Prefab里面的Prefab关联问题

using UnityEngine;

#if UNITY_EDITOR
 using UnityEditor;
 using UnityEditor.Callbacks;
#endif

using System.Collections.Generic;

[ExecuteInEditMode]
public class PrefabInstance : MonoBehaviour
{

    public GameObject prefab;

#if UNITY_EDITOR
 // Struct of all components. Used for edit-time visualization and gizmo drawing
 public struct Thingy {
 public Mesh mesh;
 public Matrix4x4 matrix;
 public List<Material materials;
 }

 [System.NonSerializedAttribute] public List<Thingy things = new
List<Thingy ();

 void OnValidate () {

 things.Clear();

 if (enabled)
 Rebuild (prefab, Matrix4x4.identity);
 }


 void OnEnable () {
 things.Clear();
 if (enabled)
 Rebuild (prefab, Matrix4x4.identity);
 }

 void Rebuild (GameObject source, Matrix4x4 inMatrix) {

 if (!source)
 return;

 Matrix4x4 baseMat = inMatrix * Matrix4x4.TRS (-source.transform.position,
Quaternion.identity, Vector3.one);
 foreach (MeshRenderer mr in source.GetComponentsInChildren(typeof
(Renderer), true))
 {

 things.Add(new Thingy () {
 mesh = mr.GetComponent<MeshFilter().sharedMesh,
 matrix = baseMat * mr.transform.localToWorldMatrix,
 materials = new List<Material (mr.sharedMaterials)
 });

 }

 foreach (PrefabInstance pi in source.GetComponentsInChildren(typeof
(PrefabInstance), true))
 {
 if (pi.enabled && pi.gameObject.activeSelf)
 Rebuild (pi.prefab, baseMat * pi.transform.localToWorldMatrix);
 }
 }
 // Editor-time-only update: Draw the meshes so we can see the objects in the
scene view
 void Update () {
 if (EditorApplication.isPlaying)
 return;
 Matrix4x4 mat = transform.localToWorldMatrix;
 foreach (Thingy t in things)
 for (int i = 0; i < t.materials.Count; i++)
 Graphics.DrawMesh (t.mesh, mat * t.matrix, t.materials[i], gameObject.layer,
null, i);
 }

 // Picking logic: Since we don't have gizmos.drawmesh, draw a bounding cube
around each thingy
 void OnDrawGizmos () { DrawGizmos (new Color (0,0,0,0)); }
 void OnDrawGizmosSelected () { DrawGizmos (new Color (0,0,1,.2f)); }
 void DrawGizmos (Color col) {

 if (EditorApplication.isPlaying)
 return;

 Gizmos.color = col;
 Matrix4x4 mat = transform.localToWorldMatrix;
 foreach (Thingy t in things)
 {
 Gizmos.matrix = mat * t.matrix;
 Gizmos.DrawCube(t.mesh.bounds.center, t.mesh.bounds.size);
 }
 }

 // Baking stuff: Copy in all the referenced objects into the scene on play
or build
 [PostProcessScene(-2)]
 public static void OnPostprocessScene() {
 foreach (PrefabInstance pi in UnityEngine.Object.FindObjectsOfType (typeof
(PrefabInstance)))
      BakeInstance (pi);
 }

 public static void BakeInstance (PrefabInstance pi) {
 if(!pi.prefab || !pi.enabled)
 return;

 pi.enabled = false;
 GameObject go = PrefabUtility.InstantiatePrefab(pi.prefab) as GameObject;
 Quaternion rot = go.transform.localRotation;
 Vector3 scale = go.transform.localScale;
 go.transform.parent = pi.transform;
 go.transform.localPosition = Vector3.zero;
 go.transform.localScale = scale;
 go.transform.localRotation = rot;
 pi.prefab = null;

 foreach (PrefabInstance childPi in
go.GetComponentsInChildren<PrefabInstance())
 BakeInstance (childPi);
 }
#endif
}