At editor-time (ie, while using the editor and NOT in a PIE session), the Animation Blueprint's ability to read updated values appears to depend on what component of an Actor is currently selected, which is quite unexpected and confusing. If the root of the Blueprint is selected, updates work just fine. But if any other ActorComponent is selected then updates will not be made to the AnimationBlueprint. For a UProperty that is defined on an ActorComponent, the Animation Blueprint will only be able to read changing values while the root of the Actor is selected. If instead, the ActorComponent is selected, the Animation Blueprint will read stale data and thus will not appear to update.

Steps to Reproduce

See Attachment for repro project and video example of behavior.

  1. Create an Actor with a SkeletalMeshComponent and an ActorComponent that includes a UProperty, eg a float named "MyComponentValue"
  2.  Create an Animation Blueprint that, in its EventGraph's BlueprintUpdateAnimation event reads in the current state of the Actor's ActorComponent's UProperty and uses that value to update the animation. For example, having a float that drives the animation's current time.
  3.  Create a Blueprint that extends the Actor from step #1. Then assign a SkeletalMesh asset to its SkeletalMeshComponent and tell it to use the Animation Blueprint from step #2.
  4.  Place the Actor in a level.
  5.  Select the placed Actor.
  6.  Make sure that in the Details panel, the root of the Blueprint is selected, eg "MyCharacter_BP_(self)"
  7.  Change the ActorComponent's UProperty value. Notice that the animation changes as expected.
  8.  Now, in the Details panel, select the ActorComponent directly.
  9.  Change the ActorComponent's UProperty value. Notice that the animation DOES NOT change.




Skeletal mesh updates, based on Animation Blueprint having updated state


Skeletal mesh does not update. This is because the Animation Blueprint is not able to read the updated values.

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Won't Fix
ComponentUE - Gameplay - Components
Affects Versions4.244.25
CreatedApr 14, 2020
ResolvedJul 19, 2022
UpdatedJul 19, 2022