How to start Vector3.Lerp from middle point?

Question

I have to move object from -10 to +10 x position. But I want to start my object from zero x.point to move, how can I start my lerp at the middle position?

Edit2: Object should start at x = 0 position and move to +10 x position and go to -10 x position and again +10 x, -10 x like a loop.

Vector3 pos1, pos2, pos0, pos3;
void Start()
{
    pos0 = transform.position;

    pos1 = pos0 + new Vector3(10, 0, 0);

    pos2 = pos0 - new Vector3(10, 0, 0);

    pos3 = pos1;
}
float time = 0.5f;
void FixedUpdate()
{ 
    time += Mathf.PingPong(Time.time * 0.5f, 1.0f);
    transform.position = Vector3.Lerp(pos2, pos1, time);
}

Answer 1

Here is how I would approach it:

Vector3 ToPos;
Vector3 FromPos;

void Start()
{
    ToPos = transform.position + new Vector3(10, 0, 0);
    FromPos = transform.position - new Vector3(10, 0, 0);
}

// using Update since you are setting the transform.position directly
// Which makes me think you aren't worried about physics to much.
// Also FixedUpdate can run multiple times per frame.
void Update()
{
    // Using distance so it doesnt matter if it's x only, y only z only or a combination
    float range = Vector3.Distance(FromPos, ToPos);
    float distanceTraveled = Vector3.Distance(FromPos, transform.position);
    // Doing it this way so you character can start at anypoint in the transition...
    float currentRatio = Mathf.Clamp01(distanceTraveled / range + Time.deltaTime);

    transform.position = Vector3.Lerp(FromPos, ToPos, currentRatio);
    if (Mathf.Approximately(currentRatio, 1.0f))
    {
        Vector3 tempSwitch = FromPos;
        FromPos = ToPos;
        ToPos = tempSwitch;
    }
}