Thundewave, does the caster get to designate t…

Thundewave, does the caster get to designate the starting location of the 15 ft cube?

Ok, I need to know the official answer. @mikemearls when casting thunderwave, does the caster get to designate the starting location of the 15 ft cube? Is the spell’s description of “originating from them” cast from any location within or next to the cube? next to — Mike Mearls (@mikemearls) May 29, 2018