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，然后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：

u#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;Unity3D教程手册

//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\ngear= "+gear+"\nrpm= "+engineRPM.ToString("f0");

}

//return an information string for the vehicle

function GetControlString(gui : GUIText) {

gui.text="Use arrow keys to control the jeep,\nspace for handbrake.";<code>Unity3D教程手册

}

//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;i1)

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(engineRPM1)

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.sqrMagnitude0.1)

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.sqrMagnitude0.1)

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;

//unity3d：http://www.unitymanual.com/

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.magnitudesteerVelo)

{

steerVelo+=0.02*Time.fixedDeltaTime*veloSteer;

if(steerVeloInputsteerVelo)

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

//unity3d脚本：http://www.unitymanual.com/

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 Req