Could somone modify a bit od code for me please,

Unity Engine
,
1

Hi all

Ive got a bit of code used to control a car (taken from this tutorial), I would like it modified to be able to use the accelerometer (turn the car), auto accelerate and touch the screen to brake. I would imagine it wouldn’t be hard for someone who knows how, but im a GFX man so I have no idea. I know its not the best car script ever, but its more for testing than release.

I would be very grateful if anyone could help me out.

Thanks in advance!

// ----------- CAR TUTORIAL SAMPLE PROJECT, ? Andrew Gotow 2009 -----------------

// These variables allow the script to power the wheels of the car.
var FrontLeftWheel : WheelCollider;
var FrontRightWheel : WheelCollider;

// These variables are for the gears, the array is the list of ratios. The script
// uses the defined gear ratios to determine how much torque to apply to the wheels.
var GearRatio : float[];
var CurrentGear : int = 0;

// These variables are just for applying torque to the wheels and shifting gears.
// using the defined Max and Min Engine RPM, the script can determine what gear the
// car needs to be in.
var EngineTorque : float = 600.0;
var MaxEngineRPM : float = 3000.0;
var MinEngineRPM : float = 1000.0;
private var EngineRPM : float = 0.0;



function Start () {
	// I usually alter the center of mass to make the car more stable. I'ts less likely to flip this way.
	rigidbody.centerOfMass.y = -1.25;
}

function Update () {
	
	// This is to limith the maximum speed of the car, adjusting the drag probably isn't the best way of doing it,
	// but it's easy, and it doesn't interfere with the physics processing.
	rigidbody.drag = rigidbody.velocity.magnitude / 200;
	
	// Compute the engine RPM based on the average RPM of the two wheels, then call the shift gear function
	EngineRPM = (FrontLeftWheel.rpm + FrontRightWheel.rpm)/2 * GearRatio[CurrentGear];
	ShiftGears();

	// set the audio pitch to the percentage of RPM to the maximum RPM plus one, this makes the sound play
	// up to twice it's pitch, where it will suddenly drop when it switches gears.
	audio.pitch = Mathf.Abs(EngineRPM / MaxEngineRPM) + 1 ;
	// this line is just to ensure that the pitch does not reach a value higher than is desired.
	if ( audio.pitch > 3.0 ) {
		audio.pitch = 3.0;
	}

	// finally, apply the values to the wheels.	The torque applied is divided by the current gear, and
	// multiplied by the user input variable.
	FrontLeftWheel.motorTorque = EngineTorque / GearRatio[CurrentGear] * Input.GetAxis("Vertical");
	FrontRightWheel.motorTorque = EngineTorque / GearRatio[CurrentGear] * Input.GetAxis("Vertical");
		
	// the steer angle is an arbitrary value multiplied by the user input.
	FrontLeftWheel.steerAngle = 10 * Input.GetAxis("Horizontal");
	FrontRightWheel.steerAngle = 10 * Input.GetAxis("Horizontal");
}

function ShiftGears() {
	// this funciton shifts the gears of the vehcile, it loops through all the gears, checking which will make
	// the engine RPM fall within the desired range. The gear is then set to this "appropriate" value.
	if ( EngineRPM >= MaxEngineRPM ) {
		var AppropriateGear : int = CurrentGear;
		
		for ( var i = 0; i < GearRatio.length; i ++ ) {
			if ( FrontLeftWheel.rpm * GearRatio[i] < MaxEngineRPM ) {
				AppropriateGear = i;
				break;
			}
		}
		
		CurrentGear = AppropriateGear;
	}
	
	if ( EngineRPM <= MinEngineRPM ) {
		AppropriateGear = CurrentGear;
		
		for ( var j = GearRatio.length-1; j >= 0; j -- ) {
			if ( FrontLeftWheel.rpm * GearRatio[j] > MinEngineRPM ) {
				AppropriateGear = j;
				break;
			}
		}
		
		CurrentGear = AppropriateGear;
	}
}
2

Anyone?

3

I experimented with the very same script recently. To auto accelerate you can change the following in the update loop:

FrontLeftWheel.motorTorque = EngineTorque / GearRatio[CurrentGear];
FrontRightWheel.motorTorque = EngineTorque / GearRatio[CurrentGear];

And for steering you could use the following:

FrontLeftWheel.steerAngle = 20 * -Input.acceleration.y;
FrontRightWheel.steerAngle = 20 * -Input.acceleration.y;

4

Might have to take a look at that script.

5

Thanks, Mr Wong.

Were you working with that script on the iphone?

6

Yes I was, with iphone 3g. By the way, for some reason I had problems with performance when there were AI cars in the scene until I changed the waypoints array in the AI Car script into a builtin array. Just in case you run into the same problem.

I think basicly I added these two lines to the ai car script:

var builtinArray : Transform []; // this should be at the top, before Start()

builtinArray = waypoints.ToBuiltin(Transform); // last line of getwaypoints()

And then in the function NavigateTowardsWaypoint(), I replaced the waypoints array so that the first line looked like this:

 		RelativeWaypointPosition = transform.InverseTransformPoint( Vector3( 
												builtinArray[currentWaypoint].position.x, 
												transform.position.y, 
												builtinArray[currentWaypoint].position.z ) );
7

Thanks, ill give that a try in a few days, happy new year!

Edit

Excellent!