# Math in Unity : Linear Interpolation(Part II)

What we did earlier was simply create a Move () method and set a position.
It is true that with Time.time the hope moves constantly, but using a simple float the sphere “finds” its position between Point A and Point B.

To create a linear interpolation instead, we have to make the sphere move from Point A to the desired point.

To do this, we will create a Lerp() method from scratch.

The reference for the Vector3.Lerp method is this
https://docs.unity3d.com/ScriptReference/Vector3.Lerp.html

As we can see from the description,
t =0 represents point A,
t =1 represents point B
and t = 0.5 represents the halfway point between point A and point B.

We now know that the Lerp method requires two Vectors, A and B, and a float t.

The formula, as the documentation says, is this

# a + (b - a) * t

We can also read this formula like this
a + (length of b - a) multiplied by a float t
So far everything pretty simple right?

Let’s translate it into code

first, we need the distance from Point B to Point A

After this, let’s translate the formula

The last piece of our code is to set the t as CLAMP
The reference for the MathF.Clamp
https://docs.unity3d.com/ScriptReference/Mathf.Clamp.html

The clamp method requires three parameters: one float for a value and two floats for a minimum and a maximum value.

The first value is none other than value of t, and the Clamp will be between 0 and 1.

And return the new Vector3

If we now set the Lerp() in Start()

If we test it

The sphere moves from point A but stops when it reaches point B.

In the next articles we start talking about Planes.

## More from Matteo Lo Piccolo

Always in love with programming, even if late (I'm already 39 years old) I decided to follow my dream! We will see how far my passion will take me!

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## Matteo Lo Piccolo

Always in love with programming, even if late (I'm already 39 years old) I decided to follow my dream! We will see how far my passion will take me!