You beat me to it!
I just saw this on a test level and its extremely noticeable and I haven’t seen it that bad before as far as I can remember. Something in Temporal AA must have changed and I think someone from Epic responded to Koola a couple pages back regarding a change in the Temporal AA. My guess is its that if that got updated in 4.9
I found an issue where a custom widget is not showing on the UI (ordering issue maybe?). I posted an AnswerHub link about this here… [4.9.0] - UMG Widget No Longer Visible - UE4 AnswerHub
I have noticed also the AI in the game I’m working on has been affected but I have yet to dive through and confirm if something maybe got disconnected in Blueprints or similar after upgrading (this has happened plenty in the past for an unknown cause). I also don’t want to rule out that it could be my error quite yet however this did work before the upgrade.
Another thing is that an old issue I posted about a year ago still seems to be present but I am not sure and don’t want to pre-emptively assume. There was a dynamic sky from the Marketplace that was added to a level and then removed after it had serious issues yet the level where it was evaluated on still retained some form of reference to it after it was no longer there (from what I can see). I’m guessing this because it also used a custom Directional Light (which was still present) and when that was set to moveable, all 32GB of my memory was eaten up (?!?!) and the bug showed up to say hey and provide some early morning entertainment of trying to diagnose the issue
When I finally deleted that light, the memory went away and the perf came back. Even if that Directional Light was being used by this custom Marketplace component, once that component was deleted, there should have been no issue with having a standalone light but something underneath the covers still had some ties to the deleted component and even though it was deleted from the Scene Outliner, there was still an actor present on some low level. I originally noticed the issue about over a year ago and would see my level show the Save Asterisk on the tab indicating to the user that an update happened and they needed to save the file after editing an asset that had no association to the level in question whatsoever (after being previously added then removed). I haven’t noticed this happening presently but seeing what I saw this morning leads me to believe this is still a major issue with the engine and has me frightened that levels could potentially get corrupt and/or unfortunately waste time for myself or other developers trying to debug rogue issues with a case like mine today where having the leftover Directional Light, completely nerfed my memory because something of the old component was still left over. Quite honestly I hope that is not the case and hoping its not that bad but I spent a fair amount of time to finally figure out it was a Directional Light all along (BTW the folder for the custom Marketplace content is still in this project today and will be getting removed entirely from source control later today and its possible after deleting this, the reference would be broken and/or simply go away from the level it was previously used in). Also as a note, I did go ahead and test out a Directional Light on another level and it didn’t do anything negative when switching from Stationary to Moveable. Only the one that was previously used on the other level that had that Marketplace Component, did it show some serious demons.
BTW, please put that fix for the Parent variable defaults in the first hotfix, this is going to cause a couple headaches in the meantime. Thanks and much appreciated!
Another thing I noticed is for some reason, PreLogin(…) in AGameMode is not being called (but have yet to test quite yet). I have a bunch of testing to do shortly so I hope to find out more… Going to stay positive