How can I make a camera zoom script in c# for unity?

Question

I want a c# script so when I hold right click it zooms in a little and when you stop holding right click it goes back to its original position.

Answer 1

You would first want to store the original camera z distance. (As I assume you want it to go forward in the z direction). Then you would want to have a float for the amount of tome zoom was held down. (Increase it when zooming, and decrease it when you dont click it). Also have a target z, so it doesn't go too far

public float startZ;
public float targetZ;
public float zoomInSpeed;
public float zoomOutSpeed;

float heldDownTime;
float originalZ;
void Start()
{
    startZ = transform.position.z;
}
void Update()
{
    if (Input.GetKey(KeyCode.Mouse0))
    {
         heldDownTime += Time.deltaTime * zoomInSpeed;
    }
    else
    {
         heldDownTime -= Time.deltaTime * zoomOutSpeed;
         heldDownTime = Mathf.Clamp(heldDownTime, 0, Mathf.Infinity);
    }
    float smoothed = System.Math.Tanh(heldDownTime);
    Vector3 pos = transform.position;
    transform.position = new Vector3(pos.x, pos.y, startZ + smoothed * (targetZ - startZ));
}

I basically get the time held down, then I smooth it out, so it doesn't zoom to far forward.

Let me know in the comments if you get any errors!