MAPP3D is a 3D prediction app made by MeyerSound. It’s free and gives very precise predictions, but it’s user interface is of the legendary Meyer “for nerds and not very handy to work with” level. One can import DWG’s of existing halls, create prediction surfaces on the audience ear level and see what the interaction is between the loudspeakers. Alas walls cannot be set yet (like in MappXT, the 2D version of MAPP)……..
To get to know the quirks of the program, one should follow these instruction movies by Merlijn van Veen: