Shapes and 3D effect in Affinity Photo

[Funn4Lo]

I made a simple roof design in Affinity Photo, from rectangular shapes, and then color filled.  It looks great flat, like one continuous piece.

I want to add some 3D effect, but when I do, it highlights the intersection of the rectangles. Is there a way to merge the rectangles, so to speak, so that the 3D effect follows the entire shape? 

[Ron P.]

Select both rectangles, right-click, Geometry>Add.

[Funn4Lo]

 

33 minutes ago, Ron P. said:

Select both rectangles, right-click, Geometry>Add.

Heck to the yes! That worked