A track matte is an element used in Adobe After Effects or Premeirie Pro to mask out portions of a layer. The masking is calculated by either the alpha channel or luma values of the element used as a track matte. There are many benefits of using a track matte versus a regular bezier mask. Some of them are:
•By using a track matte, you are able to keep the matte layer stationary and animate only the masked layer. Whereas with bezier masks the same outcome requires having to animate postion AND mask shape parameters for the masked layer.
•Creation of highly complex mattes are far easier as you are not limited to simply shape and feather parameters as you are with bezier masks.
•Transitions are highly simplified by animating a number of objects, in any one of an infinite number of ways, within a comp and then using that entire comp as a track matte on a video or graphic layer. Trying to accomplish complex transitions with a large number of bezier masks would be time consuming and involve a large amount of keyframing.
Berikut adalah contoh Track Matte tutorial