Layermasks took me a while to figure out and get working correctly, and I've seen a few people asking about them on the forums, so I thought I'd add a little something to help anyone who may be struggling with them.
The question is: How do I use/create layermasks to use with, e.g., Physics.Raycast or other Physics functions? For those who don't know: a layermask allows you to specify certain layers to exclude/include in certain physics functions.
