何谓第三人称?就像这样:

用wasd控制人物移动,同时保持在相机的中心。用鼠标右键与滚轮控制相机的角度和距离。
先说一下人物的移动:
首先给作为主角的单位加上 Charactor Controller组件,并调整胶囊型的碰撞体刚好包裹住主角(有其是脚底,除非你想看到你的主角能遁地,或飞行)

然后给你的人物加上控制的脚本~
using UnityEngine;
using System.Collections; public class move_controll : MonoBehaviour {
Transform m_transform,m_camera;//人物自己以及相机的对象
CharacterController controller;//Charactor Controller组件
public float MoveSpeed = 20.0f;//移动的速度
// Use this for initialization
void Start () {
m_transform = this.transform;//尽量不要再update里获取this.transform,而是这样保存起来,这样能节约性能
m_camera = GameObject.FindGameObjectWithTag ("MainCamera").transform;//
controller=GetComponent();
}
// Update is called once per frame
void Update () {
if ((Input.GetKey (KeyCode.W)) || (Input.GetKey (KeyCode.S)) || (Input.GetKey (KeyCode.A)) || (Input.GetKey (KeyCode.D))) {
transform.GetComponent().SetFloat("speed", "run");//将人物的动画改为移动状态,这里有个问题,就是动画组件的获取也要在update里获取,请读者自行修改吧
if (Input.GetKey (KeyCode.W)) {
//根据主相机的朝向决定人物的移动方向,下同
controller.transform.eulerAngles = new Vector3 (, m_camera.transform.eulerAngles.y, );
} if (Input.GetKey (KeyCode.S)) {
controller.transform.eulerAngles = new Vector3 (, m_camera.transform.eulerAngles.y+180f, );
} if (Input.GetKey (KeyCode.A)) {
controller.transform.eulerAngles = new Vector3 (, m_camera.transform.eulerAngles.y+270f, );
} if (Input.GetKey (KeyCode.D)) {
controller.transform.eulerAngles = new Vector3 (, m_camera.transform.eulerAngles.y+90f, );
} controller.Move(m_transform.forward * Time.deltaTime * MoveSpeed);
}
else
//静止状态
transform.GetComponent().SetFloat("speed", "stand");
if (Input.GetKey (KeyCode.Q)) {
transform.Translate (Vector3.up * Time.deltaTime * MoveSpeed);
}
if (!controller.isGrounded) {
//模拟简单重力,每秒下降10米,当然你也可以写成抛物线
controller.Move(new Vector3(,-10f*Time.deltaTime,));
}
}
然后是相机控制的脚本,从别的地方抄的,应该也不难理解,绑定在场景主相机上即可:
using UnityEngine; public class CameraOrbit : MonoBehaviour
{
public Transform pivot; // the object being followed
public Vector3 pivotOffset = Vector3.zero; // offset from target's pivot
public Transform target; // like a selected object (used with checking if objects between cam and target) public float distance = 10.0f; // distance from target (used with zoom)
public float minDistance = 2f;
public float maxDistance = 15f;
public float zoomSpeed = 1f; public float xSpeed = 250.0f;
public float ySpeed = 120.0f; public bool allowYTilt = true;
public float yMinLimit = 30f;
public float yMaxLimit = 80f; private float x = 0.0f;
private float y = 0.0f; private float targetX = 0f;
private float targetY = 0f;
private float targetDistance = 0f;
private float xVelocity = 1f;
private float yVelocity = 1f;
private float zoomVelocity = 1f; void Start()
{
var angles = transform.eulerAngles;
targetX = x = angles.x;
targetY = y = ClampAngle(angles.y, yMinLimit, yMaxLimit);
targetDistance = distance;
} void LateUpdate()
{
if (pivot)
{
float scroll = Input.GetAxis("Mouse ScrollWheel"); if (scroll > 0.0f) targetDistance -= zoomSpeed;
else if (scroll < 0.0f) targetDistance += zoomSpeed;
targetDistance = Mathf.Clamp(targetDistance, minDistance, maxDistance); // -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// right mouse button must be held down to tilt/rotate cam
// or player can use the left mouse button while holding Ctr
if (Input.GetMouseButton() || (Input.GetMouseButton() && (Input.GetKey(KeyCode.LeftControl) || Input.GetKey(KeyCode.RightControl)) ))
{
targetX += Input.GetAxis("Mouse X") * xSpeed * 0.02f;
if (allowYTilt)
{
targetY -= Input.GetAxis("Mouse Y") * ySpeed * 0.02f;
targetY = ClampAngle(targetY, yMinLimit, yMaxLimit);
}
}
x = Mathf.SmoothDampAngle(x, targetX, ref xVelocity, 0.3f);
if (allowYTilt) y = Mathf.SmoothDampAngle(y, targetY, ref yVelocity, 0.3f);
else y = targetY;
Quaternion rotation = Quaternion.Euler(y, x, );
distance = Mathf.SmoothDamp(distance, targetDistance, ref zoomVelocity, 0.5f); // -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// apply
Vector3 position = rotation * new Vector3(0.0f, 0.0f, -distance) + pivot.position + pivotOffset;
transform.rotation = rotation;
transform.position = position; }
} private float ClampAngle(float angle, float min, float max)
{
if (angle < -) angle += ;
if (angle > ) angle -= ;
return Mathf.Clamp(angle, min, max);
}
}