如何在Unity中读取JSON文件的Speed参数并控制角色移动

需求说明 #

需要读取指定JSON文件中的Speed参数，将其作为Unity Inspector可配置参数，以此控制Agent或角色的移动速度，目前已完成基础JSON读取脚本，需补充移动控制逻辑。

待读取的JSON文件内容 #

{
"player": [
    {
        "X":7.214575709504705,
        "Z":28.484783109249697,
        "ID":"116",
        "Speed":1.0
    }
  ]
}

当前已编写的JsonReader脚本 #

using System.Collections.Generic;
using UnityEngine;

public class Reader : MonoBehaviour
{
public TextAsset jsonData;
public PlayerList players = new PlayerList();

[System.Serializable]
public class Player
{
    public float X;
    public float Z;
    public string ID;
    public float Speed;
}
[System.Serializable]
public class PlayerList
{
    public Player[] player;
}
// Start is called before the first frame update
void Start()
{
    players = JsonUtility.FromJson<PlayerList>(jsonData.text);
}
}

实现步骤 #

1. 读取并暴露Speed参数到Inspector #

在Reader类中添加公开字段存储当前速度，在Start方法中从JSON读取赋值，这样参数会显示在Inspector中，方便查看或临时调整：

public float currentSpeed; // 该字段会显示在Inspector面板

void Start()
{
    players = JsonUtility.FromJson<PlayerList>(jsonData.text);
    // 读取数组中第一个玩家的Speed值（可根据需求按ID筛选）
    if(players.player != null && players.player.Length > 0)
    {
        currentSpeed = players.player[0].Speed;
    }
}

2. 添加角色移动控制逻辑 #

根据角色使用的组件（CharacterController/Rigidbody）编写移动代码，以下是基于CharacterController的示例：

using UnityEngine;

public class Reader : MonoBehaviour
{
    public TextAsset jsonData;
    public PlayerList players = new PlayerList();
    public float currentSpeed;
    private CharacterController controller;

    [System.Serializable]
    public class Player
    {
        public float X;
        public float Z;
        public string ID;
        public float Speed;
    }
    [System.Serializable]
    public class PlayerList
    {
        public Player[] player;
    }

    void Start()
    {
        // 获取角色的CharacterController组件
        controller = GetComponent<CharacterController>();
        players = JsonUtility.FromJson<PlayerList>(jsonData.text);
        if(players.player != null && players.player.Length > 0)
        {
            currentSpeed = players.player[0].Speed;
        }
    }

    void Update()
    {
        // 用WASD控制角色移动，速度由JSON读取的currentSpeed决定
        float horizontal = Input.GetAxis("Horizontal");
        float vertical = Input.GetAxis("Vertical");
        Vector3 moveDir = transform.right * horizontal + transform.forward * vertical;
        controller.Move(moveDir * currentSpeed * Time.deltaTime);
    }
}

3. 注意事项 #

• 确保JSON文件在Unity中被设置为TextAsset类型（选中文件后，Inspector的Import Settings设为Text）
• 若角色使用Rigidbody组件，需将移动逻辑改为修改rigidbody.velocity，避免与CharacterController冲突
• 若JSON包含多个Player对象，可通过遍历数组匹配ID来获取对应角色的Speed值

内容的提问来源于stack exchange，提问作者ambioss