menger_sponge.scad

module menger_sponge(n) {
    if (n <= 0) {
        cube(center=true);
    } else {
        for (x=[-1:1]) {
            for (y=[-1:1]) {
                for (z=[-1:1]) {
                   if (abs(x)+abs(y)+abs(z) >= 2) {
                       scale(1/3)
                       translate([x,y,z])
                       menger_sponge(n-1);
                   }
                }
            }
        }
    }
}

scale(30)
menger_sponge(3);