Unity3D 實現怪物巡邏、按路線行走操作

為了豐富我們的遊戲，我們經常會給遊戲中的角色（怪物）新增行走路線，本想用 ITweenPath 外掛實現，但是一直沒有找到合適的辦法，因為不知道如何實現實行的獲得地形高度，或者如果使用角色控制器移動（CharacterController），怎麼使用 ITweenPath 驅動？本人愚笨，自己實現了個（這兒只是使用 ITweenPath 繪製出來的點），也算拋磚引玉，如果讀者知道如何更簡單的實現方式，還請告之！共同進步！

先來看看最終的效果圖：

場景中有兩個角色，然後他們會在 ITweenPath 繪製的線上隨機移動！下面我們先搭建好測試的場景，如下圖：

然後我們使用 ITweenEditor 編輯場景中角色的行進路線，如下圖：

後面，就需要我們自己去實現行走的邏輯了，獲取 ITweenPath 曲線上的點，前面的文章中提到，詳細可以看此連結，然後我們新建立一個 RoleController.cs 檔案，然後編寫我們的程式碼，全部程式碼如下：

using UnityEngine;
using System.Collections;

public class RoleController : MonoBehaviour 
{
	public iTweenPath tweenPath;

	/// <summary>
	/// 曲線上面點的個數，點數越多移動越平滑
	/// </summary>
	public int pointSize = 5;

	/// <summary>
	/// 角色移動速度
	/// </summary>
	public float speed = 3f;

	public AnimationClip walkClip;
	public AnimationClip idleClip;

	private Vector3[] pathPositionList;
	private Vector3 pathPoint;

	private Vector3[] positionList;
	private Vector3 nextPoint;
	private Vector3 direction;

	private int moveIndex;
	private bool moveStatus;
	private bool idleStatus;

	private Animation animation;

	void Awake()
	{
		this.pathPositionList = PointController.PointList(tweenPath.nodes.ToArray(), this.pointSize);
		this.animation = this.GetComponent<Animation> ();

		this.moveIndex = 0;
		this.moveStatus = false;
		this.idleStatus = false;

		if (this.pathPositionList.Length > 0) 
		{
			this.pathPoint = this.pathPositionList [Random.Range(0, this.pathPositionList.Length)];
		}
	}

	void Start()
	{
		this.transform.position = this.GetTerrainPosition (this.pathPoint);
		this.StartCoroutine(this.SetNextPositionList(0));
	}

	void Update()
	{
		this.SetMoveDirection ();
		this.SetMovePosition ();
	}

	/// <summary>
	/// 設定移動向量
	/// </summary>
	protected void SetMoveDirection()
	{
		if (this.positionList == null) return;
		if (this.moveIndex < this.positionList.Length) 
		{
			if(!this.moveStatus)
			{
				this.pathPoint = this.positionList[this.moveIndex];
				this.nextPoint = this.GetTerrainPosition(this.pathPoint);
				this.direction = (this.nextPoint - this.transform.position).normalized * this.speed;

				if(this.direction != Vector3.zero)
				{
					this.transform.rotation = Quaternion.LookRotation(new Vector3(this.direction.x, 0f, this.direction.z));
					this.moveStatus = true;
				}else{
					this.moveIndex ++;
				}
			}
		}else
		{
			if(!idleStatus)
			{
				this.idleStatus = true;
				this.animation.CrossFade (this.idleClip.name);
				this.StartCoroutine(this.SetNextPositionList(5));
			}
		}
	}

	/// <summary>
	/// 設定移動位置
	/// </summary>
	protected void SetMovePosition ()
	{
		if (this.positionList == null) return;

		if (!this.IsArrivePosition ()) 
		{
			//this.characterController.Move(this.direction * Time.deltaTime); // 可以取消這句，並且註釋下面那句，可以使用角色控制器進行移動
			this.transform.position = GetTerrainPosition(this.transform.position + this.direction * Time.deltaTime);
		} else {
			this.transform.position = this.nextPoint;
			this.moveStatus = false;
			this.moveIndex ++;
		}
	}

	protected IEnumerator SetNextPositionList(int sceond)
	{
		if (sceond > 0) 
		{
			yield return new WaitForSeconds (5);
		} else {
			yield return null;
		}

		int index = this.GetIndexByList (this.pathPositionList, this.pathPoint);
		if (index != -1) 
		{
			int nextIndex = Random.Range(0, this.pathPositionList.Length);
			if(index != nextIndex)
			{
				int beginIndex = index > nextIndex ? nextIndex : index;
				int endIndex = index > nextIndex ? index : nextIndex;

				Vector3[] positionList = new Vector3[endIndex - beginIndex];
				int positionLength = positionList.Length;

				if(index > nextIndex)
				{
					for(int pathIndex = endIndex, positionIndex = 0; pathIndex >= beginIndex && positionIndex < positionLength; pathIndex --, positionIndex ++)
					{
						positionList[positionIndex] = this.pathPositionList[pathIndex];
					}
				}else{
					for(int pathIndex = beginIndex, positionIndex = 0; pathIndex <= endIndex && positionIndex < positionLength; pathIndex ++, positionIndex ++)
					{
						positionList[positionIndex] = this.pathPositionList[pathIndex];
					}
				}

				this.moveIndex = 0;
				this.moveStatus = false;
				this.idleStatus = false;
				this.animation.CrossFade (this.walkClip.name);

				this.positionList = positionList;
			}
		}
	}

	/// <summary>
	/// 獲取點帖地位置
	/// </summary>
	/// <returns>The terrion position.</returns>
	/// <param name="position">Position.</param>
	private Vector3 GetTerrainPosition(Vector3 position)
	{
		Vector3 terrainPosition = new Vector3 (position.x, position.y, position.z);
		terrainPosition.y = Terrain.activeTerrain.SampleHeight (terrainPosition);
		return terrainPosition;
	}

	/// <summary>
	/// 是否到達指定位置
	/// </summary>
	/// <returns><c>true</c> if this instance is arrive position; otherwise, <c>false</c>.</returns>
	private bool IsArrivePosition()
	{
		Vector3 currentDirection = (this.nextPoint - (this.transform.position + this.direction * Time.deltaTime)).normalized;
		if (this.CalculateNormalized (currentDirection) == this.CalculateNormalized (this.direction) * -1) 
		{
			return true;
		}
		return false;
	}

	/// <summary>
	/// 計算向量標準
	/// </summary>
	/// <returns>The normalized.</returns>
	/// <param name="data">Data.</param>
	private Vector3 CalculateNormalized(Vector3 data)
	{
		Vector3 position = Vector3.zero;
		position.x = data.x >= 0 ? 1 : -1;
		position.z = data.z >= 0 ? 1 : -1;
		return position;
	}

	private int GetIndexByList(Vector3[] positionList, Vector3 position)
	{
		int index = 0;
		foreach (Vector3 item in positionList) 
		{
			if(item.x == position.x && item.y == position.y && item.z == position.z) return index;
			index ++;
		}
		return -1;
	}
}

然後我們給場景中的角色掛載 RoleController.cs 指令碼，並且設定好相關屬性，如下圖：

最後執行遊戲，就可以看到角色在場景中按線路行走了！