Constant anim notify begin events when playing online

Development Character & Animation
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1

I’m reasonably certain that the issue we’re facing is this:

We make fairly heavy use of animation notifies and so the firing of them being unreliable is something of a major blocker. We are unlikely to have the option to upgrade to 5.8 in time for launch; is there a fix we can apply locally for this issue?

2

Steps to Reproduce
Create an animation blueprint

Add a montage slot

Create a gameplay ability which triggers an anim montage in that slot

In that montage put a timed notify

Simulate a networked game with multiple players

Trigger the anim montage via a locally predicted gameplay ability

Observe that notify begin fires every frame

3

Hey there,

Yes, most likely this is the same issue. The reason this happens is because of a function in the character movement component, UCharacterMovementComponent::MoveAutonomous. This function ticks the skeletal mesh animation while handling network corrections to handle when a correction happens while playing a montage. The issue is that UCharacterMovementComponent::MoveAutonomous doesn’t perform a complete update and evaluation of the anim instance which has a cascading effect to where the queue for notifies contains both start and end data on every frame.

I’ve attached a patch file that should help with the issue. Could you try it out and see if it helps? It copies UAnimInstance::ActiveAnimNotifyState before MoveAutonomous updates the anim instance, and reapplies it after the notifies have been dispatched. Between copying and re-applying, it also strips out any non-montage notifies from the anim instances’ ActiveAnimNotifyState buffer since MoveAutonomous only cares about notifies from montages.

Dustin

4

Got it,

We have an official fix in review right now, as soon as it is through review, I’ll make a patch file for you and link you to the CL as well.

Dustin

5

Hi Dustin,

Thanks for quick response. I gave it a go but I’m afraid I still seem to be seeing the event firing multiple times from the call:

OwnerMesh->ConditionallyDispatchQueuedAnimEvents();

within:

if (OwnerMesh->VisibilityBasedAnimTickOption <= EVisibilityBasedAnimTickOption::AlwaysTickPose && AnimInstance->NeedsUpdate())

which doesn’t seem to have been altered by the patch. That’s also inside a check on EnableQueuedAnimEventsOnServer which has the comment:

“Enabling this is recommended in projects using Listen Servers.” (which ours is)

6

Thank you, very much appreciated.

7

Alright, here’s a p4 patch file that you can try. This is also CL: 47265321 in mainline. Let me know if this helps you out.

8

Much appreciated. I did some quick testing with the patch applied and can confirm that Begin and End seem to only fire once per connected player.