Best way to build a 4 by 4 by 4 LED cube (which would therefore include a 3 x 3 x 3) is to use a MAX7219 module. 
Vastly simpler and more reliable code.
Best way to build a 4 by 4 by 4 LED cube (which would therefore include a 3 x 3 x 3) is to use a MAX7219 module.
Vastly simpler and more reliable code.