Use the face tracker to create an effect that responds to someone's face.
When you've applied a face mesh to a face tracker, you can add a material and create a mask effect. Find out more in this tutorial.
You can add more than one face tracker to a scene, to create an effect that responds to more than one person.
If your effect has a face tracker, an instruction saying Find a face! will appear until a face is detected. You can also add custom instructions.
To insert a face tracker:
When you've selected the face tracker in the Scene tab, you can make changes to its properties in the Inspector panel:
Uncheck this box to stop the face tracker and any children from being rendered in the scene.
Choose the face in your scene that you want this face tracker to track.
You can't change the transformations for a face tracker, because it isn't an object.
Turn the points being tracked on the face into a texture.
Insert simple combinations of patches involving the face tracker into the Patch Editor.
Choose the camera or cameras on a mobile device that you want to render the face tracker and its children in.