Create thick Gyroid

I want to give thickness to a Gyroid Function for Gyroid is

Gyroid=(cos(x) .* sin(y) + cos(y) .* sin(z) + cos(z) .* sin(x));
% Reverse Gyroid
R=sqrt( (-sin(x).*sin(y)+cos(x).*cos(z)).^2+(-
sin(y).*sin(z)+cos(y).*cos(x)).^2+(-sin(z).*sin(x)+cos(z).*cos(y)).^2 );

Currently I am getting two surfaces. I want to close the gaps using isocaps. current outcome

This is the output I expect but as one Isosurface def and not by using isosurface separately for both surfaces. desired outcome should be like this