Procedural mesh vision cone
Vision cone created with a procedural mesh. Can be used for enemy line of sight, cameras etc. Made by Ben Redahan.
Get the project from Ben's Github:
This implementation is fairly rough, but it's a good starting point and it showcases an effect that's very useful for a lot of things. And best of all there's not much code here at all so it's easy to reverse engineer and extend.
Here's an article which describes how such a technique can be optimized:
Here's the Reddit thread where I initially discovered the project. People there have some tips for improvements to be made as well: