根据距离加速

using UnityEngine;

using System.Collections;



public class addSpeed : MonoBehaviour {



    public float scrollSpeed;



    float defaultScroll = 0.01f;

    float maxScrollSpeed = 0.7f;

    public float maxScrollSpeedDist = 100;

    public float distance = 0;



    // Use this for initialization

    void Start () {

        scrollSpeed = defaultScroll;

    }

    

    // Update is called once per frame

    void Update () {



        if(distance < maxScrollSpeedDist){

            //根据距离计算增速

            if(maxScrollSpeed > scrollSpeed)

                scrollSpeed = defaultScroll + (((maxScrollSpeedDist - (maxScrollSpeedDist - distance)) / maxScrollSpeedDist) * (maxScrollSpeed - defaultScroll));

            //根据速度做移动

            transform.position -= Vector3.right * scrollSpeed * Time.deltaTime * 200;

            //计算距离

            distance += scrollSpeed * Time.deltaTime * 250;

        }

    }

}