How to make car accelerate/decelerate over time

Question

So I'm attempting to make a realistic feeling car. I've got it running, turns feel alright, just how do I make it break appropriately, speed up appropriately, etc etc. I tried, not much luck, but it does stop for a second, go to 8 speed, then go to 30.

 //inspector variables
 
 var speed:float; //speed of the car, tweek as needed based on your scale
 var turnSpeed:float; //turn speed
 var timecar:float;
 var accel: float;
 function Update()
 {
    timecar += Time.deltaTime;
     //grab the input axes
     var steer=Input.GetAxis("Horizontal");
     var gas=Input.GetAxis("Vertical");
 
     //if they're hittin' the gas...
     if (gas!=0)
     {
      InvokeRepeating("addspeed", 1.0, 1.0);
            //take the throttle level (with keyboard, generally +1 if up, -1 if down)
         //  and multiply by speed and the timestep to get the distance moved this frame
         var moveDist=gas*speed*Time.deltaTime;
 
         //now the turn amount, similar drill, just turnSpeed instead of speed
         //   we multiply in gas as well, which properly reverses the steering when going 
         //   backwards, and scales the turn amount with the speed
         var turnAngle=steer * turnSpeed * Time.deltaTime * gas;
 
         //now apply 'em, starting with the turn
         transform.rotation.eulerAngles.y+=turnAngle;
 
         //and now move forward by moveVect
         transform.Translate(Vector3.forward*moveDist);
     }
  }
  function addspeed (){
  if (speed < 30){
  speed++;
  }
  }

I've never tried making a racing game in Unity, so I'm completely new to this. I do however have a good amount of experience I Unity as a whole. Thanks for helping!

Just a side-note, the Car Demo provided by Unity won't work, and I didn't want to use it anyways, I prefer making games from scratch.

Answer 1

Best Answer

Answer by clunk47 · Dec 16, 2012 at 02:58 AM

Try making an acceleration var float. Like:

var accel : float = 1.0f;

then if(gas) speed+= Input.GetAxis("Vertical") * accel;

Of course this isn't formatted "code", it's Just an example of something you could try...

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3 · Dec 16, 2012 at 03:53 AM 1

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Sorry, do you mean like: var accel: float; if (gas = true) { speed+=Input.GetAxis("Vertical")*accel; }

Doesnt seem to work...

clunk47 · Dec 16, 2012 at 03:58 AM 0

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This isn't a copy and paste script, it is an example you could use to implement into your script. I would write out a script for you but I am about to get some sleep. If you don't figure it out by tomorrow I will work with you more on this :)

3 · Dec 16, 2012 at 04:18 AM 2

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alright, Yours looks the best honestly, so I'll try to alter yours. If a variation of yours works, Ill give you a check!

Thanks,

CapitalKage · Feb 12 at 08:36 AM 0

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Just in case anyone else reference's this post in the future. I took the advice from @clunk47 and it would look something like this. Of course, you can add a Time adjustment in or even use velocity but, this is a quick way to get the "acceleration/deceleration" going.

float speed; float acceleration = 1f;

if (Input.GetKey(KeyCode.W) && speed <= 30) { transform.Translate(Vector3.forward Time.deltaTime (speed += accel) verticalInput); } else if (Input.GetKey(KeyCode.W) && speed >= 30) { speed = 30; transform.Translate(Vector3.forward Time.deltaTime speed verticalInput); } else { speed = 0; }

Answer 2

Answer by aburningflame · Dec 16, 2012 at 03:46 AM

Not sure what youre trying to accomplish but if if (Input.GetKeyDown("s")) { speed = 1; while (speed < 16){ speed++; timecar = 0; }

is in an Update function..then if s is pressed speed will always be 16. (Because in 1 tick of update you are looping WHILE speed<16...so that loop will execute 15+ times in 1 update tick - forcing your speed to 16 right away.

You should just do: private int maxSpeed=16; if (Input.GetKeyDown(KeyCode.S)){ speed++; if (speed>maxSpeed) speed=maxSpeed; }else{ speed--; //decelerate speed maybe? }

This allows acceleration over time I suppose.

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3 · Dec 16, 2012 at 03:50 AM 0

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Also doesn't work...

Its not based on time,

What am I doing wrong?

aburningflame · Dec 21, 2012 at 02:21 AM 0

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sorry im not sure i understand. Update() is called every game tick. if S is down, you want to increase your speed. You may need to speed++ every second or so. Im not too sure what youre tryin gto do so its hard to help.

How to make car accelerate/decelerate over time

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