Unity Physics Materials – what is Friction Direction 2?

When you create a Physics Material, they have three extra options at the bottom of the panel; Friction Direction 2, Dynamic Friction 2 and Static Friction 2.

Here’s a picture explaining maybe the most common use case for different frictions for different axes. Friction 2 allows you to have high friction in one axis and low friction on another, if you think about a car it will work like this: