Hi, I want to build a 4^3 LED Cube but I have a few questions, I hope you can help me with. What exactly is the need for the transistors? From what I understand, they only allow the circuit to be completed if one of the pins sends out '1'. But this is kind of backwards thinking. Why is this necessary? Surely just sending '1' directly to the pin instead of going through a transistor would have the same effect?