【Unity3D日常开发】（四）实现角色移动行走之官方Demo移动代码分析

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一、前言

我们在使用官方的资源包的时候，会发现官方案例中自带的人物控制器非常好用，下面就将官方的资源包中的人物控制器的脚本进行分析。

一是为了理解学习代码，二是为了让大家有一个清晰的认识。

下载资源包：

Unity2018官方标准资源包

有的就不用下载了，如果没有的话下载下来，导入到Unity中。

解压后，可以看到很多的.unitypackage后缀的文件：

将Characters.unitypackage这个文件导入到Unity中即可。

然后打开Assets->Standard Assets ->Characters ->FirstPersonCharacter ->Prefabs文件夹：

选择预制体拖入到场景中就可以使用了。

二、使用

有两个预制体

FPSController.cs

主要组件有Character Controller、脚本First Person Controller、Rigidbody
这个是FPS第一人称控制器，模拟FPS游戏中人物移动的方式，是第一人称控制器。
鼠标锁定，视角跟随鼠标移动而移动。WSAD控制人物移动

RigidBodyFPSController.cs

主要组件有Capsule Collider、脚本RigidBody First Person Controller
与FPSController控制器不同的一点是，一个是用CharacterController控制移动，一个是控制人物本身的刚体，给刚体添加一个方向力，就可以移动

三、脚本详细解析

第一人称控制器 FirstPersonController

using System;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;
using UnityStandardAssets.Utility;
using Random = UnityEngine.Random;

namespace UnityStandardAssets.Characters.FirstPerson
{
    //自动添加关联的脚本
    [RequireComponent(typeof (CharacterController))]
    [RequireComponent(typeof (AudioSource))]
    public class FirstPersonController : MonoBehaviour
    {
        //判断是否在走
        [SerializeField] private bool m_IsWalking;
        //走路的速度
        [SerializeField] private float m_WalkSpeed;
        //奔跑的速度
        [SerializeField] private float m_RunSpeed;
        //模仿随机行走的速度
        [SerializeField] [Range(0f, 1f)] private float m_RunstepLenghten;
        //跳跃速度
        [SerializeField] private float m_JumpSpeed;
        //判断是否在空中，如果在空中接给一个下降的力
        [SerializeField] private float m_StickToGroundForce;
        //重力
        [SerializeField] private float m_GravityMultiplier;
        //视角控制脚本
        [SerializeField] private MouseLook m_MouseLook;
        [SerializeField] private bool m_UseFovKick;
        //FovKick脚本
        [SerializeField] private FOVKick m_FovKick = new FOVKick();
        [SerializeField] private bool m_UseHeadBob;
        [SerializeField] private CurveControlledBob m_HeadBob = new CurveControlledBob();
        [SerializeField] private LerpControlledBob m_JumpBob = new LerpControlledBob();
        [SerializeField] private float m_StepInterval;
        [SerializeField] private AudioClip[] m_FootstepSounds;    // an array of footstep sounds that will be randomly selected from.
        [SerializeField] private AudioClip m_JumpSound;           // the sound played when character leaves the ground.
        [SerializeField] private AudioClip m_LandSound;           // the sound played when character touches back on ground.

        private Camera m_Camera;
        private bool m_Jump;
        private float m_YRotation;
        private Vector2 m_Input;
        private Vector3 m_MoveDir = Vector3.zero;
        private CharacterController m_CharacterController;
        private CollisionFlags m_CollisionFlags;
        private bool m_PreviouslyGrounded;
        private Vector3 m_OriginalCameraPosition;
        private float m_StepCycle;
        private float m_NextStep;
        private bool m_Jumping;
        private AudioSource m_AudioSource;

        // Use this for initialization
        private void Start()
        {
            m_CharacterController = GetComponent<CharacterController>();
            m_Camera = Camera.main;
            m_OriginalCameraPosition = m_Camera.transform.localPosition;
            m_FovKick.Setup(m_Camera);
            m_HeadBob.Setup(m_Camera, m_StepInterval);
            m_StepCycle = 0f;
            m_NextStep = m_StepCycle/2f;
            m_Jumping = false;
            m_AudioSource = GetComponent<AudioSource>();
			m_MouseLook.Init(transform , m_Camera.transform);
        }


        // Update is called once per frame
        private void Update()
        {
            //视角控制
            RotateView();
            // the jump state needs to read here to make sure it is not missed
            //跳转状态判断
            if (!m_Jump)
            {
                m_Jump = CrossPlatformInputManager.GetButtonDown("Jump");
            }
            //判断是否在地面上
            if (!m_PreviouslyGrounded && m_CharacterController.isGrounded)
            {
                StartCoroutine(m_JumpBob.DoBobCycle());
                PlayLandingSound();
                m_MoveDir.y = 0f;
                m_Jumping = false;
            }
            //不在地面上，并且不在跳跃状态
            if (!m_CharacterController.isGrounded && !m_Jumping && m_PreviouslyGrounded)
            {
                m_MoveDir.y = 0f;
            }

            m_PreviouslyGrounded = m_CharacterController.isGrounded;
        }

        //播放降落的声音
        private void PlayLandingSound()
        {
            m_AudioSource.clip = m_LandSound;
            m_AudioSource.Play();
            m_NextStep = m_StepCycle + .5f;
        }

        //控制人物行走
        private void FixedUpdate()
        {
            float speed;
            GetInput(out speed);
            // always move along the camera forward as it is the direction that it being aimed at
            //始终沿着摄像机向前移动，因为它是瞄准的方向
            Vector3 desiredMove = transform.forward*m_Input.y + transform.right*m_Input.x;

            // get a normal for the surface that is being touched to move along it
            //得到一个正常的表面，被触摸移动它
            RaycastHit hitInfo;
            Physics.SphereCast(transform.position, m_CharacterController.radius, Vector3.down, out hitInfo,
                               m_CharacterController.height/2f);
            desiredMove = Vector3.ProjectOnPlane(desiredMove, hitInfo.normal).normalized;

            m_MoveDir.x = desiredMove.x*speed;
            m_MoveDir.z = desiredMove.z*speed;


            if (m_CharacterController.isGrounded)
            {
                m_MoveDir.y = -m_StickToGroundForce;

                if (m_Jump)
                {
                    m_MoveDir.y = m_JumpSpeed;
                    PlayJumpSound();
                    m_Jump = false;
                    m_Jumping = true;
                }
            }
            else
            {
                m_MoveDir += Physics.gravity*m_GravityMultiplier*Time.fixedDeltaTime;
            }
            m_CollisionFlags = m_CharacterController.Move(m_MoveDir*Time.fixedDeltaTime);

            ProgressStepCycle(speed);
            UpdateCameraPosition(speed);
        }

        //播放跳跃的声音
        private void PlayJumpSound()
        {
            m_AudioSource.clip = m_JumpSound;
            m_AudioSource.Play();
        }


        private void ProgressStepCycle(float speed)
        {
            if (m_CharacterController.velocity.sqrMagnitude > 0 && (m_Input.x != 0 || m_Input.y != 0))
            {
                m_StepCycle += (m_CharacterController.velocity.magnitude + (speed*(m_IsWalking ? 1f : m_RunstepLenghten)))*
                             Time.fixedDeltaTime;
            }

            if (!(m_StepCycle > m_NextStep))
            {
                return;
            }

            m_NextStep = m_StepCycle + m_StepInterval;

            PlayFootStepAudio();
        }

        //播放脚本的声音
        private void PlayFootStepAudio()
        {
            if (!m_CharacterController.isGrounded)
            {
                return;
            }
            // pick & play a random footstep sound from the array,
            // excluding sound at index 0
            int n = Random.Range(1, m_FootstepSounds.Length);
            m_AudioSource.clip = m_FootstepSounds[n];
            m_AudioSource.PlayOneShot(m_AudioSource.clip);
            // move picked sound to index 0 so it's not picked next time
            m_FootstepSounds[n] = m_FootstepSounds[0];
            m_FootstepSounds[0] = m_AudioSource.clip;
        }

        //控制摄像机的视角移动
        private void UpdateCameraPosition(float speed)
        {
            Vector3 newCameraPosition;
            if (!m_UseHeadBob)
            {
                return;
            }
            if (m_CharacterController.velocity.magnitude > 0 && m_CharacterController.isGrounded)
            {
                m_Camera.transform.localPosition =
                    m_HeadBob.DoHeadBob(m_CharacterController.velocity.magnitude +
                                      (speed*(m_IsWalking ? 1f : m_RunstepLenghten)));
                newCameraPosition = m_Camera.transform.localPosition;
                newCameraPosition.y = m_Camera.transform.localPosition.y - m_JumpBob.Offset();
            }
            else
            {
                newCameraPosition = m_Camera.transform.localPosition;
                newCameraPosition.y = m_OriginalCameraPosition.y - m_JumpBob.Offset();
            }
            m_Camera.transform.localPosition = newCameraPosition;
        }

        //获得键盘输入
        private void GetInput(out float speed)
        {
            // Read input
            float horizontal = CrossPlatformInputManager.GetAxis("Horizontal");
            float vertical = CrossPlatformInputManager.GetAxis("Vertical");

            bool waswalking = m_IsWalking;

#if !MOBILE_INPUT
            // On standalone builds, walk/run speed is modified by a key press.
            // keep track of whether or not the character is walking or running
            m_IsWalking = !Input.GetKey(KeyCode.LeftShift);
#endif
            // set the desired speed to be walking or running
            speed = m_IsWalking ? m_WalkSpeed : m_RunSpeed;
            m_Input = new Vector2(horizontal, vertical);

            // normalize input if it exceeds 1 in combined length:
            if (m_Input.sqrMagnitude > 1)
            {
                m_Input.Normalize();
            }

            // handle speed change to give an fov kick
            // only if the player is going to a run, is running and the fovkick is to be used
            if (m_IsWalking != waswalking && m_UseFovKick && m_CharacterController.velocity.sqrMagnitude > 0)
            {
                StopAllCoroutines();
                StartCoroutine(!m_IsWalking ? m_FovKick.FOVKickUp() : m_FovKick.FOVKickDown());
            }
        }

        //选择视角到正常角度
        private void RotateView()
        {
            m_MouseLook.LookRotation (transform, m_Camera.transform);
        }

        //控制器碰撞反应
        private void OnControllerColliderHit(ControllerColliderHit hit)
        {
            Rigidbody body = hit.collider.attachedRigidbody;
            //dont move the rigidbody if the character is on top of it
            if (m_CollisionFlags == CollisionFlags.Below)
            {
                return;
            }

            if (body == null || body.isKinematic)
            {
                return;
            }
            body.AddForceAtPosition(m_CharacterController.velocity*0.1f, hit.point, ForceMode.Impulse);
        }
    }
}

其中核心的，让人物角色移动的代码：

m_CollisionFlags = m_CharacterController.Move(m_MoveDir*Time.fixedDeltaTime);

m_CollisionFlags 碰撞检测的旗标
m_CharacterController 角色的CharacterController组件
m_MoveDir 当前移动的方向乘上键盘获得的输入得到的值
Time.fixedDeltaTime 固定的时间增量

其中如果要解除鼠标锁定的话可以到这个脚本中修改。

鼠标视角脚本 MouseLook

		//更新鼠标锁定的状态的
		public void UpdateCursorLock()
        {
            //if the user set "lockCursor" we check & properly lock the cursos
            if (lockCursor)
                InternalLockUpdate();
        }
        //控制鼠标锁定
        private void InternalLockUpdate()
        {
            if (Input.GetKeyUp(KeyCode.Escape))
            {
                m_cursorIsLocked = false;
            }
            else if (Input.GetMouseButtonUp(1))
            {
                m_cursorIsLocked = true;
            }

            if (m_cursorIsLocked)
            {
                Cursor.lockState = CursorLockMode.Locked;
                Cursor.visible = false;
            }
            else if (!m_cursorIsLocked)
            {
                Cursor.lockState = CursorLockMode.None;
                Cursor.visible = true;
            }
        }

刚体第一人称控制器 RigidbodyFirstPersonController

using System;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;

namespace UnityStandardAssets.Characters.FirstPerson
{
    //自动添加关联的脚本
    [RequireComponent(typeof (Rigidbody))]
    [RequireComponent(typeof (CapsuleCollider))]
    public class RigidbodyFirstPersonController : MonoBehaviour
    {
        [Serializable]
        public class MovementSettings
        {
            //前进速度
            public float ForwardSpeed = 8.0f;   // Speed when walking forward
            //后退速度
            public float BackwardSpeed = 4.0f;  // Speed when walking backwards
            //走路时速度横向
            public float StrafeSpeed = 4.0f;    // Speed when walking sideways
            //奔跑的速度
            public float RunMultiplier = 2.0f;   // Speed when sprinting
            //奔跑键设置为LeftShift
	        public KeyCode RunKey = KeyCode.LeftShift;
            //跳跃的力
            public float JumpForce = 30f;
            //动画曲线，用在了模型动画播放时的碰撞盒缩放及重力调节
            public AnimationCurve SlopeCurveModifier = new AnimationCurve(new Keyframe(-90.0f, 1.0f), new Keyframe(0.0f, 1.0f), new Keyframe(90.0f, 0.0f));
            //当前的目标速度
            [HideInInspector] public float CurrentTargetSpeed = 8f;

#if !MOBILE_INPUT
            private bool m_Running;
#endif
            //更新所需的目标速度
            public void UpdateDesiredTargetSpeed(Vector2 input)
            {
	            if (input == Vector2.zero) return;
				if (input.x > 0 || input.x < 0)
				{
					//strafe
					CurrentTargetSpeed = StrafeSpeed;
				}
				if (input.y < 0)
				{
					//backwards
					CurrentTargetSpeed = BackwardSpeed;
				}
				if (input.y > 0)
				{
					//forwards
					//handled last as if strafing and moving forward at the same time forwards speed should take precedence
					CurrentTargetSpeed = ForwardSpeed;
				}
#if !MOBILE_INPUT
	            if (Input.GetKey(RunKey))
	            {
		            CurrentTargetSpeed *= RunMultiplier;
		            m_Running = true;
	            }
	            else
	            {
		            m_Running = false;
	            }
#endif
            }

#if !MOBILE_INPUT
            public bool Running
            {
                get { return m_Running; }
            }
#endif
        }

        //高级设置
        [Serializable]
        public class AdvancedSettings
        {
            //检查控制器是否接地的距离(0.01f似乎最适合这个)
            public float groundCheckDistance = 0.01f; // distance for checking if the controller is grounded ( 0.01f seems to work best for this )
            //停止这个角色
            public float stickToGroundHelperDistance = 0.5f; // stops the character
            //当没有输入时控制器到达停止的速度
            public float slowDownRate = 20f; // rate at which the controller comes to a stop when there is no input
            //用户能够控制在空气中移动的方向吗
            public bool airControl; // can the user control the direction that is being moved in the air
        }


        public Camera cam;
        public MovementSettings movementSettings = new MovementSettings();
        public MouseLook mouseLook = new MouseLook();
        public AdvancedSettings advancedSettings = new AdvancedSettings();


        private Rigidbody m_RigidBody;
        private CapsuleCollider m_Capsule;
        private float m_YRotation;
        private Vector3 m_GroundContactNormal;
        private bool m_Jump, m_PreviouslyGrounded, m_Jumping, m_IsGrounded;


        public Vector3 Velocity
        {
            get { return m_RigidBody.velocity; }
        }

        public bool Grounded
        {
            get { return m_IsGrounded; }
        }

        public bool Jumping
        {
            get { return m_Jumping; }
        }

        public bool Running
        {
            get
            {
 #if !MOBILE_INPUT
				return movementSettings.Running;
#else
	            return false;
#endif
            }
        }


        private void Start()
        {
            m_RigidBody = GetComponent<Rigidbody>();
            m_Capsule = GetComponent<CapsuleCollider>();
            mouseLook.Init (transform, cam.transform);
        }


        private void Update()
        {
            //控制视角转动到正常位置
            RotateView();
            //跳跃状态判断转移
            if (CrossPlatformInputManager.GetButtonDown("Jump") && !m_Jump)
            {
                m_Jump = true;
            }
        }

        //移动函数
        private void FixedUpdate()
        {
            //判断底部与地面的距离
            GroundCheck();
            //获得输入
            Vector2 input = GetInput();
            //如果检测到键盘有输入的话
            if ((Mathf.Abs(input.x) > float.Epsilon || Mathf.Abs(input.y) > float.Epsilon) && (advancedSettings.airControl || m_IsGrounded))
            {
                // always move along the camera forward as it is the direction that it being aimed at
                //始终沿着摄像机向前移动，因为它是瞄准的方向
                Vector3 desiredMove = cam.transform.forward*input.y + cam.transform.right*input.x;
                desiredMove = Vector3.ProjectOnPlane(desiredMove, m_GroundContactNormal).normalized;

                desiredMove.x = desiredMove.x*movementSettings.CurrentTargetSpeed;
                desiredMove.z = desiredMove.z*movementSettings.CurrentTargetSpeed;
                desiredMove.y = desiredMove.y*movementSettings.CurrentTargetSpeed;
                //判断刚体上面的速度向量的平方是否 小于 当前移动速度的平方
                if (m_RigidBody.velocity.sqrMagnitude <
                    (movementSettings.CurrentTargetSpeed*movementSettings.CurrentTargetSpeed))
                {
                    //给刚体添加一个向前的作用力
                    m_RigidBody.AddForce(desiredMove*SlopeMultiplier(), ForceMode.Impulse);
                }
            }
            //是否在地面上，判断跳跃
            if (m_IsGrounded)
            {
                m_RigidBody.drag = 5f;

                if (m_Jump)
                {
                    m_RigidBody.drag = 0f;
                    m_RigidBody.velocity = new Vector3(m_RigidBody.velocity.x, 0f, m_RigidBody.velocity.z);
                    m_RigidBody.AddForce(new Vector3(0f, movementSettings.JumpForce, 0f), ForceMode.Impulse);
                    m_Jumping = true;
                }

                if (!m_Jumping && Mathf.Abs(input.x) < float.Epsilon && Mathf.Abs(input.y) < float.Epsilon && m_RigidBody.velocity.magnitude < 1f)
                {
                    m_RigidBody.Sleep();
                }
            }
            else
            {
                m_RigidBody.drag = 0f;
                if (m_PreviouslyGrounded && !m_Jumping)
                {
                    StickToGroundHelper();
                }
            }
            m_Jump = false;
        }

        //斜率乘数
        private float SlopeMultiplier()
        {
            float angle = Vector3.Angle(m_GroundContactNormal, Vector3.up);
            return movementSettings.SlopeCurveModifier.Evaluate(angle);
        }

        //判断是否在地面上，不在地面上就落在地面上
        private void StickToGroundHelper()
        {
            RaycastHit hitInfo;
            if (Physics.SphereCast(transform.position, m_Capsule.radius, Vector3.down, out hitInfo,
                                   ((m_Capsule.height/2f) - m_Capsule.radius) +
                                   advancedSettings.stickToGroundHelperDistance))
            {
                if (Mathf.Abs(Vector3.Angle(hitInfo.normal, Vector3.up)) < 85f)
                {
                    m_RigidBody.velocity = Vector3.ProjectOnPlane(m_RigidBody.velocity, hitInfo.normal);
                }
            }
        }

        //检测键盘输入
        private Vector2 GetInput()
        {
            
            Vector2 input = new Vector2
                {
                    x = CrossPlatformInputManager.GetAxis("Horizontal"),
                    y = CrossPlatformInputManager.GetAxis("Vertical")
                };
			movementSettings.UpdateDesiredTargetSpeed(input);
            return input;
        }

        //视角移动
        private void RotateView()
        {
            //avoids the mouse looking if the game is effectively paused
            if (Mathf.Abs(Time.timeScale) < float.Epsilon) return;

            // get the rotation before it's changed
            float oldYRotation = transform.eulerAngles.y;

            mouseLook.LookRotation (transform, cam.transform);

            if (m_IsGrounded || advancedSettings.airControl)
            {
                // Rotate the rigidbody velocity to match the new direction that the character is looking
                Quaternion velRotation = Quaternion.AngleAxis(transform.eulerAngles.y - oldYRotation, Vector3.up);
                m_RigidBody.velocity = velRotation*m_RigidBody.velocity;
            }
        }


        /// sphere cast down just beyond the bottom of the capsule to see if the capsule is colliding round the bottom
        //球体在胶囊的底部被压下，看看胶囊是否在底部碰撞
        private void GroundCheck()
        {
            m_PreviouslyGrounded = m_IsGrounded;
            RaycastHit hitInfo;
            if (Physics.SphereCast(transform.position, m_Capsule.radius, Vector3.down, out hitInfo,
                                   ((m_Capsule.height/2f) - m_Capsule.radius) + advancedSettings.groundCheckDistance))
            {
                m_IsGrounded = true;
                m_GroundContactNormal = hitInfo.normal;
            }
            else
            {
                m_IsGrounded = false;
                m_GroundContactNormal = Vector3.up;
            }
            if (!m_PreviouslyGrounded && m_IsGrounded && m_Jumping)
            {
                m_Jumping = false;
            }
        }
    }
}

其中核心的人物角色移动代码：

m_RigidBody.AddForce(desiredMove*SlopeMultiplier(), ForceMode.Impulse);
desiredMove: 这个是获取到摄像机正前方 x 键盘输入 Vertical的值,摄像机右边 x 键盘输入 Horizontal的值
SlopeMuliplier: 是斜率乘数,说白了就是摩擦力 反作用力

ForceMode 作用力方式 枚举类型
（1）ForceMode.Force：默认方式，使用刚体的质量计算，以每帧间隔时间为单位计算动量。
（2）ForceMode.Acceleration：在此种作用方式下会忽略刚体的实际质量而采用默认值1.0f，时间间隔以系统帧频间隔计算（默认值为0.02s）
（3）ForceMode.Impulse：此种方式采用瞬间力作用方式，即把t的值默认为1，不再采用系统的帧频间隔
（4）ForceMode.VelocityChange：此种作用方式下将忽略刚体的实际质量，采用默认质量1.0，同时也忽略系统的实际帧频间隔，采用默认间隔1.0