Feature request - option to set default camera

[svprdga]

Hi and thank you very much for creating this great scanning library.

One possible improvement that could be done is the option to choose which camera opens by default (apologies if this is already implemented, but I haven't seen any documentation on this).

In my particular case I am using this library in an app where I want the main camera to be the rear one, but the front one opens by default. This causes the user to always have to press the button to switch cameras.

Thanks.