Unity3D读取txt文件坐标实现双车同步移动方案咨询

1. 定义匹配JSON结构的C#类 #

先创建对应JSON层级的可序列化类，确保Unity能正确解析数据：

[System.Serializable]
public class CarPositionData
{
    public string id;
    public PositionInfo position;
}

[System.Serializable]
public class PositionInfo
{
    public float[] cartesian;
}

2. 读取文件内容 #

根据文件存放位置选择读取方式：

• 放在StreamingAssets文件夹：

using System.IO;
using UnityEngine;

string filePath = Path.Combine(Application.streamingAssetsPath, "positions.txt");
string jsonContent = File.ReadAllText(filePath);

• 放在Resources文件夹：

TextAsset jsonText = Resources.Load<TextAsset>("positions");
string jsonContent = jsonText.text;

3. 解析JSON并拆分坐标数据 #

方法一：用Unity自带JsonUtility（处理顶层数组） #

Unity原生JsonUtility不支持直接解析顶层数组，需用辅助类包裹处理：

public static class JsonHelper
{
    public static T[] FromJson<T>(string json)
    {
        string wrappedJson = "{\"items\":" + json + "}";
        Wrapper<T> wrapper = JsonUtility.FromJson<Wrapper<T>>(wrappedJson);
        return wrapper.items;
    }

    [System.Serializable]
    private class Wrapper<T>
    {
        public T[] items;
    }
}

然后解析并拆分cartesian数组为时间序列和位置序列：

// 解析所有车辆数据
CarPositionData[] carDatas = JsonHelper.FromJson<CarPositionData>(jsonContent);

// 存储每辆车的时间、位置数据
var carMovementDict = new Dictionary<string, (float[] times, Vector3[] positions)>();

foreach (var carData in carDatas)
{
    float[] cartesian = carData.position.cartesian;
    int dataGroupCount = cartesian.Length / 4;
    float[] times = new float[dataGroupCount];
    Vector3[] positions = new Vector3[dataGroupCount];

    for (int i = 0; i < dataGroupCount; i++)
    {
        int baseIndex = i * 4;
        times[i] = cartesian[baseIndex];
        positions[i] = new Vector3(
            cartesian[baseIndex + 1],
            cartesian[baseIndex + 2],
            cartesian[baseIndex + 3]
        );
    }

    carMovementDict.Add(carData.id, (times, positions));
}

方法二：用Newtonsoft.Json（更简便） #

通过Unity Package Manager安装com.unity.nuget.newtonsoft-json包后，可直接解析顶层数组：

using Newtonsoft.Json;

CarPositionData[] carDatas = JsonConvert.DeserializeObject<CarPositionData[]>(jsonContent);

后续拆分数组的逻辑和方法一完全一致。

4. 实现汽车同步移动 #

创建控制汽车移动的脚本，挂载到每辆汽车上：

using UnityEngine;

public class CarMovement : MonoBehaviour
{
    public string carId;
    private float[] _timeSequence;
    private Vector3[] _positionSequence;
    private int _currentDataIndex = 0;
    private float _movementStartTime;

    public void Initialize(float[] times, Vector3[] positions)
    {
        _timeSequence = times;
        _positionSequence = positions;
        _movementStartTime = Time.time;
    }

    void Update()
    {
        if (_timeSequence == null || _positionSequence == null || _currentDataIndex >= _timeSequence.Length - 1)
            return;

        float elapsedTime = Time.time - _movementStartTime;

        // 定位当前时间对应的区间
        while (_currentDataIndex < _timeSequence.Length - 1 && elapsedTime > _timeSequence[_currentDataIndex + 1])
        {
            _currentDataIndex++;
        }

        // 到达最后一个点时固定位置
        if (_currentDataIndex >= _timeSequence.Length - 1)
        {
            transform.position = _positionSequence[^1];
            return;
        }

        // 计算插值比例并移动
        float t = (elapsedTime - _timeSequence[_currentDataIndex]) / (_timeSequence[_currentDataIndex + 1] - _timeSequence[_currentDataIndex]);
        transform.position = Vector3.Lerp(_positionSequence[_currentDataIndex], _positionSequence[_currentDataIndex + 1], t);
    }
}

最后在控制脚本中初始化所有汽车：

public class MovementController : MonoBehaviour
{
    public GameObject car1;
    public GameObject car2;

    void Start()
    {
        // 放入前面的文件读取、解析代码...

        // 初始化car1
        if (carMovementDict.ContainsKey("car_1"))
        {
            var data = carMovementDict["car_1"];
            car1.GetComponent<CarMovement>().Initialize(data.times, data.positions);
        }

        // 初始化car2
        if (carMovementDict.ContainsKey("car_2"))
        {
            var data = carMovementDict["car_2"];
            car2.GetComponent<CarMovement>().Initialize(data.times, data.positions);
        }
    }
}

内容的提问来源于stack exchange，提问作者alcor