Help Implementing Manual Transmission Into My Current Code

Unity Engine
1

Hello,

Ive been trying for a little bit to implement manual transmission with gear ratios and a clutch into my current code.It is for a big rig and has 2 scripts.1 connects to the car,and the other connects to each wheel.The scripts are below.If you have any advice to implement manual transmission into the script please help if you like.There are not a lot of scripts around about manual transmission and the ones I’ve found i cant get to implement into my script properly.

Car Script

var wheelFL : Transform;
var wheelFR : Transform;
var wheelML : Transform;
var wheelMR : Transform;
var wheelBL : Transform;
var wheelBR : Transform;

var frontWheelSteering = false;
var middleWheelSteering = false;
var rearWheelSteering = false;

var frontWheelDrive = false;
var middleWheelDrive = false;
var rearWheelDrive = false;

var minSteeringAngle = 0.00;
var maxSteeringAngle = 0.00;
var highSpeed = 0.00;

var motorMass = 1.00;
var motorDrag = 0.00;
var maxAcceleration = 0.00;
var maxMotorSpeed = 0.00;
var minTorque = 0.00;
var maxTorque = 0.00;

var centerOfMass : Vector3;
rigidbody.centerOfMass = centerOfMass;

private var scriptWheelFL : Wheel;
private var scriptWheelFR : Wheel;
private var scriptWheelML : Wheel;
private var scriptWheelMR : Wheel;
private var scriptWheelBL : Wheel;
private var scriptWheelBR : Wheel;
scriptWheelFL = wheelFL.GetComponent(Wheel);
scriptWheelFR = wheelFR.GetComponent(Wheel);
scriptWheelML = wheelML.GetComponent(Wheel);
scriptWheelMR = wheelMR.GetComponent(Wheel);
scriptWheelBL = wheelBL.GetComponent(Wheel);
scriptWheelBR = wheelBR.GetComponent(Wheel);
scriptWheelFL.car = this;
scriptWheelFR.car = this;
scriptWheelML.car = this;
scriptWheelMR.car = this;
scriptWheelBL.car = this;
scriptWheelBR.car = this;

var steeringInput = 0.00;
var motorInput = 0.00;

var motorTorque = 0.00;
var motorAccel = 0.00;
var motorSpeed = 0.00;
var steeringAngle = 0.00;

if(frontWheelDrive) scriptWheelFL.driven = scriptWheelFR.driven = true;
if(middleWheelDrive) scriptWheelML.driven = scriptWheelMR.driven =  true;
if(rearWheelDrive) scriptWheelBL.driven = scriptWheelBR.driven =  true;

function FixedUpdate ()
{
	steeringInput = Input.GetAxis("Horizontal");
	motorInput = Input.GetAxis("Vertical");
	
	if(frontWheelSteering) wheelFL.localRotation = wheelFR.localRotation = Quaternion.LookRotation(Vector3(steeringInput * (steeringAngle / 90), 0, 1 + (-1 * Mathf.Abs(steeringInput * (steeringAngle / 90))) ));
	if(middleWheelSteering) wheelML.localRotation = wheelMR.localRotation = Quaternion.LookRotation(Vector3(-steeringInput * (steeringAngle / 90), 0, 1 + (-1 * Mathf.Abs(steeringInput * (steeringAngle / 90))) ));
	if(rearWheelSteering) wheelBL.localRotation = wheelBR.localRotation = Quaternion.LookRotation(Vector3(-steeringInput * (steeringAngle / 90), 0, 1 + (-1 * Mathf.Abs(steeringInput * (steeringAngle / 90))) ));
	
	if(frontWheelDrive || middleWheelDrive || rearWheelDrive)
	{
		motorTorque = Mathf.Lerp(maxTorque / 30, minTorque / 30, motorSpeed / maxMotorSpeed) * Mathf.Abs(motorInput);
		if(motorTorque < 1) motorTorque = 1;
		motorAccel = Mathf.Lerp(maxAcceleration, 0, motorSpeed / maxMotorSpeed);
		steeringAngle = Mathf.Lerp(maxSteeringAngle, minSteeringAngle, rigidbody.velocity.magnitude / highSpeed);

		motorSpeed += motorInput * motorAccel / motorMass * Time.fixedDeltaTime;
		
		if(frontWheelDrive)
		{
			scriptWheelFL.speed = scriptWheelFR.speed = motorSpeed;
		}
		
		if(middleWheelDrive)
		{
			scriptWheelML.speed = scriptWheelMR.speed = motorSpeed;
		}
		
		if(rearWheelDrive)
		{
			scriptWheelBL.speed = scriptWheelBR.speed = motorSpeed;
		}
		
		motorSpeed += -motorSpeed * motorDrag / motorTorque * Time.fixedDeltaTime;
	}
} 

function AddForceOnMotor (force : float)
{
	motorSpeed += force / motorTorque;
}

Wheel Script

var mass = 1.00;
var wheelRadius = 0.00;
var suspensionRange = 0.00;
var suspensionForce = 0.00;
var suspensionDamp = 0.00;
var compressionFrictionFactor = 0.00;

var sidewaysFriction = 0.00;
var sidewaysDamp = 0.00;
var sidewaysSlipVelocity = 0.00;
var sidewaysSlipForce = 0.00;
var sidewaysSlipFriction = 0.00; 
var sidewaysStiffnessFactor = 0.00;

var forwardFriction = 0.00;
var forwardSlipVelocity = 0.00;
var forwardSlipForce = 0.00;
var forwardSlipFriction = 0.00;
var forwardStiffnessFactor = 0.00; 

var frictionSmoothing = 1.00;

private var hit : RaycastHit;

private var parent : Rigidbody;
parent = transform.root.rigidbody;

private var graphic : Transform;
graphic = transform.FindChild("Graphic");

private var wheelCircumference = 0.00;
wheelCircumference = wheelRadius * Mathf.PI * 2;

private var usedSideFriction = 0.00;
private var usedForwardFriction = 0.00;
private var sideSlip = 0.00;
private var forwardSlip = 0.00;

var car : Car;
var driven = false;

var speed = 0.00;

var brake = false;
var skidbrake = false;

function FixedUpdate ()
{
	down = transform.TransformDirection(Vector3.down); 
	if(Physics.Raycast (transform.position, down, hit, suspensionRange + wheelRadius)  hit.collider.transform.root != transform.root)
	{
		velocityAtTouch = parent.GetPointVelocity(hit.point);
		
		compression = hit.distance / (suspensionRange + wheelRadius);
		compression = -compression + 1;
		force = -down * compression * suspensionForce;
		
		t = transform.InverseTransformDirection(velocityAtTouch);
		t.z = t.x = 0;
		shockDrag = transform.TransformDirection(t) * -suspensionDamp;
		
		forwardDifference = transform.InverseTransformDirection(velocityAtTouch).z - speed;
		newForwardFriction = Mathf.Lerp(forwardFriction, forwardSlipFriction, forwardSlip * forwardSlip);
		newForwardFriction = Mathf.Lerp(newForwardFriction, newForwardFriction * compression * 1, compressionFrictionFactor);
		if(frictionSmoothing > 0)
			usedForwardFriction = Mathf.Lerp(usedForwardFriction, newForwardFriction, Time.fixedDeltaTime / frictionSmoothing);
		else
			usedForwardFriction = newForwardFriction;
		forwardForce = transform.TransformDirection(Vector3(0, 0, -forwardDifference)) * usedForwardFriction;
		forwardSlip = Mathf.Lerp(forwardForce.magnitude / forwardSlipForce, forwardDifference / forwardSlipVelocity, forwardStiffnessFactor);
		
		sidewaysDifference = transform.InverseTransformDirection(velocityAtTouch).x;
		newSideFriction = Mathf.Lerp(sidewaysFriction, sidewaysSlipFriction, sideSlip * sideSlip);
		newSideFriction = Mathf.Lerp(newSideFriction, newSideFriction * compression * 1, compressionFrictionFactor);
		if(frictionSmoothing > 0)
			usedSideFriction = Mathf.Lerp(usedSideFriction, newSideFriction, Time.fixedDeltaTime / frictionSmoothing);
		else
			usedSideFriction = newSideFriction;
		sideForce = transform.TransformDirection(Vector3(-sidewaysDifference, 0, 0)) * usedSideFriction;
		sideSlip = Mathf.Lerp(sideForce.magnitude / sidewaysSlipForce, sidewaysDifference / sidewaysSlipVelocity, sidewaysStiffnessFactor);
		
		t = transform.InverseTransformDirection(velocityAtTouch);
		t.z = t.y = 0;
		sideDrag = transform.TransformDirection(t) * -sidewaysDamp;
		
		parent.AddForceAtPosition(force + shockDrag + forwardForce + sideForce + sideDrag, hit.point);

		if(driven)
			car.AddForceOnMotor (forwardDifference * usedForwardFriction * Time.fixedDeltaTime);
		else
			speed += forwardDifference;	

		graphic.position = transform.position + (down * (hit.distance - wheelRadius));
	}
	else
	{
		graphic.position = transform.position + (down * suspensionRange);
	}
	
	graphic.transform.Rotate(360 * (speed / wheelCircumference) * Time.fixedDeltaTime, 0, 0); 
}
2

Kinda disappointing there isn’t even one reply.Im not asking for you to do the recoding but just for some help,and some wise words of advice,even some help pointing me in the right direction.Thats all.

3

I’m not sure if it’s clear what you’re looking for. Do the scripts you posted not work the way you want them to? Is there a specific problem that you’re looking for a solution to?

4

No there isnt.I need help putting manual transmission with gears into the script.The script right now will move the truck forward and reverse but there are no gears to regulate power,and speed.

I tried implementing gears my self but i took the cowboy approach by not knowing a single thing about gears or transmission in unity and it is a very small topic on the unity forum.I have looked at other car scripts with manual but it didnt help me.

5

I think for most people providing any sort of useful feedback would involve some pretty heavy digging into the code you posted. Maybe someone will tackle it, but it would involve quite a bit of work for most people, I think.

But who knows, maybe someone will be up for it. I’d recommend though that at the very least you repost your code with better formatting. Replace all tabs with spaces, and break any lines that wrap (or are likely to) in a reasonable way. As it is now, the code is quite difficult to read (for me at least) due to the formatting problems.

6

Ok well thanks for the advice.Hopefully someone will tackle it like you said!