Unity Lerp

In Unity, the Lerp function is commonly used to smoothly interpolate between two values over time. It is a very useful function for creating animations, transitions, and other dynamic effects in your game.

Syntax

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

• a : The starting value.
• b : The ending value.
• t : The interpolation parameter.

Description

The Lerp function takes three arguments: the starting value (a), the ending value (b), and the interpolation parameter (t).

The interpolation parameter is typically a value between 0 and 1 that represents the progress or completion of an animation or transition. A value of 0 means the animation is at the beginning, and a value of 1 means the animation is complete.

The Lerp function then returns a value that is linearly interpolated between the starting and ending values based on the interpolation parameter. The value returned will be a value between a and b, and will be proportional to the value of t. For example, if t=0.5, the returned value will be exactly halfway between a and b.

Examples

Example 1: Simple interpolation

using UnityEngine;

public class Example : MonoBehaviour
{
    public float startValue = 1.0f;
    public float endValue = 5.0f;
    public float duration = 2.0f;

    private float elapsedTime = 0.0f;
    
    void Update()
    {
        elapsedTime += Time.deltaTime;
        
        float t = elapsedTime / duration;
        
        float currentValue = Mathf.Lerp(startValue, endValue, t);
        
        transform.position = new Vector3(currentValue, 0, 0);
    }
}

In this example, we have a simple animation where an object moves from startValue to endValue over a period of duration seconds. We calculate the currentValue each frame using Mathf.Lerp, and use that value to set the object's position.

Example 2: Color interpolation

using UnityEngine;

public class Example : MonoBehaviour
{
    public Color startColor = Color.red;
    public Color endColor = Color.blue;
    public float duration = 2.0f;

    private float elapsedTime = 0.0f;
    
    void Update()
    {
        elapsedTime += Time.deltaTime;
        
        float t = elapsedTime / duration;
        
        Color currentColor = Color.Lerp(startColor, endColor, t);
        
        GetComponent<Renderer>().material.color = currentColor;
    }
}

In this example, we have an object that changes color from startColor to endColor over a period of duration seconds. We calculate the currentColor each frame using Color.Lerp, and use that value to set the object's material color.

Conclusion

The Lerp function is an essential tool for creating smooth transitions and animations in Unity. By understanding how to use this function, you can greatly enhance the visual appeal and user experience of your game.