When discussing ways to process lighting in a game, there are two main ways we can do so, known as Forward Rendering and Deferred Rendering. Both handle lighting in a different order, with different techniques, requirements, pros, and cons. Forward Rendering is usually recommended for performance, while Deferred Rendering is usually recommended for quality. The latter is used by the High Definition Render Pipeline of Unity, the renderer used for high-quality graphics in high-end devices.

At the time of writing this book, Unity is developing a performant version for URP. Also, in Unity, the Forward Renderer comes with two modes: Multi-Pass Forward, which is used in the Built-In Renderer (the old Unity Renderer), and Single Pass Forward, which is used in URP. Again, both have their pros and cons.

Choosing between them depends on the kind of game you are creating and the platform you need to run the game on. Your chosen option will change a lot due to the...