[Solved] StackOverflowException when using Off-Mesh Link

General
1
  • A* version: 5.3.7
  • Unity version: 2022.3.45f1

Hello. I started using this package not long ago. It’s great, and I’ve had no issues until now. I’ve been using custom off-mesh links, with no problems, but I recently added a new custom off-mesh link script, and when the agent reaches the link, Unity crashes instantly, and I get a StackOverflowException in the logs.

StackOverflowException: The requested operation caused a stack overflow.
  at Unity.Properties.PropertyVisitor.Unity.Properties.IPropertyBagVisitor.Visit[TContainer] (Unity.Properties.IPropertyBag`1[TContainer] properties, TContainer& container) <0x19ad2073700 + 0x00048> in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyBag`1[TContainer].Unity.Properties.IPropertyBag<TContainer>.Accept (Unity.Properties.IPropertyBagVisitor visitor, TContainer& container) [0x00001] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyBag.AcceptWithSpecializedVisitor[TContainer] (Unity.Properties.IPropertyBag`1[TContainer] properties, Unity.Properties.IPropertyBagVisitor visitor, TContainer& container) [0x000b4] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyContainer.TryAccept[TContainer] (Unity.Properties.IPropertyBagVisitor visitor, TContainer& container, Unity.Properties.VisitReturnCode& returnCode, Unity.Properties.VisitParameters parameters) [0x00103] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyContainer.TryAccept[TContainer] (Unity.Properties.IPropertyBagVisitor visitor, TContainer& container, Unity.Properties.VisitParameters parameters) [0x00001] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyVisitor.VisitProperty[TContainer,TValue] (Unity.Properties.Property`2[TContainer,TValue] property, TContainer& container, TValue& value) [0x00001] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyVisitor.ContinueVisitation[TContainer,TValue] (Unity.Properties.Property`2[TContainer,TValue] property, TContainer& container, TValue& value) [0x00086] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyVisitor.ContinueVisitationWithoutAdapters[TContainer,TValue] (Unity.Properties.Property`2[TContainer,TValue] property, Unity.Properties.Internal.ReadOnlyAdapterCollection+Enumerator enumerator, TContainer& container, TValue& value) [0x00001] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyVisitor.ContinueVisitation[TContainer,TValue] (Unity.Properties.Property`2[TContainer,TValue] property, Unity.Properties.Internal.ReadOnlyAdapterCollection+Enumerator enumerator, TContainer& container, TValue& value) [0x0011a] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.PropertyVisitor.Unity.Properties.IPropertyVisitor.Visit[TContainer,TValue] (Unity.Properties.Property`2[TContainer,TValue] property, TContainer& container) [0x00051] in <c6cf1933b94a4407b76866cfe9f46dc2>:0 
  at Unity.Properties.Property`2[TContainer,TValue].Accept (Unity.Properties.IPropertyVisitor visitor, TContainer& container) [0x00000] in <c6cf1933b94a4407b76866cfe9f46dc2>:0
This goes on for a while...

I’m implementing IOffMeshLinkHandler and IOffMeshLinkStateMachine with a FollowerEntity, not a NodeLink2. It works completely fine with one of my custom scripts, but crashes with the other.

Code for the working script:

IOffMeshLinkStateMachine IOffMeshLinkHandler.GetOffMeshLinkStateMachine(AgentOffMeshLinkTraversalContext context)
{
    Debug.Log(context.link.link.gameObject.name);
    context.transform.Position = context.link.link.component.transform.position;
    context.transform.Rotation = context.link.link.component.transform.rotation;
    PlayAnim(context.link.link.gameObject.GetComponent<OffMeshLink_Component>().TraverseType);

    return this;
}

IEnumerable IOffMeshLinkStateMachine.OnTraverseOffMeshLink(Pathfinding.ECS.AgentOffMeshLinkTraversalContext context)
{
    yield return new WaitForEndOfFrame();
    float t = animator.GetCurrentAnimatorStateInfo(0).length;
    float elapsed = 0;

    while (elapsed < t)
    {
        elapsed += Time.deltaTime;
        yield return null;
    }

    yield return null;
}

void IOffMeshLinkStateMachine.OnFinishTraversingOffMeshLink(Pathfinding.ECS.AgentOffMeshLinkTraversalContext context)
{
    context.transform.Position = context.link.link.component.GetComponent<NodeLink2>().end.position;

    animator.CrossFade("Run", 0, 0, 0);
}

Code for the one that crashes:

    IOffMeshLinkStateMachine IOffMeshLinkHandler.GetOffMeshLinkStateMachine(AgentOffMeshLinkTraversalContext context)
    {

        return this;
    }

    IEnumerable IOffMeshLinkStateMachine.OnTraverseOffMeshLink(Pathfinding.ECS.AgentOffMeshLinkTraversalContext context)
    {

        yield return null;
    }

    void IOffMeshLinkStateMachine.OnFinishTraversingOffMeshLink(Pathfinding.ECS.AgentOffMeshLinkTraversalContext context)
    {

    }

I know it’s empty, but posted it anyway for clarity’s sake.

Even when I put a Debug.Log where it begins, I get nothing in the crash logs.

2

Not sure why I didn’t try this before, but I put the traversal logic in a whole new script, and it works fine, and doesn’t crash. It must have been something in my script causing the overflow. Not sure what it could be though. Ah well, problem solved.

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