Unity3D-利用FSM设计相机跟随实现.doc

Unity3D 利用FSM设计相机跟随实现FSM有限状态机前面已经跟读者介绍过，使用Unity3D引擎实现了动作状态以及技能切换，FSM使用的条件是有限个状态切换，我们可以将FSM应用到相机中，很多人会问在相机中如何使用FSM，不论那种架构其主要目的是将模块之间的耦合性降低，传统的写法就是使用一个相机跟随类，所有的逻辑一股脑的写在一个类或者两个类中，这样一旦逻辑变动，修改起来非常麻烦，可能修改的就不是一个类两个类的事情，而如果我们采用FSM设计相机跟随，这样就容易多了。接下来就实现FSM有限状态机，FSM作为一个通用类需要将其设置成模版的方式，具体代码如下所示：csharp view plain copy 在CODE上查看代码片派生到我的代码片using System; using System.Collections.Generic; namespace Core public class FSM public class Object where T : Object public delegate void Function(T self, float time); #region Protected members protected TimeSource timeSource = null; protected DictionaryK, State states = new DictionaryK,State(); protected State state = null; protected State prevState = null; #endregion #region Ctors public Object() timeSource = TimeManager.Instance.MasterSource; public Object(TimeSource source) timeSource = source; #endregion #region Public properties public K PrevState get return prevState.key; public K State get return state.key; set prevState = state; if (prevState != null) prevState.onExit(this as T, timeSource.TotalTime); State nextState; if (states.TryGetValue(value, out nextState) state = nextState; state.onEnter(this as T, timeSource.TotalTime); else state = null; public TimeSource TimeSource get return timeSource; set timeSource = value; #endregion #region Public methods public void AddState(K key, Function onEnter, Function onExec, Function onExit) State newState = new State(); newState.key = key; newState.onEnter = onEnter; newState.onExec = onExec; newState.onExit = onExit; states.Add(key, newState); public void Update() if (null = state) return; state.onExec(this as T, timeSource.TotalTime); #endregion public class State where T : Object public K key; public Object.Function onEnter; public Object.Function onExec; public Object.Function onExit; 在这个类中有三部分最重要，第一部分是定义了状态类，它实现了状态的切换函数，onEnter，onExec，onExit，这个是作为状态切换使用的。代码如下：csharp view plain copy 在CODE上查看代码片派生到我的代码片public class State where T : Object public K key; public Object.Function onEnter; public Object.Function onExec; public Object.Function onExit; 另一个类的函数是增加状态函数，这个需要在Start函数中去执行的，函数代码如下所示：csharp view plain copy 在CODE上查看代码片派生到我的代码片public void AddState(K key, Function onEnter, Function onExec, Function onExit) State newState = new State(); newState.key = key; newState.onEnter = onEnter; newState.onExec = onExec; newState.onExit = onExit; states.Add(key, newState); 最后一个函数就是Update函数，需要每帧去检测执行状态，函数如下所示：csharp view plain copy 在CODE上查看代码片派生到我的代码片public void Update() if (null = state) return; state.onExec(this as T, timeSource.TotalTime); 这三个是最重要的，必须要有的，接下来编写挂接到对象上的类FiniteStateMachine类脚本，代码如下所示：csharp view plain copy 在CODE上查看代码片派生到我的代码片using Sstem; using System.Collections.Generic; using UnityEngine; using Core; public class FiniteStateMachine : MonoBehaviour public enum UpdateFunction Update = 0, LateUpdate, FixedUpdate #region Public classes public class FSMObject : FSM.Object public GameObject go; public FSMObject(GameObject _go) go = _go; Serializable public class StateType public int id; public string onEnterMessage; public string onExecMessage; public string onExitMessage; public void onEnter(FSMObject fsmObject, float time) fsmObject.go.SendMessage(onEnterMessage, time, SendMessageOptions.RequireReceiver); public void onExec(FSMObject fsmObject, float time) fsmObject.go.SendMessage(onExecMessage, time, SendMessageOptions.RequireReceiver); public void onExit(FSMObject fsmObject, float time) fsmObject.go.SendMessage(onExitMessage, time, SendMessageOptions.RequireReceiver); #endregion #region Public members public bool manualUpdate = false; public UpdateFunction updateFunction = UpdateFunction.Update; public StateType states; public int startState; #endregion #region Protected members protected FSMObject fsmObject = null; #endregion #region Public properties public int PrevState get return fsmObject.PrevState; public int State get return fsmObject.State; set fsmObject.State = value; public TimeSource TimeSource get return fsmObject.TimeSource; set fsmObject.TimeSource = value; #endregion #region Public methods public void ForceUpdate() fsmObject.Update(); #endregion #region Unity callbacks protected void Start() fsmObject = new FSMObject(gameObject); foreach (StateType state in states) fsmObject.AddState(state.id, state.onEnter, state.onExec, state.onExit); fsmObject.State = startState; void Update() /Debug.Log (update); if (manualUpdate) return; if (UpdateFunction.Update = updateFunction) fsmObject.Update(); void LateUpdate() if (manualUpdate) return; if (UpdateFunction.LateUpdate = updateFunction) fsmObject.Update(); void FixedUpdate() if (manualUpdate) return; if (UpdateFunction.FixedUpdate = updateFunction) fsmObject.Update(); #endregion 该函数需要挂接到对象上，效果如下所示：以上就是我们所封装的FSM有限状态机，接下来在项目中使用我们的FSM，先实现最基本的逻辑类如下所示：csharp view plain copy 在CODE上查看代码片派生到我的代码片using System; using System.Collections.Generic; using UnityEngine; public class FollowCharacter : MonoBehaviour public GameObject player; public Vector3 sourceOffset = new Vector3(0.0f, 2.5f, -3.4f); public Vector3 targetOffset = new Vector3(0.0f, 1.7f, 0.0f); protected bool firstFrame; protected float currHeightSmoothing; protected float groundHeightTest; protected bool slideshowActive = false; protected float slideshowEnterTime = 0.0f; protected float slideshowExitTime = 0.0f; protected bool oldCameraActive = true; protected float oldFov = 70.0f; protected Vector3 oldCamSourceOffset = new Vector3(0.0f, 8.5f, -4.5f); protected Vector3 oldCamTargetOffset = new Vector3(0.0f, 0.9f, 5.3f); protected int cameraIndex = 3; protected float cameraFovs = 55.0f, 60.0f, 55.0f ; protected Vector3 cameraSourceOffsets = new Vector3(0.0f, 5.8f, -3.8f), new Vector3(0.0f, 6.04f, -4.0f), new Vector3(0.0f, 8.5f, -6.7f) ; protected Vector3 cameraTargetOffsets = new Vector3(0.0f, 2.2f, 2.5f), new Vector3(0.0f, 1.35f, 3.36f), new Vector3(0.0f, 1.45f, 5.3f) ; protected Vector3 newCamSourceOffset = new Vector3(0.0f, 6.04f, -4.0f);/Camera 2 protected Vector3 newCamTargetOffset = new Vector3(0.0f, 1.35f, 3.36f);/Camera 2 protected Vector3 testNewTurboSourceOffset = new Vector3(0.0f, 5.8f, -4.0f); protected Vector3 testNewTurboTargetOffset = new Vector3(0.0f, 2.1f, 2.5f); protected Vector3 testNewFinalSourceOffset = new Vector3(-6.5f, 5.0f, -5.5f); protected Vector3 testNewFinalTargetOffset = new Vector3(-4.5f, 1.7f, 0.0f); csharp view plain copy 在CODE上查看代码片派生到我的代码片 #region public Classes public class ShakeData public float duration; public float noise; public float smoothTime; public ShakeData(float _duration, float _noise, float _smoothTime) duration = _duration; noise = _noise; smoothTime = _smoothTime; #endregion public void OnFollowCharaEnter(float time) prevPlayerPivot = player.transform.position; firstFrame = rue; currHeightSmoothing = heightSmoothing; deadTime = -1.0f; actionTaken = false; public void OnFollowCharaExec(float time) if (player = null) return; float dt = Time.fixedDeltaTime; float now = TimeManager.Instance.MasterSource.TotalTime; Vector3 playerPivot = player.transform.position; playerPivot.x = 0.0f; playerPivot.y = 0.0f; float targetHeight = playerPivot.y; if (firstFrame) lastPivotHeight = targetHeight; prevPlayerPivot = playerPivot; heightVelocity = 0.0f; firstFrame = false; else float targetSmoothTime = 0.1f; smoothTime = Mathf.MoveTowards(smoothTime, targetSmoothTime, 2.5f * dt); lastPivotHeight = Mathf.SmoothDamp(lastPivotHeight, targetHeight, ref heightVelocity, smoothTime, 50.0f, dt); prevPlayerPivot = playerPivot; Vector3 camPivot = new Vector3(prevPlayerPivot.x * 0.8f, lastPivotHeight, prevPlayerPivot.z); lastSourceOffset = this.EaseTo(lastSourceOffset, goalSourceOffset, sourceOffset); lastTargetOffset = this.EaseTo(lastTargetOffset, goalTargetOffset, targetOffset); transform.position = camPivot + lastSourceOffset + offset * 0.1f + noise * noiseStrength; / +noise * noiseStrength + noiseTremor * 0.00069f * kinematics.PlayerRigidbody.velocity.z; /PIETRO transform.LookAt(camPivot + lastTargetOffset + offset * 0.1f, Vector3.up); if (!TimeManager.Instance.MasterSource.IsPaused) /Camera Shake if (shakeCameraActive) ShakeCamera(dt); /tremor (always active this.UpdateTremor(dt); /check if is dead if (now - deadTime 3.6f & !actionTaken & deadTime 0.0f) actionTaken = true; /Debug.Log(GO TO REWARD); LevelRoot.Instance.BroadcastMessage(GoToOffgame); /GoToReward); public void OnFollowCharaExit(float time) void OnReset() /Debug.Log(RESET CAM); interpolating = false; shakeCameraActive = false; sourceOffset = defaultSourceOffset; targetOffset = defaultTargetOffset; void ShakeCamera(float deltaTime) if (TimeManager.Instance.MasterSource.TotalTime - shakeStartTime 0.0f) noiseStrength = Mathf.SmoothDamp(noiseStrength, currentShakeData.noise, ref noiseStrengthVel, currentShakeData.smoothTime, 300.0f, deltaTime); else noiseStrength = currentShakeData.noise; / go directly if (noiseStrength 0.0f) Vector3 v = UnityEngine.Random.onUnitSphere; noise += (v - noise) * deltaTime * 8.0f; else noise = SRVector3.zero; if (TimeManager.Instance.MasterSource.TotalTime - shakeStartTime = currentShakeData.duration) StopShakeCamera(); void StopShakeCam