Vector3.Lerp

Parameters

Description

Linearly interpolates between two vectors.

Interpolates between the vectors a and b by the interpolant t. The parameter t is clamped to the range [0, 1]. This is most commonly used to find a point some fraction of the way along a line between two endpoints (e.g. to move an object gradually between those points).

When t = 0 returns a. When t = 1 returns b. When t = 0.5 returns the point midway between a and b.

	// Transforms to act as start and end markers for the journey.
	var startMarker: Transform;
	var endMarker: Transform;
	
	// Movement speed in units/sec.
	var speed = 1.0;
	
	// Time when the movement started.
	private var startTime: float;
	
	// Total distance between the markers.
	private var journeyLength: float;	
	
	function Start() {
		// Keep a note of the time the movement started.
		startTime = Time.time;
		
		// Calculate the journey length.
		journeyLength = Vector3.Distance(startMarker.position, endMarker.position);
	}
	
	// Follows the target position like with a spring
	function Update () {
		// Distance moved = time * speed.
		var distCovered = (Time.time - startTime) * speed;
		
		// Fraction of journey completed = current distance divided by total distance.
		var fracJourney = distCovered / journeyLength;
		
		// Set our position as a fraction of the distance between the markers.
		transform.position = Vector3.Lerp(startMarker.position, endMarker.position, fracJourney);
	}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Transform startMarker;
    public Transform endMarker;
    public float speed = 1.0F;
    private float startTime;
    private float journeyLength;
    void Start() {
        startTime = Time.time;
        journeyLength = Vector3.Distance(startMarker.position, endMarker.position);
    }
    void Update() {
        float distCovered = (Time.time - startTime) * speed;
        float fracJourney = distCovered / journeyLength;
        transform.position = Vector3.Lerp(startMarker.position, endMarker.position, fracJourney);
    }
}

See Also: Slerp, LerpUnclamped.