c# - 使用 Unity3D 相机平滑跟随 2D 从 UnityScript 到 C#

Question

我正在制作一个脚本，用于 Unity3D 的主相机对象，以便相机跟随 2D 平台游戏世界中的角色。

我尝试将其从 UnityScript 脚本转换为 C#，在第 26 行中收到错误:“无法修改‘UnityEngine.Transform.position’的值类型返回值。请考虑将该值存储在临时变量中。 ”

原始 UnityScript 版本

var cameraTarget : GameObject;
var player : GameObject;

var smoothTime : float = 0,1;
var cameraFollowX : boolean = true;
var cameraFollowY : boolean = true;
var cameraFollowHeight : boolean = false;
var cameraHeight : float = 2.5;
var velocity : Vector2;
private var thisTransform : Transform;

function Start ()
{
  thisTransform = transform;
}

function Update () 
{

if (cameraFollowX)
{
  thisTransform.position.x = Mathf.SmoothDamp (thisTransform.position.x, cameraTarget.transform.position.x, velocity.x, smoothTime);
}

if (cameraFollowY)
{
  thisTransform.position.y = Mathf.SmoothDamp (thisTransform.position.y, cameraTarget.transform.position.y, velocity.y, smoothTime);
}

if (!cameraFollowX & cameraFollowHeight)
{
  camera.transform.position.y = cameraHeight;
}

}

我的 C# 版本

using UnityEngine;
using System.Collections;

public class CameraSmoothFollow : MonoBehaviour {

    public GameObject cameraTarget; // object to look at or follow
    public GameObject player; // player object for moving

    public float smoothTime = 0.1f; // time for dampen
    public bool cameraFollowX = true; // camera follows on horizontal
    public bool cameraFollowY = true; // camera follows on vertical
    public bool cameraFollowHeight = true; // camera follow CameraTarget object height
    public float cameraHeight = 2.5f; // height of camera adjustable
    public Vector2 velocity; // speed of camera movement

    private Transform thisTransform; // camera Transform

    // Use this for initialization
    void Start () {
        thisTransform = transform;
    }

    // Update is called once per frame
    void Update () {
        if (cameraFollowX){
            thisTransform.position.x = Mathf.SmoothDamp (thisTransform.position.x, cameraTarget.transform.position.x, ref velocity.x, smoothTime); // Here i get the error
        }
        if (cameraFollowY) {
        // to do    
        }
        if (!cameraFollowX & cameraFollowHeight) {
        // to do
        }
    }
}

任何帮助将不胜感激。

Answer 1

发生此错误的原因是 Transform.position 是值类型(可能是 struct)。这意味着当您访问 position 的 X 属性时，您访问的是副本而不是真实的东西。要分配给位置属性，您需要创建一个新的 Vector3 并将其分配给位置属性。您的代码将如下所示:

thisTransform.position = new Vector3 (Mathf.SmoothDamp (thisTransform.position.x, cameraTarget.transform.position.x, ref velocity.x, smoothTime), thisTransform.position.y, thisTransform.position.z);

或者也许更干净:

float tempX = new Vector3 (Mathf.SmoothDamp (thisTransform.position.x, cameraTarget.transform.position.x, ref velocity.x, smoothTime);
thisTransform.position = new Vector3 (tempX, thisTransform.position.y, thisTransform.position.z);