hi there,
i am new to unity so i still have basic questions … ^^
if i create a texture with black areas, they can apear transparent on an object.
my question, how can i create ingame black / transparent areas
thank you !
Well you can use programs like Paint.NET to create transparent areas.
Once thats done you save it as a .PNG and import it to your game.
Hope this helped! 
to create ingame transparency,
first i created an object with a transparent cutout shader
after that, i get the texture form the object ( converted it to texture2d)
an set my desired part (ingame) to Color.clear
in fact really easy if you know how …