unity3d的动力学汽车脚本

她。 3D打印店铺

这是从官网论坛上收集的一个汽车脚本，经过验证可以使用。由于skidmarks这个配套的脚本没有找到，所以把skidmarks相关的语句都屏蔽了，所以很遗憾没有刹车印的效果，其他的没有改。
    拿出来共享，感兴趣的一起研究下。
    汽车脚本代码看起来都比较复杂，主要是老外的编程底子牛，什么都写到代码里自动生成了。其实有些东西可以在编辑器里完成，这样就省不少代码了。还有制动和变速箱部分用了不少代码，这个可能要点汽车发动机知识，反正我是一点都没看懂。
    不想研究的可以直接拿来用。
    使用方法如下：
    1、把脚本直接连到汽车车身网格上，车身要有Rigidbody Component，要有四个轮子网格做子物体。 要想有声音的话还要有AudioSource Component。
    2、打开Inspector，选择汽车脚本，把四个轮子连接到相对应的Transform参数上。设置wheelRadius参数为你轮子网格的大小。WheelCollider是自动生成的，所以无需手动添加。这样就能保证运行了，其他的声音和灰尘可以再添加。
    脚本源代码如下：
#pragma strict
//maximal corner and braking acceleration capabilities

var maxCornerAccel=10.0;

var maxBrakeAccel=10.0;
//center of gravity height - effects tilting in corners

var cogY = 0.0;
//engine powerband

var minRPM = 700;

var maxRPM = 6000;
//maximum Engine Torque

var maxTorque = 400;
//automatic transmission shift points

var shiftDownRPM = 2500;

var shiftUpRPM = 5500;
//gear ratios

var gearRatios = [-2.66, 2.66, 1.78, 1.30, 1.00];

var finalDriveRatio = 3.4;
//a basic handling modifier:

//1.0 understeer

//0.0 oversteer

var handlingTendency = 0.7;
//graphical wheel objects

var wheelFR : Transform;

var wheelFL : Transform;

var wheelBR : Transform;

var wheelBL : Transform;
//suspension setup

var suspensionDistance = 0.3;

var springs = 1000;

var dampers = 200;

var wheelRadius = 0.45;
//particle effect for ground dust

var groundDustEffect : Transform;
private var queryUserInput = true;

private var engineRPM : float;

private var steerVelo = 0.0;

private var brake = 0.0;

private var handbrake = 0.0;

private var steer = 0.0;

private var motor = 0.0;

//private var skidTime = 0.0;

private var onGround = false;

private var cornerSlip = 0.0;

private var driveSlip = 0.0;

private var wheelRPM : float;

private var gear = 1;

//private var skidmarks : Skidmarks;

private var wheels : WheelData[];

private var wheelY = 0.0;

private var rev = 0.0;
//Functions to be used by external scripts

//controlling the car if required

//===================================================================
//return a status string for the vehicle

function GetStatus(gui : GUIText) {

   gui.text="v="+(rigidbody.velocity.magnitude * 3.6).ToString("f1") + " km/h
gear= "+gear+"
rpm= "+engineRPM.ToString("f0");

}
//return an information string for the vehicle

function GetControlString(gui : GUIText) {

   gui.text="Use arrow keys to control the jeep,
space for handbrake.";

}
//Enable or disable user controls

function SetEnableUserInput(enableInput)

{

   queryUserInput=enableInput;

}
//Car physics

//===================================================================
//some whee calculation data

class WheelData{

   var rotation = 0.0;

   var coll : WheelCollider;

   var graphic : Transform;

   var maxSteerAngle = 0.0;

   var lastSkidMark = -1;

   var powered = false;

   var handbraked = false;

   var originalRotation : Quaternion;

};
function Start () {

   //setup wheels

   wheels=new WheelData[4];

   for(i=0;i<4;i++)

      wheels = new WheelData();

      

   wheels[0].graphic = wheelFL;

   wheels[1].graphic = wheelFR;

   wheels[2].graphic = wheelBL;

   wheels[3].graphic = wheelBR;
   wheels[0].maxSteerAngle=30.0;

   wheels[1].maxSteerAngle=30.0;

   wheels[2].powered=true;

   wheels[3].powered=true;

   wheels[2].handbraked=true;

   wheels[3].handbraked=true;
   for(w in wheels)

   {

      if(w.graphic==null)

         Debug.Log("You need to assign all four wheels for the car script!");

      if(!w.graphic.transform.IsChildOf(transform))   

         Debug.Log("Wheels need to be children of the Object with the car script");

         

      w.originalRotation = w.graphic.localRotation;
      //create collider

      colliderObject = new GameObject("WheelCollider");

      colliderObject.transform.parent = transform;

      colliderObject.transform.position = w.graphic.position;

      w.coll = colliderObject.AddComponent(WheelCollider);

      w.coll.suspensionDistance = suspensionDistance;

      w.coll.suspensionSpring.spring = springs;

      w.coll.suspensionSpring.damper = dampers;

      //no grip, as we simulate handling ourselves

      w.coll.forwardFriction.stiffness = 0;

      w.coll.sidewaysFriction.stiffness = 0;

      w.coll.radius = wheelRadius;

   }  
   //get wheel height (height forces are applied on)

   wheelY=wheels[0].graphic.localPosition.y;

   

   //setup center of gravity

   rigidbody.centerOfMass.y = cogY;

   

   //find skidmark object

//   skidmarks = FindObjectOfType(typeof(Skidmarks));

   

   //shift to first

   gear=1;

}
//update wheel status

function UpdateWheels()

{

   //calculate handbrake slip for traction gfx

    handbrakeSlip=handbrake*rigidbody.velocity.magnitude*0.1;

   if(handbrakeSlip>1)

      handbrakeSlip=1;

      

   totalSlip=0.0;

   onGround=false;

   for(w in wheels)

   {      

      //rotate wheel

      w.rotation += wheelRPM / 60.0 * -rev * 360.0 * Time.fixedDeltaTime;

      w.rotation = Mathf.Repeat(w.rotation, 360.0);      

      w.graphic.localRotation= Quaternion.Euler( w.rotation, w.maxSteerAngle*steer, 0.0 ) * w.originalRotation;
      //check if wheel is on ground

      if(w.coll.isGrounded)

         onGround=true;

         

      slip = cornerSlip+(w.powered?driveSlip:0.0)+(w.handbraked?handbrakeSlip:0.0);

      totalSlip += slip;

      

      var hit : WheelHit;

      var c : WheelCollider;

      c = w.coll;

      if(c.GetGroundHit(hit))

      {

         //if the wheel touches the ground, adjust graphical wheel position to reflect springs

         w.graphic.localPosition.y-=Vector3.Dot(w.graphic.position-hit.point,transform.up)-w.coll.radius;

         

         //create dust on ground if appropiate

         if(slip>0.5 && hit.collider.tag=="Dusty")

         {

            groundDustEffect.position=hit.point;

            groundDustEffect.particleEmitter.worldVelocity=rigidbody.velocity*0.5;

            groundDustEffect.particleEmitter.minEmission=(slip-0.5)*3;

            groundDustEffect.particleEmitter.maxEmission=(slip-0.5)*3;

            groundDustEffect.particleEmitter.Emit();                        

         }

         

         //and skid marks            

         /*if(slip>0.75 && skidmarks != null)

            w.lastSkidMark=skidmarks.AddSkidMark(hit.point,hit.normal,(slip-0.75)*2,w.lastSkidMark);

         else

            w.lastSkidMark=-1; */

      }

     // else w.lastSkidMark=-1;

   }

   totalSlip/=wheels.length;

}
//Automatically shift gears

function AutomaticTransmission()

{

   if(gear>0)

   {

      if(engineRPM>shiftUpRPM&&gear<gearRatios.length-1)

         gear++;

      if(engineRPM<shiftDownRPM&&gear>1)

         gear--;

   }
}
//Calculate engine acceleration force for current RPM and trottle

function CalcEngine() : float

{

   //no engine when braking

   if(brake+handbrake>0.1)

      motor=0.0;

   

   //if car is airborne, just rev engine

   if(!onGround)

   {

      engineRPM += (motor-0.3)*25000.0*Time.deltaTime;

      engineRPM = Mathf.Clamp(engineRPM,minRPM,maxRPM);

      return 0.0;

   }

   else

   {

      AutomaticTransmission();

      engineRPM=wheelRPM*gearRatios[gear]*finalDriveRatio;

      if(engineRPM<minRPM)

         engineRPM=minRPM;

      if(engineRPM<maxRPM)

      {

         //fake a basic torque curve

         x = (2*(engineRPM/maxRPM)-1);

         torqueCurve = 0.5*(-x*x+2);

         torqueToForceRatio = gearRatios[gear]*finalDriveRatio/wheelRadius;

         return motor*maxTorque*torqueCurve*torqueToForceRatio;

      }

      else

         //rpm delimiter

         return 0.0;

   }

}
//Car physics

//The physics of this car are really a trial-and-error based extension of

//basic "Asteriods" physics -- so you will get a pretty arcade-like feel.

//This may or may not be what you want, for a more physical approach research

//the wheel colliders

function HandlePhysics () {

   var velo=rigidbody.velocity;

   wheelRPM=velo.magnitude*60.0*0.5;
   rigidbody.angularVelocity=new Vector3(rigidbody.angularVelocity.x,0.0,rigidbody.angularVelocity.z);

   dir=transform.TransformDirection(Vector3.forward);

   flatDir=Vector3.Normalize(new Vector3(dir.x,0,dir.z));

   flatVelo=new Vector3(velo.x,0,velo.z);

   rev=Mathf.Sign(Vector3.Dot(flatVelo,flatDir));

   //when moving backwards or standing and brake is pressed, switch to reverse

   if((rev<0||flatVelo.sqrMagnitude<0.5)&&brake>0.1)

      gear=0;

   if(gear==0)

   {   

      //when in reverse, flip brake and gas

      tmp=brake;

      brake=motor;

      motor=tmp;

      

      //when moving forward or standing and gas is pressed, switch to drive

      if((rev>0||flatVelo.sqrMagnitude<0.5)&&brake>0.1)

         gear=1;

   }

   engineForce=flatDir*CalcEngine();

   totalbrake=brake+handbrake*0.5;

   if(totalbrake>1.0)totalbrake=1.0;

   brakeForce=-flatVelo.normalized*totalbrake*rigidbody.mass*maxBrakeAccel;
   flatDir*=flatVelo.magnitude;

   flatDir=Quaternion.AngleAxis(steer*30.0,Vector3.up)*flatDir;

   flatDir*=rev;

   diff=(flatVelo-flatDir).magnitude;

   cornerAccel=maxCornerAccel;

   if(cornerAccel>diff)cornerAccel=diff;

   cornerForce=-(flatVelo-flatDir).normalized*cornerAccel*rigidbody.mass;

   cornerSlip=Mathf.Pow(cornerAccel/maxCornerAccel,3);

   

   rigidbody.AddForceAtPosition(brakeForce+engineForce+cornerForce,transform.position+transform.up*wheelY);

   

   handbrakeFactor=1+handbrake*4;

   if(rev<0)

      handbrakeFactor=1;

   veloSteer=((15/(2*velo.magnitude+1))+1)*handbrakeFactor;

   steerGrip=(1-handlingTendency*cornerSlip);

   if(rev*steer*steerVelo<0)

      steerGrip=1;

   maxRotSteer=2*Time.fixedDeltaTime*handbrakeFactor*steerGrip;

   fVelo=velo.magnitude;

   veloFactor=fVelo<1.0?fVelo:Mathf.Pow(velo.magnitude,0.3);

   steerVeloInput=rev*steer*veloFactor*0.5*Time.fixedDeltaTime*handbrakeFactor;

   if(velo.magnitude<0.1)

      steerVeloInput=0;

   if(steerVeloInput>steerVelo)

   {

      steerVelo+=0.02*Time.fixedDeltaTime*veloSteer;

      if(steerVeloInput<steerVelo)

         steerVelo=steerVeloInput;

   }

   else

   {

      steerVelo-=0.02*Time.fixedDeltaTime*veloSteer;

      if(steerVeloInput>steerVelo)

         steerVelo=steerVeloInput;

   }

   steerVelo=Mathf.Clamp(steerVelo,-maxRotSteer,maxRotSteer);   

   transform.Rotate(Vector3.up*steerVelo*57.295788);

}
function FixedUpdate () {

   //query input axes if necessarry

   if(queryUserInput)

   {

      brake = Mathf.Clamp01(-Input.GetAxis("Vertical"));

      handbrake = Input.GetButton("Jump")?1.0:0.0;

      steer = Input.GetAxis("Horizontal");

       motor = Mathf.Clamp01(Input.GetAxis("Vertical"));

    }

   else

   {

      motor = 0;

      steer = 0;

      brake = 0;

      handbrake = 0;

   }


   //if car is on ground calculate handling, otherwise just rev the engine

    if(onGround)

      HandlePhysics();

   else

      CalcEngine();   

      

   //wheel GFX

   UpdateWheels();
   //engine sounds

   audio.pitch=0.5+0.2*motor+0.8*engineRPM/maxRPM;

   audio.volume=0.5+0.8*motor+0.2*engineRPM/maxRPM;

}
//Called by DamageReceiver if boat destroyed

function Detonate()

{

   //destroy wheels

   for( w in wheels )

      w.coll.gameObject.active=false;
   //no more car physics

   enabled=false;

}
@script RequireComponent (Rigidbody)

@script RequireComponent (AudioSource)

markq

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