Streaming world stutters due to manual GC

I have a streaming world that will stream smoothly, so the async loading and unloading is not a problem. However when unloading sectors that are getting far away from the player, even tho all objects in the sector scenes that are unloaded are destroyed, it remains in memory unless you call Resources.UnloadUnusedAssets() manually, or else it will eventually crash due to OutOfMemory.
So the only way to solve this is to call Resources.UnloadUnusedAssets().

Here's the issue, when calling UnloadUnusedAssets() that causes the game to pause for a half second, enough to cause the game to feel very interrupted.

- What is everyone who makes open streaming worlds with Unity doing about this issue?
- What do you folks who work at Unity suggest?

 

bumpy

 

Unity 2018.3 ships with an improved GC, that is spread across multiple frames to avoid frame-rate drops. Have you tried 2018.3 already?

Every bigger or open-world'ish Unity game I've played (on my Xbox) suffered from this issue. The only Unity game that ran butter smooth for me is INSIDE and it's "just a side-scroller".

PlayDead's solution to stutter free frame-rates in Unity was to buy a source license and fix the engine code, as presented in this Unite talk:

Spoiler: Unite 2016 - Tools, Tricks and Technologies for Reaching Stutter Free 60 FPS in INSIDE

Please submit a bug-report as described in this document:
https://unity3d.com/unity/qa/bug-reporting

It's important that you report these issues together with a reproduction project if you want them to get fixed. If you don't do it, it might be a long time until someone else reports them or until Unity Technologies find them.

After you submitted the bug-report, you receive a confirmation email with a bug-report Case number. You can post the Case number (number only, not the link) in this forum thread for Unity staff to pick up, in case they see it.

 

Hi I use 2018.3 Not sure how to activate that multiple frame GC.
So you mean UnloadUnusedAssets() which calls GC, is not supposed to cause stutter?

 

I was wrong, it's available in 2019.1:
https://blogs.unity3d.com/2018/11/26/feature-preview-incremental-garbage-collection/
In 2019.1, you can enable it in "Edit > Project Settings > Player" and the option is called "Use incremental GC".

I would consider it a bug. It's pretty much not applicable to use in a game (outside a loading screen), if it causes the game to stand still for a second.