// Animates the position in an arc between sunrise and sunset.

var sunrise : Transform;
var sunset : Transform;

function Update () {
    // The center of the arc
    var center = (sunrise.position + sunset.position) * 0.5;
    // move the center a bit downwards to make the arc vertical
    center -= Vector3(0,1,0);

    // Interpolate over the arc relative to center
    var riseRelCenter = sunrise.position - center;
    var setRelCenter = sunset.position - center;
    transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, Time.time);
    transform.position += center;
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Transform sunrise;
    public Transform sunset;
    void Update() {
        Vector3 center = (sunrise.position + sunset.position) * 0.5F;
        center -= new Vector3(0, 1, 0);
        Vector3 riseRelCenter = sunrise.position - center;
        Vector3 setRelCenter = sunset.position - center;
        transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, Time.time);
        transform.position += center;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public sunrise as Transform

    public sunset as Transform

    def Update():
        center as Vector3 = ((sunrise.position + sunset.position) * 0.5F)
        center -= Vector3(0, 1, 0)
        riseRelCenter as Vector3 = (sunrise.position - center)
        setRelCenter as Vector3 = (sunset.position - center)
        transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, Time.time)
        transform.position += center