AnimatorControllerLayerをコピーするやつ。Editorフォルダの下に入れること。

AnimatorUtilities.cs

#if UNITY_EDITOR
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using UnityEditor;
using UnityEditor.Animations;

namespace EsnyaFactory {
  public class AnimatorUtilities : EditorWindow
  {
    [MenuItem("EsnyaFactory/AnimatorTools")]
    static void Init()
    {
        AnimatorUtilities window = (AnimatorUtilities)EditorWindow.GetWindow(typeof(AnimatorUtilities));
        window.Show();
    }

    public enum OverrideBehavior {
      DoNothing,
      Override,
      Add,
    }

    AnimatorController sourceAnimator;
    AnimatorOverrideController sourceAnimatorOverrideController;
    AnimatorController destinationAnimator;
    Dictionary<int, bool> copyLayer = new Dictionary<int, bool>();
    Dictionary<int, bool> copyParameter = new Dictionary<int, bool>();
    OverrideBehavior overrideBehavior;


    void OnGUI()
    {
      sourceAnimator = (AnimatorController)EditorGUILayout.ObjectField("Source (Animator)", (Object)sourceAnimator, typeof(AnimatorController), false);
      sourceAnimatorOverrideController = (AnimatorOverrideController)EditorGUILayout.ObjectField("Source (Animator Override Controller)", (Object)sourceAnimator, typeof(AnimatorController), false);
      destinationAnimator = (AnimatorController)EditorGUILayout.ObjectField("Destination", (Object)destinationAnimator, typeof(AnimatorController), false);

      sourceAnimatorOverrideController.ApplyOverride();

      EditorGUILayout.BeginVertical(GUI.skin.box);
      EditorGUILayout.LabelField("Copy Layer(s)");
      if (sourceAnimator) {
        for (int i = 0; i < sourceAnimator.layers.Length; i++ ) {
          copyLayer[i] = EditorGUILayout.Toggle(sourceAnimator.layers[i].name, copyLayer.ContainsKey(i) ? copyLayer[i] : false);
        }
      }
      EditorGUILayout.EndVertical();

      EditorGUILayout.BeginVertical(GUI.skin.box);
      EditorGUILayout.LabelField("Copy Parameter(s)");
      if (sourceAnimator) {
        for (int i = 0; i < sourceAnimator.parameters.Length; i++ ) {
          copyParameter[i] = EditorGUILayout.Toggle(sourceAnimator.parameters[i].name, copyParameter.ContainsKey(i) ? copyParameter[i] : false);
        }
      }
      EditorGUILayout.EndVertical();

      overrideBehavior = (OverrideBehavior)EditorGUILayout.EnumPopup(overrideBehavior);

      EditorGUI.BeginDisabledGroup(sourceAnimator == null || destinationAnimator == null);
      if (GUILayout.Button("Copy")) {
        ExecuteCopy(overrideBehavior);
      }
      EditorGUI.EndDisabledGroup();
    }

    IEnumerable<T> CopyList<T>(
      IEnumerable<T> dst,
      IEnumerable<T> src,
      System.Func<T, T, bool> predicate,
      System.Action<T, T> copy,
      OverrideBehavior overrideBehavior
    ) {
      var overrided = dst.Select(oldItem => {
        if (overrideBehavior == OverrideBehavior.Override) {
          var item = src.FirstOrDefault(a => predicate(a, oldItem));
          if (item != null) {
            copy(oldItem, item);
          }
        }

        return oldItem;
      });

      var added = src.Where(item => {
        if (overrideBehavior == OverrideBehavior.Add) {
          return true;
        }
        if (overrideBehavior == OverrideBehavior.DoNothing) {
          return false;
        }
        return dst.FirstOrDefault(oldItem => predicate(item, oldItem)) == null;
      });

      return overrided.Concat(added);
    }

    void ExecuteCopy(OverrideBehavior overrideBehavior)
    {
      var parameters = sourceAnimator.parameters.Where((parameter, i) => copyParameter.ContainsKey(i) && copyParameter[i]);
      var layers = sourceAnimator.layers.Where((layer, i) => copyLayer.ContainsKey(i) && copyLayer[i]);

      destinationAnimator.parameters = CopyList(
        destinationAnimator.parameters,
        parameters,
        (a, b) => a.name == b.name,
        (dst, src) => {
          dst.type = src.type;
          dst.type = src.type;
          dst.defaultBool = src.defaultBool;
          dst.defaultFloat = src.defaultFloat;
          dst.defaultInt = src.defaultInt;
        },
        overrideBehavior
      ).ToArray();
      destinationAnimator.layers = CopyList(
        destinationAnimator.layers,
        layers,
        (a, b) => a.name == b.name,
        (dst, src) => {
          dst.avatarMask = src.avatarMask;
          dst.blendingMode = src.blendingMode;
          dst.defaultWeight = src.defaultWeight;
          dst.iKPass = src.iKPass;
          dst.stateMachine = src.stateMachine;
          dst.syncedLayerAffectsTiming = src.syncedLayerAffectsTiming;
          dst.syncedLayerIndex = src.syncedLayerIndex;
        },
        overrideBehavior
      ).ToArray();
    }
  }
}
#endif