I remember watching demoscene efects and wondering “What the hell?! How they make those pixels bending into a tunel?” Back then I didn’t quite understand tunel effect. I was dreaming about different ways of bending, my head was floating into abstract concepts instead of just go back to school at do the math. In precious post I was describing roto zoom efect and when you think about it a little bit harder then it gets quite obvious. To have tunel effect you have to: 1. Scale up texture 2. Rotate texture 3. Make this scale around circle from inside to the edges of screen

Seems easy, no? Acctually I’m still strugling with it, so I promise next time I will be here with some code & examples