[Scene Graph] Editor Crash: Connecting Entity in Custom Verse Component (Re-submission)

General Issues and Bug Reporting
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Summary

After copying nested entities, the UEFN editor is prone to crashing. Specifically, crashes are observed in two scenarios

  • when attempting to connect an entity to a component member via the Details panel
  • when renaming an entity.
    If a crash occurs once, repeating the same process will consistently lead to crash.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Verse

Steps to Reproduce

  1. Create a nested entity structure in the editor. For example:

    - parent
  - group1
    - child1
    - child2

  2. Perform operations involving duplication of these nested entities. This might include:

    • Duplicating an entire group (e.g., group1 to create group2).
    • Adding new child entities to a duplicated group.
      The structure might then look something like this:
    - parent
  - group1
    - child1
    - child2
  - group2 (created by duplicating group1, possibly with further modifications)
    - child1 (copy)
    - child2 (copy)
    - child3 (newly added or also part of a more complex duplication)
  (...)

  3. After these duplication and modification operations, certain entities (typically the copied groups or their children, like group2 or its children) seem to become unstable or “prone to crash” when interacted with in specific ways.

  4. The editor crash can then be triggered in one of the following ways:

    • a. Renaming: Attempt to rename one of the potentially unstable entities (e.g., group2 or one of its child entities).
    • b. Linking to Component:
      1. Add the custom animation_sequence_holder_component (Verse code provided below) to an entity. (This component is similar in concept to the example found in the Epic Games documentation: Scene Graph - Editor crashes on selecting entity in details pannel).
      2. In the Details panel for this component, add an element to the KeyframeSegments array.
      3. Attempt to link one of the (now unstable) entities from step 2 to the TargetEntity property of this new keyframe_segment.

    Verse Code for animation_sequence_holder_component:

    # animation_sequence_holder_component.verse
using { /Verse.org }
using { /Verse.org/Native }
using { /Verse.org/SceneGraph }
using { /Verse.org/Simulation }
using { /Verse.org/SceneGraph/KeyframedMovement }

animation_sequence_holder_component<public> := class<final_super>(component):

    @editable
    var AnimationKey<public>:string = "Default"

    @editable
    var KeyframeSegments<public>:[]keyframe_segment = array{}

    OnBeginSimulation<override>():void =
        (super:)OnBeginSimulation()

    GetKeyframeSegements<public>()<transacts>:[]keyframe_segment =
        KeyframeSegments

keyframe_segment<public> := class<concrete>:
    @editable
    TargetEntity:?entity = false

    @editable
    AnimationDuration:float = 2.0

    @editable
    EasingFunction:?easing_function = false

    @editable
    AfterPauseSeconds:?float = false

  5. Once the editor has crashed due to either method in step 4, attempting the same action (renaming the same entity or trying to link the same entity to the component) will consistently cause the editor to crash again.

Expected Result

Renaming or linking entity as intended.

Observed Result

Editor crashes without any error display.

Platform(s)

UEFN editor

Video

Additional Notes

Video includes the reproduction.

I previously reported a bug with the same content Scene Graph - Editor crashes on selecting entity in details pannel. According to Staff Flak’s guidance, I re-report it as a new post without editing the content.

2

Logs.zip (20.1 MB)
Logs file for the simple reproduction video in post.

3

Verse component I use is similar in concept to the example found in the Scene Graph example documentation: