AnimatorExtensions

Extension methods for UnityEngine.Animator that provide callback-based subscriptions to OnAnimatorIK and OnAnimatorMove messages. Uses a hidden proxy MonoBehaviour (AnimatorListener) that is auto-attached to the Animator's GameObject on first subscription.

Definition

Namespace: Paragon Assembly: Paragon.dll

public static class AnimatorExtensions

Remarks

Unity's OnAnimatorIK and OnAnimatorMove messages are only sent to MonoBehaviour scripts on the same GameObject as the Animator. This extension class solves the problem of subscribing to these messages from external scripts that do not live on the Animator's GameObject.

It works by lazily attaching a private AnimatorListener component (hidden in the Inspector via HideFlags.HideInInspector) to the Animator's GameObject. The listener receives the Unity messages and forwards them via C# event Action delegates.

Listener Lifecycle

• First Add*Listener call: If no AnimatorListener exists on the GameObject, one is added automatically.

• Subsequent calls: Reuses the existing AnimatorListener.

• Remove*Listener calls: Unsubscribes the callback. The AnimatorListener component remains on the GameObject (not removed).

Quick Lookup

Goal	Method
Subscribe to IK pass	animator.AddIKListener(callback)
Unsubscribe from IK pass	animator.RemoveIKListener(callback)
Subscribe to root motion	animator.AddMoveListener(callback)
Unsubscribe from root motion	animator.RemoveMoveListener(callback)

Methods

AddIKListener

Subscribes a callback to be invoked during OnAnimatorIK. Adds an AnimatorListener component if one does not already exist.

public static void AddIKListener(this Animator animator, Action onAnimatorIKCallback)

Parameter	Type	Description
animator	Animator	The Animator to listen to
onAnimatorIKCallback	Action	Callback invoked each IK pass

RemoveIKListener

Unsubscribes a callback from OnAnimatorIK. No-op if no AnimatorListener exists on the GameObject.

public static void RemoveIKListener(this Animator animator, Action onAnimatorIKCallback)

Parameter	Type	Description
animator	Animator	The Animator to stop listening to
onAnimatorIKCallback	Action	Callback to remove

AddMoveListener

Subscribes a callback to be invoked during OnAnimatorMove. Adds an AnimatorListener component if one does not already exist.

public static void AddMoveListener(this Animator animator, Action onAnimatorMoveCallback)

Parameter	Type	Description
animator	Animator	The Animator to listen to
onAnimatorMoveCallback	Action	Callback invoked each move pass

OnAnimatorMove overrides root motion. When any MonoBehaviour on the GameObject implements OnAnimatorMove, Unity stops applying root motion automatically. Adding a move listener via this method has the same effect — root motion must be manually applied inside the callback.

RemoveMoveListener

Unsubscribes a callback from OnAnimatorMove. No-op if no AnimatorListener exists on the GameObject.

public static void RemoveMoveListener(this Animator animator, Action onAnimatorMoveCallback)

Parameter	Type	Description
animator	Animator	The Animator to stop listening to
onAnimatorMoveCallback	Action	Callback to remove

Common Pitfalls

AnimatorListener is never auto-removed. Calling RemoveIKListener / RemoveMoveListener unsubscribes the delegate but does not remove the AnimatorListener component. If all listeners are removed, the component remains as an inert hidden component.

IK must be enabled on the Animator layer. OnAnimatorIK is only called for layers that have IK Pass enabled in the Animator Controller. If the IK listener callback is never invoked, check the layer settings.

Examples

Subscribing to IK from an External Script

using UnityEngine;
using Paragon;

public class IKController : MonoBehaviour
{
    [SerializeField] private Animator animator;
    [SerializeField] private Transform lookTarget;

    void OnEnable()
    {
        animator.AddIKListener(OnAnimatorIK);
    }

    void OnDisable()
    {
        animator.RemoveIKListener(OnAnimatorIK);
    }

    private void OnAnimatorIK()
    {
        animator.SetLookAtWeight(1f);
        animator.SetLookAtPosition(lookTarget.position);
    }
}

See Also

• Extensions — extension system overview