1.3.9 While-loop tutorial

Usually people who have never programmed have great difficulties understanding how simple while-loops work and how they should be used. When you get into nested loops, the problem is even worse.

Sometimes even people who have programmed a bit with some language get confused with POV-Ray's while-loops. This usually happens when they have only used a for-loop which in itself has an index variable (which is often even incremented automatically).