Version: 2019.4
  • C#


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public static Vector3 Lerp(Vector3 a, Vector3 b, float t);


a Start value, returned when t = 0.
b End value, returned when t = 1.
t Value used to interpolate between a and b.


Vector3 Interpolated value, equals to a + (b - a) * t.


Linearly interpolates between two points.

Interpolates between the points 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).

The value returned equals a + (b - a) * t (which can also be written a * (1-t) + b*t).
When t = 0, Vector3.Lerp(a, b, t) returns a.
When t = 1, Vector3.Lerp(a, b, t) returns b.
When t = 0.5, Vector3.Lerp(a, b, t) returns the point midway between a and b.

// A short example of Vector3.Lerp usage.
// Add it to an object in your scene, and at Play time it will draw in the Scene View a small yellow line between the scene origin, and a position interpolated between two other positions (one on the up axis, one on the forward axis).

using UnityEngine;

public class ExampleClass : MonoBehaviour { public int interpolationFramesCount = 45; // Number of frames to completely interpolate between the 2 positions int elapsedFrames = 0;

void Update() { float interpolationRatio = (float)elapsedFrames / interpolationFramesCount;

Vector3 interpolatedPosition = Vector3.Lerp(Vector3.up, Vector3.forward, interpolationRatio);

elapsedFrames = (elapsedFrames + 1) % (interpolationFramesCount + 1); // reset elapsedFrames to zero after it reached (interpolationFramesCount + 1)

Debug.DrawLine(, Vector3.up,; Debug.DrawLine(, Vector3.forward,; Debug.DrawLine(, interpolatedPosition, Color.yellow); } }
// A longer example of Vector3.Lerp usage.
// Drop this script under an object in your scene, and specify 2 other objects in the "startMarker"/"endMarker" variables in the script inspector window.
// At play time, the script will move the object along a path between the position of those two markers.

using UnityEngine; using System.Collections;

public class ExampleClass : MonoBehaviour { // Transforms to act as start and end markers for the journey. public Transform startMarker; public Transform endMarker;

// Movement speed in units per second. public float speed = 1.0F;

// Time when the movement started. private float startTime;

// Total distance between the markers. private float journeyLength;

void Start() { // Keep a note of the time the movement started. startTime = Time.time;

// Calculate the journey length. journeyLength = Vector3.Distance(startMarker.position, endMarker.position); }

// Move to the target end position. void Update() { // Distance moved equals elapsed time times speed.. float distCovered = (Time.time - startTime) * speed;

// Fraction of journey completed equals current distance divided by total distance. float fractionOfJourney = distCovered / journeyLength;

// Set our position as a fraction of the distance between the markers. transform.position = Vector3.Lerp(startMarker.position, endMarker.position, fractionOfJourney); } }

See Also: Slerp, LerpUnclamped.