Can anyone link to / explain Unity's game loop?

Questions & Answers
1

Hopefully this is an easy enough question, but as a programmer I’m always wondering what Unity is actually doing behind the scenes. While reading through the API references, and just by trial-and-error, I’d guess the loop goes something like this:

  • Instantiate new objects
  • Call Update on all objects/components
  • Do Physics (I’m sure there are a ton of substeps, like Fixed Updates and collision events, but I don’t have a clue how they are integrated)
  • Destroy requested objects
  • Render everything according to scene graph (like physics, I have no clue what the internals of this are)
  • Call OnGUI on all objects/components
  • Flip screen buffer, loop.

Thanks for any insight you guys can give me on this!

2

Sure it looks like this:

22245-overview.png
22245-overview.png798×561 73.1 KB

Destroyed objects happen at the very end of all of that (unless of course you use DestroyImmediate).

Full article (which is about where the coroutines run): unitygems.com - unitygems Resources and Information.