How to set vCam orthographic size relative to velocity?

Question

I'm trying to make it so that when my player velocity increases, the virtual follow cam orthographic size increases and when the player velocity decreases, the orthographic size decreases. When I try this though, it doesn't scale smoothly, it judders really badly.

My code looks something like this...

void Update()
{
    // Take the fastest velocity (x or y)
    if((Mathf.Abs(rb.velocity.x) > Mathf.Abs(rb.velocity.y))
    {
        velocity = Mathf.Abs(rb.velocity.x)
    }
    else
    {
        velocity = Mathf.Abs(rb.velocity.y)
    }
 
    //Set orthogrpahic camera size
    if(velocity > 0)
    {
        vCam.m_Lens.OrthographicSize = Mathf.Clamp(defaultCamSize + velocity, defaultCamSize, maxCamSize);
    }
    else
    {
        vCam.m_Lens.OrthographicSize = defaultCamSize;
    }
}

Answer 1

You could use Mathf.Lerp(), documentation says that

Returns float The interpolated float result between the two float values.

Description
Linearly interpolates between a and b by t.
The parameter t is clamped to the range [0, 1].
When t = 0 returns a. When t = 1 return b. When t = 0.5 returns the midpoint of a and b.

You can write somthing like following to smoothly change the orthographicSize

private void Update() 
{
    velocity = Mathf.Max(Mathf.Abs(rb.velocity.x), Mathf.Abs(rb.velocity.y));
    float lerpSpeed = .05f;
    float newSize = Mathf.Clamp(defaultCamSize + velocity, defaultCamSize, maxCamSize);
    vCam.m_Lens.OrthographicSize = Mathf.Lerp(vCam.m_Lens.OrthographicSize, 
                                   velocity > 0 ? newSize : defaultCamSize,
                                   lerpSpeed);
}

Answer 2

// Take the fastest velocity (x or y)

If you did this, the velocity swung widely when the player moved sidelong, you'd better use velocity = rb.velocity.magnitude / 2f instead.