相关技术：Text、TextMesh、Rigidbody（刚体）、BoxCollider（碰撞体）、TextGenerator、文本网格、文字网格

 

原理：使用UGUI Text获取其文字的每个字符网格坐标，转世界坐标生成对应的3D文本(TextMesh)并挂上刚体、碰撞体实现掉落。

UGUI Text直接挂Canvas(World Space) 将它挪到镜头前，然后我是调整它的透明度为0的（不会影响网格生成），并挂载Gravity3DText组件，Gravity3DText组件参数拖拽自身Canvas和一个TextMesh物体预制体（3D文本），运行游戏后点击空格生成3D文本

预制体组件情况：

UGUI Text物体组件情况：

地板物体：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class Gravity3DText : MonoBehaviour
{
    public Canvas canvas;
    public GameObject gravity3DTextPrefab;
    private Text textMesh;
    private List<GameObject> tempTextList;

    public class CharData
    {
        public Vector3 pos;
        public Vector2 size;
    }

    void Start()
    {
        tempTextList = new List<GameObject>();
        textMesh = GetComponent<Text>();
        textMesh.GraphicUpdateComplete();
    }

    public void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            string textStr = textMesh.text;
            int textLength = textStr.Length;
            TextGenerator textGenerator = new TextGenerator(textLength);
            Vector2 size = textMesh.rectTransform.rect.size;
            textGenerator.Populate(textStr, textMesh.GetGenerationSettings(size));

            List<UIVertex> vertexList = textGenerator.verts as List<UIVertex>;            

            List<CharData> charDataList = new List<CharData>();
            for (int i = 0; i <= vertexList.Count - 4; i += 4)
            {
                CharData charData = new CharData();

                Vector3 pos1 = vertexList[i].position;
                Vector3 pos2 = vertexList[i + 1].position;
                Vector3 pos3 = vertexList[i + 2].position;
                Vector3 pos4 = vertexList[i + 3].position;

                Vector3 pos = (pos1 + pos2 + pos3 + pos4) / 4.0f;

                pos /= canvas.scaleFactor;
                charData.pos = pos;

                Vector3 charMinPos = Vector3.Min(pos1, pos2);
                charMinPos = Vector3.Min(charMinPos, pos3);
                charMinPos = Vector3.Min(charMinPos, pos4);

                Vector3 charMaxPos = Vector3.Max(pos1, pos2);
                charMaxPos = Vector3.Max(charMaxPos, pos3);
                charMaxPos = Vector3.Max(charMaxPos, pos4);

                charData.size = new Vector2(charMaxPos.x - charMinPos.x, charMaxPos.y - charMinPos.y);

                charDataList.Add(charData);
            }

            //统一字体大小            
            float sameY = transform.localPosition.y;
            string trimStr = textStr.Replace(" ", "");
            Debug.Log("trimStr:" + trimStr);
            int subMeshCount = Mathf.Min(textMesh.text.Length, charDataList.Count);
            for (int i = 0; i < subMeshCount; i++)
            {
                CharData charData = charDataList[i];
                Vector3 pos = transform.TransformPoint(charData.pos);
                pos.y = sameY;

                Debug.Log($"第{i + 1}个字,中心点:{pos}, size:{charData.size}, char:{trimStr[i]}");
                GameObject tempTextGo = GameObject.Instantiate(gravity3DTextPrefab);
                Transform tempTextTrans = tempTextGo.transform;
                tempTextTrans.position = pos;
                TextMesh tempTextMesh = tempTextGo.GetComponent<TextMesh>();
                tempTextMesh.text = trimStr[i].ToString();
                tempTextMesh.fontSize = textMesh.fontSize * 5;
                tempTextMesh.characterSize = 10 / 5; //minSize;
                tempTextList.Add(tempTextGo);
            }
        }
    }

    private void OnDestroy()
    {
        foreach (var v in tempTextList)
        {
            GameObject.Destroy(v);
        }
        tempTextList.Clear();
    }
}