I'm trying to create an AR app which uses AR Foundation face tracking. Unfortunately, face tracking seems to be supported on the front camera (selfie) only (TrueDepth, Lidar etc).
I found it that it also can track faces on a photo or screen (which is a flat picture). So, in theory, it still should be possible to use a back camera for face tracking. Is there way to workaround the front-camera-only restriction? I understand that it may be bad in terms of performance and quality, but I'd like to check how bad it is (if it's possible).
In theory, a possible workaround would be to extract frames captured by the rear camera and use something like OpenCV for Unity to analyze the images and detect faces.