【Unity】TextMeshPro のテキストメッシュの頂点をランダムにずらす

using System.Collections;
using TMPro;
using UnityEngine;

[RequireComponent(typeof(TextMeshProUGUI))]
public class TextShake : MonoBehaviour
{
    [SerializeField]
    private float _interval = 0.5f;

    [SerializeField]
    private float _maxOffset = 10f;
    
    private IEnumerator Start()
    {
        var component = GetComponent<TMP_Text>();
        
        component.ForceMeshUpdate();
        
        var textInfo = component.textInfo;
        
        var cachedMeshInfo = textInfo.CopyMeshInfoVertexData();
        
        var cc = textInfo.characterCount;

        while (true)
        {
            for (var characterIndex = 0; characterIndex < cc; characterIndex++)
            {
                var charInfo = textInfo.characterInfo[characterIndex];
                if (!charInfo.isVisible)
                    continue;
                
                var materialIndex = charInfo.materialReferenceIndex;
                var vertexIndex = charInfo.vertexIndex;
                
                // もともとの頂点情報
                var sourceVertices = cachedMeshInfo[materialIndex].vertices;
                
                // 現在の頂点情報を取得して上書き
                var destinationVertices = textInfo.meshInfo[materialIndex].vertices;
                for (var i = 0; i < 4; i++)
                {
                    var index = vertexIndex + i;
                    for (var j = 0; j < 2; j++)
                    {
                         destinationVertices[index][j] = sourceVertices[index][j] + Random.Range(-_maxOffset, _maxOffset);
                    }
                }
            }
            
            // メッシュの変更
            for (var i = 0; i < textInfo.meshInfo.Length; i++)
            {
                textInfo.meshInfo[i].mesh.vertices = textInfo.meshInfo[i].vertices;
                component.UpdateGeometry(textInfo.meshInfo[i].mesh, i);
            }
            
            yield return new WaitForSeconds(_interval);
        }
    }
}