MaterialPropertyBlock会打断合并批次

MonoTestMaterialPropertyBlock.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;

[RequireComponent(typeof(SkinnedMeshRenderer))]
public class MonoTestMaterialPropertyBlock : MonoBehaviour
{
    public bool UseMPB;
    
    public bool bEnable;
    public float _DissolveFactor = 0;
    public bool _DissolveEnable = false;

    private SkinnedMeshRenderer r;
    private MaterialPropertyBlock mpb;
   
    
    private void Awake()
    {
        mpb = new MaterialPropertyBlock();
    }

    private void Update()
    {
        if (!bEnable)
        {
            return;
        }

        if (r == null)
        {
            r = this.gameObject.GetComponent<SkinnedMeshRenderer>();
        }

        if (r == null)
        {
            return;
        }
        
        if (UseMPB)
        {
            r.GetPropertyBlock(mpb);        
        }

        foreach (var it in r.sharedMaterials)
        {
            if (_DissolveEnable)
            {
                it.EnableKeyword("_DISSOLVE_EFFECT");   
            }
            else
            {
                it.DisableKeyword("_DISSOLVE_EFFECT");
            }
            
            if (UseMPB)
            {
                mpb.SetFloat("_DissolveAmount", _DissolveFactor);
            }
            else
            {
                it.SetFloat("_DissolveAmount", _DissolveFactor);
            }
        }

        if (UseMPB)
        {
            r.SetPropertyBlock(mpb);        
        }
    }
}