SmoothMovement.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// @kurtdekker
//
// This is to take any continuous quantity and change it from one value
// to another over time. This code is for floats. It can be adapted to work for:
//
//	Vector2, Vector3, Vector3
//	Quaternion
//	double
//	Color
//
// ... pretty much any quantity that you want to gradually change over time.
//
// All you do is set the desiredQuantity, nothing else.
//
// The currentQuantity will be moved to the desiredQuantity.
//
// You would use the currentQuantity as the smoothly-moving value.
//
// See here for a full example runnable Unity3D package:
// https://forum.unity.com/threads/beginner-need-help-with-smoothdamp.988959/#post-6430100

public class SmoothMovement : MonoBehaviour
{
	float currentQuantity;
	float desiredQuantity;

	const float MovementPerSecond = 2.0f;

	void Start ()
	{
		// TODO: set up your initial values, if any
		currentQuantity = 1;

		// match desired
		desiredQuantity = currentQuantity;
	}

	void AcceptUserInput()
	{
		if (Input.GetKeyDown( KeyCode.Alpha1))
		{
			desiredQuantity = 1;
		}
		if (Input.GetKeyDown( KeyCode.Alpha2))
		{
			desiredQuantity = 2;
		}
		if (Input.GetKeyDown( KeyCode.Alpha3))
		{
			desiredQuantity = 3;
		}
	}

// THIS IS THE MAGIC SAUCE: smoothly move currentQuantity to desiredQuantity:
	void ProcessMovement()
	{
		// Every frame without exception move the currentQuantity
		// towards the desiredQuantity, by the movement rate:
		currentQuantity = Mathf.MoveTowards(
			currentQuantity,
			desiredQuantity,
			MovementPerSecond * Time.deltaTime);
			
		// Note: use Mathf.MoveTowardsAngle() if the quantity is in degrees
	}

	public UnityEngine.UI.Text TextOutput;
	void DisplayResults()
	{
		TextOutput.text = "Press 1, 2 or 3 to select desiredQuantity.\n\n" +
			"desiredQuantity = " + desiredQuantity + "\n" +
			"currentQuantity = " + currentQuantity + "\n";
	}

	void Update ()
	{
		AcceptUserInput();

		ProcessMovement();

		DisplayResults();
	}
}

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