Component to evaluate Unity Animator in-editor with the press of a button by calling Animator.Update(0f) exactly once. Useful for applying one frame of animation to an object, such as a model pose, and saving it permanently in the scene. Supports undo.

AnimatorEvaluate.cs

using System;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

[RequireComponent(typeof(Animator))]
public class AnimatorEvaluate : MonoBehaviour
{
}

#if UNITY_EDITOR
[CustomEditor(typeof(AnimatorEvaluate))]
public class AnimatorEvaluateEditor : Editor
{
    const string CallAnimatorUpdateButtonText = "Call Animator.Update(0f)";
    private GameObject _GameObject;
    private Animator _Animator;

    void OnEnable()
    {
        _GameObject = (target as Behaviour).gameObject;
        _Animator = _GameObject.GetComponent<Animator>();
    }

    private static void PerformActionOnAllDescendants(Transform xform, Action<Transform> action)
    {
        action(xform);
        foreach (Transform child in xform)
            PerformActionOnAllDescendants(child, action);
    }

    public override void OnInspectorGUI()
    {
        if (GUILayout.Button(CallAnimatorUpdateButtonText))
        {
            PerformActionOnAllDescendants(_GameObject.transform, (xform) =>
            {
                Undo.RecordObject(xform.gameObject, CallAnimatorUpdateButtonText);
            });

            _Animator.Update(0f);

            PerformActionOnAllDescendants(_GameObject.transform, (xform) =>
            {
                if (PrefabUtility.IsPartOfAnyPrefab(xform.gameObject))
                    PrefabUtility.RecordPrefabInstancePropertyModifications(xform.gameObject);
            });
        }
    }
}
#endif