Vector3.LerpUnclamped

Parameters

Returns

Vector3 Interpolated value. This value always lies on a line that passes through points a and b.

Description

Interpolates linearly between two vectors, allowing extrapolation beyond the end points.

Unclamped linear interpolation allows for values of t less than zero or greater than one, such that the returned vector can lie outside of the points a and b.

This method is useful for finding a point some constant rate along the line through two endpoints. For example, to move an object gradually beyond and through those points.

The returned value V equals
V = A + (B − B) × t

The method interpolates between points a and b, such that:

• When t ≤ 0, this method returns a vector that points along the line through a and b but in fornt of a.
• When 0 < t0 > 1, this method returns a vector that points along the line between a and b. The distance along the line corresponds to the fraction represented by t.
• When t > 1, this this method returns a vector that points along the line through a and b but beyond b.

// This example creates three primitive cubes. Using linear interpolation, one cube moves along the line that passes through the others.
// Because the interpolation is not clamped to the start and end points, the moving cube passes the end cube after the interpolation frame limit is reached.    
// Attach this script to any GameObject in your scene. 

using UnityEngine;

public class LerpUnclampedExample : MonoBehaviour
{
    // Number of frames in which to completely interpolate between the positions
    int interpolationFramesCount = 300; 
    int elapsedFrames = 0;

    // Number of frames to reset the moving cube to the start position
    int maxFrameReset = 900;

    GameObject CubeStart;
    GameObject CubeEnd;
    GameObject CubeMove;


    void Start()
    {
        // Create the cubes
        CubeStart = GameObject.CreatePrimitive(PrimitiveType.Cube);
        CubeStart.transform.position = new Vector3(-5,0,0);

        CubeEnd = GameObject.CreatePrimitive(PrimitiveType.Cube);
        CubeEnd.transform.position = new Vector3(5,0,0);

        CubeMove = GameObject.CreatePrimitive(PrimitiveType.Cube);
        CubeMove.transform.position =  CubeStart.transform.position;
    }

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

        // Interpolate position of the moving cube, based on the ratio of elapsed frames
        CubeMove.transform.position = Vector3.LerpUnclamped(CubeStart.transform.position, CubeEnd.transform.position, interpolationRatio);
        
        // Reset elapsedFrames to zero after it reaches maxFrameReset
        elapsedFrames = (elapsedFrames + 1) % (maxFrameReset);  

    }
}

Additional resources: Lerp SlerpUnclampes