Unity物体运动之物体按规定路线运动的优化。本节针对之前已有的《Unity物体运动之物体按规定路线运动的使用》（链接如下）的不足，物体运动朝向不对的问题，进行优化的简单案例，具体如下
工具/原料
Unity
一、知识要点
1、Vector3.MoveTowards：1）功能简述publicstatic外狒芙梨Vector3MoveTowards(Vector3current,Vector3target,惺绅寨瞀floatmaxDistanceDelta);Movesapointcurrentinastraightlinetowardsatargetpoint.ThevaluereturnedbythisfunctionisapointmaxDistanceDeltaunitsclosertoatarget/pointalongalinebetweencurrentandtarget.IfthetargetiscloserthanmaxDistanceDelta/thenthereturnedvaluewillbeequaltotarget(ie,themovementwillnotovershootthetarget).NegativevaluesofmaxDistanceDeltacanbeusedtopushthepointawayfromthetarget.2）使用举例usingUnityEngine;usingSystem.Collections;publicclassExampleClass:MonoBehaviour{publicTransformtarget;publicfloatspeed;voidUpdate(){floatstep=speed*Time.deltaTime;transform.position=Vector3.MoveTowards(transform.position,target.position,step);}}
2、Transform.LookAt：1）功能简述publicvoidLoo氯短赤亻kAt(Transformtarget,Vec墉掠载牿tor3worldUp=Vector3.up);Parameterstarget：Objecttopointtowards.worldUp：Vectorspecifyingtheupwarddirection.Rotatesthetransformsotheforwardvectorpointsat/target/'scurrentposition.ThenitrotatesthetransformtopointitsupdirectionvectorinthedirectionhintedatbytheworldUpvector.IfyouleaveouttheworldUpparameter,thefunctionwillusetheworldyaxis.worldUpisonlyahintvector.TheupvectoroftherotationwillonlymatchtheworldUpvectoriftheforwarddirectionisperpendiculartoworldUp.2）使用举例//Thiscompletescriptcanbeattachedtoacameratomakeit//continuouslypointatanotherobject.//Thetargetvariableshowsupasapropertyintheinspector.//Draganotherobjectontoittomakethecameralookatit.usingUnityEngine;usingSystem.Collections;publicclassExampleClass:MonoBehaviour{publicTransformtarget;voidUpdate() {//Rotatethecameraeveryframesoitkeepslookingatthetargettransform.LookAt(target);}}
二、物体运动之物体按规定路线运动的优化
1、在Unity场景中新建一个“Plane”和“Cube”是低昂调整大小与布局，“MaainCamera”的视角调整好，具体如下图
2、在场景中添加路线的关键点，演示需要大致随意摆放几个点，具体如下图
3、在工程中，仙剑两个脚本“Move”和“WayPoints”，代开脚本进行编辑，具体如下图
4、在“WayPoints”脚本上编辑代码，具体代码和代码说明如下图
5、“WayPoints”脚本具体内容如下：usingUnityEngine;publicclassWayPoints:MonoBehaviour{publicstaticTransform[]wayPoints;voidAwake(){intcount=transform.childCount;wayPoints=newTransform[count];for(inti=0;i<count;i++){wayPoints[i]=transform.GetChild(i);}}}
6、在“Move”脚本上编辑代码，本脚本关键使用LookAt朝向目标，然后MoveTowards在移动到目标点，具体代码和代码说明如下图
7、“Move”脚本具体内容如蛴蛩钔淞下：usingUnityEngine;publicclassMove:MonoBeh锾攒揉敫aviour{publicfloatspeed=5;privateTransform[]ways;privateintindex;//UsethisforinitializationvoidStart(){ways=WayPoints.wayPoints;index=0;}//UpdateiscalledonceperframevoidUpdate(){MoveTo();}voidMoveTo(){if(index>ways.Length-1)return;//保证正面朝向物体运动transform.LookAt(ways[index].position);transform.position=Vector3.MoveTowards(transform.position,ways[index].position,Time.deltaTime*speed);if(Vector3.Distance(ways[index].position,transform.position)<0.2f){index++;if(index==ways.Length){transform.position=ways[index-1].position;}}}}
8、脚本编译正确，回到Unity界面，“WayPoints”脚本赋给场景中的“WayPoints”，“Move”脚本赋给“Cube”
9、运行场景，可以看到，物体首先朝向目标点，然后在向目标点运动，弥补朝向不变的不足，具体如下图
10、到此，《Unity物体运动之物体按规定路线运动的优化》讲解结束，谢谢