hot!!

Lovely. I think I saw a small glow render of yours earlier too. Like to see you do something with that.

It is very simple when you are using Distance Estimation. You only have to count how many steps you need to find fractal surface or left rendering area. Glow intensity will be higher near fractal boundary because steps for finding fractal surface will be smaller and program has to calculate more steps. On attached drawing I tried to illustrate this effect. When you have number of steps you can use this value to make pixels brighter proportional to this value. But remember. It works only when program uses not constant steps but proportional to estimated distance. This glow effect don't make rendering slower because it needs only one simple counter.