While-loop tutorial

## 9.7 While-loop tutorial

While-loops in POV-Ray are so often misunderstood and misused that I decided to write a whole page about them. 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).