Tracking has become an important tool, not only for effects work, but also for advanced color grading, as creators desire more control over the look of a scene. Imagineer Systems has been on the forefront of advancements in tracking software—they recently were awarded an Academy Award® for their planar tracker mocha—and I had the opportunity to try out their latest release, mocha Pro v3.1. (Learn more about planar versus point trackers in last issue’s Video Assist column.)
Opening up the application, I found the interface well set up for quick access to the tools needed to work on the scene. The viewer shows the clip you’re working on, and a toolbar at the top presents most of the tools needed to create and adjust the splines (2D shapes) used for tracking.
The tools and viewer are complemented with several quick keys that allow you to turn on and off various overlays and to change tools. I liked that some of the quick keys are spring-loaded: When pressed, the current tool changes, but then reverts to the original one when the quick key is released. This demonstrates one of mocha’s many features that’s geared to increasing the efficiency of the workflow.
Another example is the use of shape layers. If you need several tracking shapes, the software allows you to keep them separated into layers. This helps keep things organized when you’re working on complicated scenes. Layers are also used to establish the priority of shapes (more on that later) and can be grouped so the group is adjusted as a whole.
The timeline controls for moving through the clip and setting the range of the clip you want to work on was easy to use. I also could add keyframes right to the timeline rather than jumping into a timeline edit.
To the right of the timeline controls is a unique "überkey." By turning it on, I could make adjustments to all of the keyframes at the same time. So, if I needed to tweak a shape once I got farther into the analysis, I didn’t have to go back to the beginning of the track.
First, a little bit about starting the process in mocha. To begin tracking a shape, you need to identify the plane that it’s on. An obvious plane is a wall or floor, but planes also can be less obvious objects like a car door or the back of someone’s head.