QQ图片20170815153011.png

脚本挂在摄像机上，

Target Object（创建一个空物体，指定位置为目标物体中心，照相机可绕周围旋转）

按下鼠标左键改变视角，中键放大视角。

using UnityEngine;
using System.Collections;

public class CameraRotate : MonoBehaviour
{
public Transform targetObject;
public Vector3 targetOffset;
public float averageDistance = 5.0f;
public float maxDistance = 20;
public float minDistance = .6f;
public float xSpeed = 200.0f;
public float ySpeed = 200.0f;
public int yMinLimit = -80;
public int yMaxLimit = 80;
public int zoomSpeed = 40;
public float panSpeed = 0.3f;
public float zoomDampening = 5.0f;
public float rotateOnOff = 1;

private float xDeg = 0.0f;
private float yDeg = 0.0f;
private float currentDistance;
private float desiredDistance;
private Quaternion currentRotation;
private Quaternion desiredRotation;
private Quaternion rotation;
private Vector3 position;
private float idleTimer = 0.0f;
private float idleSmooth = 0.0f;

void Start() { Init(); }
void OnEnable() { Init(); }

public void Init()
{
    if (!targetObject)
    {
        GameObject go = new GameObject("Cam Target");
        go.transform.position = transform.position + (transform.forward * averageDistance);
        targetObject = go.transform;
    }

    currentDistance = averageDistance;
    desiredDistance = averageDistance;
    
    position = transform.position;
    rotation = transform.rotation;
    currentRotation = transform.rotation;
    desiredRotation = transform.rotation;
   
    xDeg = Vector3.Angle(Vector3.right, transform.right );
    yDeg = Vector3.Angle(Vector3.up, transform.up );
    position = targetObject.position - (rotation * Vector3.forward * currentDistance + targetOffset);
}

void LateUpdate()
{  
    if (Input.GetMouseButton(2) && Input.GetKey(KeyCode.LeftAlt) && Input.GetKey(KeyCode.LeftControl))
    {
        desiredDistance -= Input.GetAxis("Mouse Y") * 0.02f  * zoomSpeed*0.125f * Mathf.Abs(desiredDistance);
    }
    else if (Input.GetMouseButton(0) )
    {
        xDeg += Input.GetAxis("Mouse X") * xSpeed * 0.02f;
        yDeg -= Input.GetAxis("Mouse Y") * ySpeed * 0.02f;
        yDeg = ClampAngle(yDeg, yMinLimit, yMaxLimit);
        
        desiredRotation = Quaternion.Euler(yDeg, xDeg, 0);
        currentRotation = transform.rotation;
        rotation = Quaternion.Lerp(currentRotation, desiredRotation, 0.02f  * zoomDampening);
        transform.rotation = rotation;
        idleTimer=0;
        idleSmooth=0;
   
    }else{
        idleTimer+=0.02f ;
        if(idleTimer > rotateOnOff && rotateOnOff > 0){
            idleSmooth+=(0.02f +idleSmooth)*0.005f;
            idleSmooth = Mathf.Clamp(idleSmooth, 0, 1);
            xDeg += xSpeed * 0.001f * idleSmooth;
        }

        yDeg = ClampAngle(yDeg, yMinLimit, yMaxLimit);
        desiredRotation = Quaternion.Euler(yDeg, xDeg, 0);
        currentRotation = transform.rotation;
        rotation = Quaternion.Lerp(currentRotation, desiredRotation, 0.02f  * zoomDampening*2);
        transform.rotation = rotation;
    }

    desiredDistance -= Input.GetAxis("Mouse ScrollWheel") * 0.02f  * zoomSpeed * Mathf.Abs(desiredDistance);
    desiredDistance = Mathf.Clamp(desiredDistance, minDistance, maxDistance);
    currentDistance = Mathf.Lerp(currentDistance, desiredDistance, 0.02f  * zoomDampening);
    position = targetObject.position - (rotation * Vector3.forward * currentDistance + targetOffset);
    transform.position = position;
}

private static float ClampAngle(float angle, float min, float max)
{
    if (angle < -360)
        angle += 360;
    if (angle > 360)
        angle -= 360;
    return Mathf.Clamp(angle, min, max);
}
}