Asynchronous Additive Loading

Unity Engine
1

I’m attempting to know the best way to make use of Application.LoadLevelAdditiveAsync. I would like to load a new scene, but not have it be visible until I “flip a switch”. I thought perhaps setting asyncOperation.allowSceneActivation would do the trick, however, the documentation doesn’t really tell me how to use this. How do I know when the scene is loaded but not activated? The best I can tell from my own experimentation is that the asyncOperation.progress will be 0.9? Even so, how do I then activate the scene.

I separately tried making the root node of my loaded scene inactive in the editor. This almost worked, as I can see the inactive nodes being added in the scene. But then since .Find() doesn’t work on inactive nodes I don’t know how to grab them and activate them.

Perhaps I am completely missing something here?

2

I just started tinkering with AsyncOperation.allowSceneActivation as well, and I think I got one step further, but have similar findings.

As best as I can tell, the appropriate way to make use of it is with the following steps:

  • Begin the AsyncOperation. (i.e. AsyncOperation async = Application.LoadLevelAdditiveAsync)
  • set AsyncOperation.allowSceneActivation to false
  • Wait until the asyncOperation’s progress is 0.9 or larger. AsyncOperation.isDone won’t be set to true until the asyncOperation completes including activation.
  • set AsyncOperation.allowSceneActivation to true
  • yield on the AsyncOperation or wait until AsyncOperation.isDone is true

It would be good to get a confirmation that these are the appropriate steps. Either way, waiting until progress is >= 0.9 seems like an arbitrary and also undocumented process. I’d much rather have a flag that specifically says when non-activation loading is completed… or even better, an alternate means of yielding until AsyncOperation.allowSceneActivation is ready to be toggled back.

1 Like
3

After struggling for a while with allowSceneActivation, the ‘wait for >=0.9’ thing seems to work for me too. My current scene loads appear to stop at exactly 0.9 when allowSceneActivation is false.

It does seem a very ugly solution, though. Is it actually safe to do this? - Is there really no cleaner option?

4

Doesn’t work for me. My scene loads to 0.9, I put the allowSceneActivation to true, and the scene is not loaded. ;_;

5

The approach described here is pretty much exactly what I do in SECTR STREAM. It’s not super pretty, but I’ve found it to be totally robust.

6

This is the problem I have currently: