Дергается фон при смене направления

using UnityEngine;
using System.Collections;
 
public class MoveBackground : MonoBehaviour
{  
    public enum ProjectMode { moveX = 0, moveY = 1 };
    public ProjectMode projectMode = ProjectMode.moveX;
 
    public MeshRenderer firstBG;
    public float firstBGSpeed = 0f;
 
    public MeshRenderer secondBG;
    public float secondBGSpeed = 0.05f;
 
    public MeshRenderer thirdBG;
    public float thirdBGSpeed = 0.1f;
 
    private Vector2 savedFirst;
    private Vector2 savedSecond;
    private Vector2 savedThird;
 
    void Awake()
    {
        if (firstBG) savedFirst = firstBG.sharedMaterial.GetTextureOffset("_MainTex");
        if (secondBG) savedSecond = secondBG.sharedMaterial.GetTextureOffset("_MainTex");
        if (thirdBG) savedThird = thirdBG.sharedMaterial.GetTextureOffset("_MainTex");
    }
 
    void Move(MeshRenderer mesh, Vector2 savedOffset, float speed)        
    {  
       if (Input.GetKey(KeyCode.D))
        {
            Vector2 offset = Vector2.zero;    
            float tmp = Mathf.Repeat(+(Time.time * speed), 1);
            if (projectMode == ProjectMode.moveY) offset = new Vector2(savedOffset.x, tmp);
            else offset = new Vector2(tmp, savedOffset.y);
            mesh.sharedMaterial.SetTextureOffset("_MainTex", offset);          
        }  
       if (Input.GetKey(KeyCode.A))
         {
           Vector2 offset = Vector2.zero;
           float tmp = Mathf.Repeat(-(Time.time * speed), 1);
           if (projectMode == ProjectMode.moveY) offset = new Vector2(savedOffset.x, tmp);
           else offset = new Vector2(tmp, savedOffset.y);
           mesh.sharedMaterial.SetTextureOffset("_MainTex", offset);
        }    
    }
    void Update()
    {
        if (firstBG) Move(firstBG, savedFirst, firstBGSpeed);
        if (secondBG) Move(secondBG, savedSecond, secondBGSpeed);
        if (thirdBG) Move(thirdBG, savedThird, thirdBGSpeed);
    }
   
    void OnDisable()
    {        
        if (firstBG) firstBG.sharedMaterial.SetTextureOffset("_MainTex", savedFirst);
        if (secondBG) secondBG.sharedMaterial.SetTextureOffset("_MainTex", savedSecond);
        if (thirdBG) thirdBG.sharedMaterial.SetTextureOffset("_MainTex", savedThird);
    }
}

Time.deltaTime;

if (projectMode == ProjectMode.moveY * Time.deltaTime) offset = new Vector2(savedOffset.x, tmp);