What is cone tracing?

I’m just jotting down notes on how to do things before I actually get started trying to learn how to make my own game.

I saw this eye catching thumbnail of some very cool looking grass(which I have no idea how to make) and wanted to see how he made his lighting look so good. It even has some type of redish tint from the glare of the sun. Rolling Hills - real-time grass rendering - YouTube

So what exactly is cone tracing and how do you do it in Unity?

Cone tracing isnt something I wouldnt be concentrating on if you are just starting to make games. But if you want to learn about rendering techniques then I have linked you to a PDF that explains what cone tracing is and the maths/ concepts behind it.

Click here