Speeding Up and Slowing Down

Unity Engine
1

Hello all I am trying to write a basic movement script and so far I am having problems with the forward and backward movement.

Basically when the player presses the Up arrow, I want the ship to accelerate forward, slowly at first then speeding up depending on how long the person holds the key.

I was trying to do this by AddRelativeForce, but it seemed to become uncontrollable sometimes.

I also want to start slowing the player down when they release the button, bringing them to a gradual stop.

I know that I probably should use Time.deltaTime, but I was wondering if anyone could give me any tips in the right direction? Here is my current code:

var shipspeed = -300;  
			var rotationspeed = 200;
			var translation;
			if( Input.GetKey( "up" ) ) // move left
			{
				translation = Input.GetAxis ("Vertical") * shipspeed; 
				translation *= Time.deltaTime; 
				
				transform.Translate (0, 0, translation); 
			}
			
			if( Input.GetKey( "left" ) ) // move left
			{
				transform.Rotate(0,Input.GetAxis("Horizontal") * rotationspeed * Time.deltaTime, 0);
			}
			
			if( Input.GetKey( "right" ) ) // move left
			{
				transform.Rotate(0,Input.GetAxis("Horizontal") * rotationspeed * Time.deltaTime, 0);
			}
			
			if( Input.GetKey( "down" ) ) // move left
			{
				translation = Input.GetAxis ("Vertical") * shipspeed/2; 
				translation *= Time.deltaTime; 
				
				transform.Translate (0, 0, translation); 
			}

I think that I should also use rigidbody velocity, but it seems to move only one way and very slowly when I try that.

Does anyone have any examples that might help me?

Thank you for anything :slight_smile:

2

Based on your description, it sounds like a rigid body and applied forces is what you want. I imagine that getting the right behavior (speeding up and slowing down appropriately and not becoming ‘uncontrollable’) will just be a matter of setting the various parameters (mass, thrust, drag, etc.) appropriately.