Menger sponge diagonal cut

Hi,

I have little bit problem with fractal. It is about Menger sponge. I need cut it with plane (plane can be diagonal) and split sponge to left side and right side. Is there any way to perform? I want cubes with smooth edges at the cut.

Here is image of my graph and code

.

function menger(n)
if nargin < 1
        n = 2;
end
M = 0;
for k=1:n
    A = zeros([3^k, 3^k, 3^k]);
    A(:,:,1:3^(k-1)) = [M,      M,        M;
                        M, ones(size(M)), M;
                        M,      M,        M];
                    
    A(:,:,3^(k-1)+1:2*3^(k-1)) = ...
        [M,             ones(size(M)), M;
         ones(size(M)), ones(size(M)), ones(size(M));
         M,             ones(size(M)), M];
     
    A(:,:,2*3^(k-1)+1:3^k) = [M,        M,      M;
                              M, ones(size(M)), M;
                              M,        M,      M];
    M=A;
end
hold on;
axis equal;
d = 1;
for i = 1:3^n
    for j = 1:3^n
        for k = 1:3^n
            if M(i,j,k) == 0
                cube(i,j,k,d,n)
            end
        end
    end
end
view(3);
xlabel("X"),ylabel("Y"),zlabel("Z");
hold off;