multiple Scenes vs 1 scene and multiple panels vs 1 scene vs multiple canvases?

As usual many different factors go into a decision like this: how quickly the user changes these scenes / panels / modes, how much data has to be reconstructed if you leave one and come back to it, etc.

As far as memory used, how you organize it isn’t going to matter as much as how much texture and audio you put into it, and audio can be streamed. That’s the big users of runtime memory in mobile.

Same goes for bundle size: it’s almost always textures and audio that blow you out.

I personally LOVE additive scenes, couldn’t do without them. I use them to composite game scenes, plus I also use them for popup windows. I love additive scenes so much I have a standard blurb encouraging them!

Additive scene loading is one possible solution:

A multi-scene loader thingy:

My typical Scene Loader:

Other notes on additive scene loading:

Timing of scene loading:

Also, if something exists only in one scene, DO NOT MAKE A PREFAB out of it. It’s a waste of time and needlessly splits your work between two files, the prefab and the scene, leading to many possible errors and edge cases.

Two similar examples of checking if everything is ready to go: