may not have the money to build post-apocalyptic Montreal, but you might have enough to create it in post. You may have brilliant performances by your actors - but not together in the same shot. Fortunately, you can composite the best takes. Your battle sequence with 5 A-list actors, 100,000 extras and 57 elephants, comes back from the lab with scratches on the negative. You can fix it. You can. A savvy production team knows how to leverage digital technology to make it possible, and Nuke’s tracking tools are indispensable for these situations.

As you may know, tracking is the process of recording the location of features as they move through the scene. The result is stored as 2D coordinates on the image plane. Once you have the tracking data, you can use the movement to perform a variety of useful tasks, such as stabilizing the footage, applying the movement to other elements in your composite, and improving the accuracy of roto mattes.

Tracking image features.

An important aspect of the tracking process involves carefully reviewing your footage before you attempt to track. Play through your sequences several times and look at the direction of movement for the features you want to track. Note potential problems with motion blur, obscuring objects, or frames where the features are hidden or move off screen.

Tip:  Nuke can often compensate for problem footage, but tracking works best when you can identify distinct features throughout the length of the shot.