获取摄像机的视口区域

先上代码
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class test : MonoBehaviour {

private Camera theCamera;

public float distance = 8.5f;
private Transform tran;
void Start () {

    if(!theCamera)
    {
        theCamera = Camera.main;
    }
    //float temp = (float)Screen.width  /(float) Screen.height;
    //Debug.Log(temp);
    //Debug.Log(theCamera.aspect ); 
    tran = theCamera.transform;
  //  Debug.Log(theCamera.aspect); 
}

void Update () {
    FindCorners();
}

void FindCorners()
{
    Vector3[] corner = GetCorners(distance);

    Debug.DrawLine(corner[0],corner[1],Color.red);
    Debug.DrawLine(corner[1], corner[3], Color.red);
    Debug.DrawLine(corner[3], corner[2], Color.red);
    Debug.DrawLine(corner[2], corner[0], Color.red);
}

Vector3[] GetCorners(float tempDistance)
{
    Vector3[] corners = new Vector3[4];
    //  角度转化为弧度（照相机视野的一半）
    float halfOV = (theCamera.fieldOfView * 0.5f) * Mathf.Deg2Rad;
    Debug.Log(halfOV);
    float aspect = theCamera.aspect;
    //  这里算出来的宽和高都是视口矩形的一半
    float height = tempDistance * Mathf.Tan(halfOV);

    float width = height * aspect;

    // 左上
    corners[0] = tran.position - (tran.right * width);
    corners[0] += tran.up * height;
    corners[0] += tran.forward * tempDistance;

    // 右上
    corners[1] = tran.position + (tran.right * width);
    corners[1] += tran.up * height;
    corners[1] += tran.forward * tempDistance;

    // 左下
    corners[2] = tran.position - (tran.right * width);
    corners[2] -= tran.up * height;
    corners[2] += tran.forward * tempDistance;

    // 右下
    corners[3] = tran.position + (tran.right * width);
    corners[3] -= tran.up * height;
    corners[3] += tran.forward * tempDistance;

    return corners;

}

}

运行结果如下

这样就知道了摄像机的视口区域，接下来想做一些视口坐标的操作就简单了