Accelerating and Decelerating a Characters's speed

Questions & Answers
1

I’m looking to have a character accelerated when moving forward, decelerate when movement keys aren’t pressed (keyboard/joystick), and slide when on certain surfaces.

I have managed to accelerate the player, but I’m having issues with the deceleration.
I assume is because I’m multiplying the moveDirection Vector’s forward and right (z and x) by Input.GetAxis (which becomes 0 when they are let go.)

After that I’ll know how to code in the friction.

I’ve attached the segments of my player script that deals with movement exclusively. This is for a 3D platformer by the way, similar to Mario 64/Galaxy.

Any help would be wonderful. Thanks in advance!

 //=====================================================================
// CalculateMovement
//=====================================================================
function CalculateMovement()
{
	var jumpButton = Input.GetButton("Jump");
	var jumpButtonPressed = Input.GetButtonDown("Jump"); 
	var dodge = Input.GetKeyDown(KeyCode.DownArrow);
	
    x  = Input.GetAxis("Horizontal");
    z  = Input.GetAxis("Vertical"); 
	y  = moveDirection.y;	
	
	if (x != 0 || z != 0)
	isMoving = true;
	
	else if (x == 0 && z == 0)
	isMoving = false;
	
    horizontalSpeed = horizontalVelocity.magnitude;
    verticalSpeed = controller.velocity.y;
    overallSpeed = controller.velocity.magnitude;

	var cameraTransform : Transform  = Camera.main.transform;

	var forward : Vector3 = cameraTransform.TransformDirection(Vector3.forward);
	forward.y = 0;
	forward = forward.normalized;
	
	var right = Vector3(forward.z, 0, -forward.x);
	
	if ((!isAttacking) && canMove && isMoving)
	{	
		moveDirection = x * right + z * forward;
	}

	if (moveDirection != Vector3.zero)
	{
		curSpeed += speed * Time.deltaTime;
		curSpeed = Mathf.Clamp(curSpeed,0,maxSpeed);	
	}

	if (!isMoving && canMove)
	{
		curSpeed -= (friction) * Time.deltaTime;
		
		if (curSpeed < 0)
			curSpeed = 0;	
	}
}

//=====================================================================
// ApplyMovement
//=====================================================================
function ApplyMovement()
{
		 
	// Move the controller
	if (!busy))
	{
		var recalcMoveDir : Vector3 = Vector3(moveDirection.x,0,moveDirection.z)*curSpeed;
		recalcMoveDir.y = moveDirection.y;
		
		controller.Move((recalcMoveDir) * Time.deltaTime); 
	}
}
2

Well, the CharacterController has been invented so it’s not affected by momentum or other external forces. If you want it to behave like a physic object you might want to use a Rigidbody instead. A Rigidbody can be moved via AddForce and it’s automatically affected by friction and gravity. The friction can be modified by the PhysicMaterial of the surface.