Learn how to get better results when using motion tracking in your editing. This tutorial explains how to improve track results using mocha, these tips will help you get better results with CoreMelt SliceX TrackX / SliceX / DriveX, Mocha AE and Mocha Pro.
How to get better results when tracking.
All tracking in Coremelt products uses the Mocha tracker, a planar engine to track objects in a shot. A plane is a 2d surface like this book. As it moves around within a shot it can be tracked and used to mask an effect or replace a screen
Where do you draw the track shape? Well the planar area you're trying to track doesn't need to be flat but it should move together like a rigid 2D surface does. Therefore you can still track the side of a car or someone's face, because even though it's bumpy, it looks roughly like a flat surface.
To get good results the track shapes you draw need to enclose a rigid area that moves like a flat surface. You cant track someone’s entire head because the whole head is not a single flat surface - it's multiple flat surface and we can only track one at a time.
What are the different tracking styles in track x?
In TrackX Track Layer tracks perspective surfaces you want to replace , while Simple Tracker doesn't track perspective. If you want to add a clip that faces the camera, next to a moving plane, use simple tracker . If you want to do a screen replacement, use Track Layer.
How do you track small objects?
Often, an object will start small in the distance and then get larger as it gets closer to the camera. In these cases you should start at the end of the video, where the subject is closer to the camera, then track backwards to give the track more detail to work with.
If an object stays small throughout, you might have to draw a bigger shape around that point, and track a slightly larger area. After you can change the size of the tracked area, but the already tracked movement will be saved.
How do you track objects that leave the frame?
If part of an object leaves the frame in general the track will still be good. However if it leaves the frame completely and the track fails, you may need to throw away the bad tracking data, and keyframe manually.
How do you track a whole person accurately?
If different parts of a person's body move in different ways, you'll need to track each rigid flat surface the separate shape. For example, you'll need a separate mask for the upper arm, the lower arm, the torso and so forth.
Small tiles, windows in buildings and other repeating elements can sometimes be hard to track. because they are a regular pattern, the tracker can confuse one window for another causing the track to Jump Around Where possible track a large area including a distinct element.
Moving elements like water grass or trees that wave in the wind are also difficult to track. If your shot contains any of these elements, make sure that your track shape avoids these continuously moving areas
In all these cases if you can't track an item directly, you can often track something nearby and offset the track.
We have many more tutorials on our Vimeo channels so please take a look there for help and check out our support system on Coremelt.com if you can't find what you looking for. Thanks and happy tracking!