Unity3D 学习笔记(八) 锁定目标与 Physics.OverlapBox

添加所需变量

添加变量

    public bool lockon;

新button

    public Button lockButton = new Button();

以及

    lockButton.Tick(Input.GetKey(keyLock));

        lockon =  lockButton.OnPressed;

调取这个信号

    if(pi.lockon){camcon.LockSwitch();}

在CameraController中

public void LockSwitch(){print("lock");}

尝试lock可以正常调用

利用OverlapBox检测碰撞

检测target使用API Physics.OverlapBox

public static Collider[] **OverlapBox**([Vector3](https://docs.unity3d.com/ScriptReference/Vector3.html) **center**, [Vector3](https://docs.unity3d.com/ScriptReference/Vector3.html) **halfExtents**, [Quaternion](https://docs.unity3d.com/ScriptReference/Quaternion.html) **orientation** = Quaternion.identity, int **layerMask** = AllLayers, [QueryTriggerInteraction](https://docs.unity3d.com/ScriptReference/QueryTriggerInteraction.html) **queryTriggerInteraction** = QueryTriggerInteraction.UseGlobal);

参数 Vector3类型的BOX中心，三个维度下BOX的半长组成的Vector3，Quaternion类型的BOX的方向，碰撞的Layer，默认为所以的Layer，最后的queryTrigger暂时不需要。

返回值为与BOX碰撞的Collider

在CameraController中声明新变量

private GameObject lockTarget;

完善LockSwitch函数，使其能计算出锁定目标，将其赋值给lockTarget

public void LockSwitch(){print("lock");//if(lockTarget == null){//try to lock othersVector3 modelOrigin1 = model.transform.position;Vector3 modelOrigin2 = modelOrigin1 + new Vector3(0,1,0);//计算出人脑袋的位置 Vector3 boxCenter = modelOrigin2 + model.transform.forward *5.0f;//???Collider[] cols = Physics.OverlapBox(boxCenter,new Vector3(0.5f,0.5f,5f),model.transform.rotation,LayerMask.GetMask("Enemy"));if(cols.Length == 0){lockTarget = null;}else {foreach(var col in cols){//print(col.name);if(lockTarget == col.gameObject){lockTarget = null;print("lock cancel");break;}else{lockTarget = col.gameObject;print(lockTarget);break;}}}}

修改相机控制中的追踪部分，当无目标时与原来相同，有锁定目标时视线始终看向目标并调整角色朝向

void FixedUpdate(){if(lockTarget == null){Vector3 tempModeEuler = model.transform.eulerAngles;playerHandle.transform.Rotate(Vector3.up,pi.Jright * horizontalSpeed *Time.fixedDeltaTime);//cameraHandle.transform.Rotate(Vector3.right,pi.Jup * -verticalSpeed *Time.deltaTime);//tempEulerX = cameraHandle.transform.eulerAngles.x;tempEulerX -= pi.Jup * verticalSpeed *Time.deltaTime;tempEulerX = Mathf.Clamp(tempEulerX,-40,30);cameraHandle.transform.localEulerAngles = new Vector3(tempEulerX,0,0);model.transform.eulerAngles = tempModeEuler;}else {Vector3 tempForward = lockTarget.transform.position - model.transform.position;tempForward.y = 0;playerHandle.transform.forward = tempForward;}cam.transform.position = Vector3.SmoothDamp(cam.transform.position,transform.position,ref cameraDampVelocity,0.5f);//cam.transform.eulerAngles = transform.eulerAngles;cam.transform.LookAt(cameraHandle.transform);//一直看着camerahandle}

可以实现视角的锁定

显示锁定目标的圆圈

创建一个UI里面的Image

选择合适的图形、大小、颜色（在game窗口看到这个image）

在cameraController中添加

using UnityEngine.UI;

public Image lockDot;

在start中使其初始不可用

lockDot.enabled = false;

在分支中添加对应的启用和禁用

此时进游戏发现点在视野中央，但是由于摄像机的跟随效果所以其与锁定目标有所便宜，因此在FixedUpdate中的有锁定目标分支添加

lockDot.transform.position = Camera.main.WorldToScreenPoint (lockTarget.transform.position);

再打开游戏，可以实现效果