use <modify.scad>;

module offset_by(x=0,y=0,z=0) {
    for(i=[0:1:$children-1]) {
        translate(i*[x,y,z]) children(i);
    }
}

module inner() {
    remove() cube(5);
}
mirror([1,0,0])
offset_by(y=15) {
    construct() {
        remove() cube(10);
    }
    
    construct() {
        cube(10);
    }

    construct() {
        cube(10);
        remove() cube(5);
    }
    construct() {
        add() cube(10);
        remove() cube(5);
    }
    construct() {
        add() cube(10);
        inner();
    }
    
    construct() {
        add() cube(10);
        remove() construct() {
            add() sphere(7); 
            remove() cube(5);
        }
    }
}