Unity自动寻路Navmesh之跳跃、攀爬、斜坡
发表于2017-12-23
Navmesh作为Unity官方内置的寻路插件，下面我们就来给大家介绍下自动寻路插件Navmesh是怎么实现游戏中跳跃、攀爬、斜坡这几个功能的，具体步骤如下：
1.在场景中摆放各种模型，包括地板，斜坡，山体，扶梯等
2.为所有的模型加上Navigation Static和OffMeshLink Generatic(这个根据需要，例如地板与斜坡相连，斜坡就不需要添加OffMeshLink)
3.特殊处理扶梯，需要手动添加Off Mesh Link，设置好开始点和结束点
4.保存场景，烘焙场景
5.添加角色模型，为其加Nav Mesh Agent组件
6.为角色添加一个新脚本，AgentLocomotion.cs,用来处理自动寻路，已经角色动画变换。代码比较长，大家可以结合注释来理解
using UnityEngine;
using System.Collections;
public class AgentLocomotion : MonoBehaviour
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private Vector3 target;//目标位置
private NavMeshAgent agent;
private Animation anim;//动画
private string locoState = "Locomotion_Stand";
private Vector3 linkStart;//OffMeshLink的开始点
private Vector3 linkEnd;//OffMeshLink的结束点
private Quaternion linkRotate;//OffMeshLink的旋转
private bool begin;//是否开始寻路
// Use this for initialization
void Start()
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agent = GetComponent<NavMeshAgent>();
//自动移动并关闭OffMeshLinks,即在两个隔离障碍物直接生成的OffMeshLink，agent不会自动越过
agent.autoTraverseOffMeshLink = false;
//创建动画
AnimationSetup();
//起一个协程，处理动画状态机
StartCoroutine(AnimationStateMachine());
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void Update()
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//鼠标左键点击
if (Input.GetMouseButtonDown(0))
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//摄像机到点击位置的的射线
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit hit;
if (Physics.Raycast(ray, out hit))
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//判断点击的是否地形
if (hit.collider.tag.Equals("Obstacle"))
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begin = true;
//点击位置坐标
target = hit.point;
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//每一帧，设置目标点
if (begin)
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agent.SetDestination(target);
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IEnumerator AnimationStateMachine()
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//根据locoState不同的状态来处理，调用相关的函数
while (Application.isPlaying)
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yield return StartCoroutine(locoState);
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//站立
IEnumerator Locomotion_Stand()
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do
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UpdateAnimationBlend();
yield return new WaitForSeconds(0);
｝ while (agent.remainingDistance == 0);
//未到达目标点，转到下一个状态Locomotion_Move
locoState = "Locomotion_Move";
yield return null;
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IEnumerator Locomotion_Move()
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do
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UpdateAnimationBlend();
yield return new WaitForSeconds(0);
//角色处于OffMeshLink，根据不同的地点，选择不同动画
if (agent.isOnOffMeshLink)
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locoState = SelectLinkAnimation();
return (true);
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｝ while (agent.remainingDistance != 0);
//已经到达目标点，状态转为Stand
locoState = "Locomotion_Stand";
yield return null;
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IEnumerator Locomotion_Jump()
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//播放跳跃动画
string linkAnim = "RunJump";
Vector3 posStart = transform.position;
agent.Stop(true);
anim.CrossFade(linkAnim, 0.1f, PlayMode.StopAll);
transform.rotation = linkRotate;
do
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//计算新的位置
float tlerp = anim[linkAnim].normalizedTime;
Vector3 newPos = Vector3.Lerp(posStart, linkEnd, tlerp);
newPos.y += 0.4f * Mathf.Sin(3.14159f * tlerp);
transform.position = newPos;
yield return new WaitForSeconds(0);
｝ while (anim[linkAnim].normalizedTime < 1);
//动画恢复到Idle
anim.Play("Idle");
agent.CompleteOffMeshLink();
agent.Resume();
//下一个状态为Stand
transform.position = linkEnd;
locoState = "Locomotion_Stand";
yield return null;
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//梯子
IEnumerator Locomotion_Ladder()
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//梯子的中心位置
Vector3 linkCenter = (linkStart + linkEnd) * 0.5f;
string linkAnim;
//判断是在梯子上还是梯子下
if (transform.position.y > linkCenter.y)
linkAnim = "Ladder Down";
else
linkAnim = "Ladder Up";
agent.Stop(true);
Quaternion startRot = transform.rotation;
Vector3 startPos = transform.position;
float blendTime = 0.2f;
float tblend = 0f;
//角色的位置插值变化（0.2内变化）
do
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transform.position = Vector3.Lerp(startPos, linkStart, tblend / blendTime);
transform.rotation = Quaternion.Lerp(startRot, linkRotate, tblend / blendTime);
yield return new WaitForSeconds(0);
tblend += Time.deltaTime;
｝ while (tblend < blendTime);
//设置位置
transform.position = linkStart;
//播放动画
anim.CrossFade(linkAnim, 0.1f, PlayMode.StopAll);
agent.ActivateCurrentOffMeshLink(false);
//等待动画结束
do
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yield return new WaitForSeconds(0);
｝ while (anim[linkAnim].normalizedTime < 1);
agent.ActivateCurrentOffMeshLink(true);
//恢复Idle状态
anim.Play("Idle");
transform.position = linkEnd;
agent.CompleteOffMeshLink();
agent.Resume();
//下一个状态Stand
locoState = "Locomotion_Stand";
yield return null;
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private string SelectLinkAnimation()
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//获得当前的OffMeshLink数据
OffMeshLinkData link = agent.currentOffMeshLinkData;
//计算角色当前是在link的开始点还是结束点（因为OffMeshLink是双向的）
float distS = (transform.position - link.startPos).magnitude;
float distE = (transform.position - link.endPos).magnitude;
if (distS < distE)
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linkStart = link.startPos;
linkEnd = link.endPos;
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else
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linkStart = link.endPos;
linkEnd = link.startPos;
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//OffMeshLink的方向
Vector3 alignDir = linkEnd - linkStart;
//忽略y轴
alignDir.y = 0;
//计算旋转角度
linkRotate = Quaternion.LookRotation(alignDir);
//判断OffMeshLink是手动的（楼梯）还是自动生成的（跳跃）
if (link.linkType == OffMeshLinkType.LinkTypeManual)
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return ("Locomotion_Ladder");
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else
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return ("Locomotion_Jump");
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private void AnimationSetup()
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anim = GetComponent<Animation>();
// 把walk和run动画放到同一层，然后同步他们的速度。
anim["Walk"].layer = 1;
anim["Run"].layer = 1;
anim.SyncLayer(1);
//设置“跳跃”，“爬楼梯”，“下楼梯”的动画模式和速度
anim["RunJump"].wrapMode = WrapMode.ClampForever;
anim["RunJump"].speed = 2;
anim["Ladder Up"].wrapMode = WrapMode.ClampForever;
anim["Ladder Up"].speed = 2;
anim["Ladder Down"].wrapMode = WrapMode.ClampForever;
anim["Ladder Down"].speed = 2;
//初始化动画状态为Idle
anim.CrossFade("Idle", 0.1f, PlayMode.StopAll);
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//更新动画融合
private void UpdateAnimationBlend()
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//行走速度
float walkAnimationSpeed = 1.5f;
//奔跑速度
float runAnimationSpeed = 4.0f;
//速度阀值（idle和walk的临界点）
float speedThreshold = 0.1f;
//速度，只考虑x和z
Vector3 velocityXZ = new Vector3(agent.velocity.x, 0.0f, agent.velocity.z);
//速度值
float speed = velocityXZ.magnitude;
//设置Run动画的速度
anim["Run"].speed = speed / runAnimationSpeed;
//设置Walk动画的速度
anim["Walk"].speed = speed / walkAnimationSpeed;
//根据agent的速度大小，确定animation的播放状态
if (speed > (walkAnimationSpeed + runAnimationSpeed) / 2)
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anim.CrossFade("Run");
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else if (speed > speedThreshold)
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anim.CrossFade("Walk");
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else
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anim.CrossFade("Idle", 0.1f, PlayMode.StopAll);
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总结
今天的这个例子比较复杂，要根据寻路网格的类型，来处理角色的动作是普通寻路，还是攀爬，抑或跳跃。这个例子应该是比较接近真实项目了。大家在实际项目中如果还有更加复杂的寻路，欢迎探讨。