Unity how to remove duplicate objects?

Question

Game development

When I press W, only the object is duplicated (the player, but only visually), and when I attached the camera, the surrounding objects themselves were duplicated!
Here is the code

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class moving : MonoBehaviour {
  public GameObject obj;
  private float speed = 5f;
  private Rigidbody2D rb;
  private Vector3 directionY;

  private void Awake(){
    rb = GetComponent <Rigidbody2D> ();
  }

  private void Update () {
    if (Input.GetKey (KeyCode.W)) {
      directionY = transform.up;
      transform.position = Vector3.MoveTowards (transform.position + directionY, transform.position,speed * Time.deltaTime);
    } else if (Input.GetKey (KeyCode.D)) {
      
    }

  }
}

Answer 1

You have "Depth only" or "Don't Clear" on your camera 's clearFlags , so all your objects draw plumes. Install Solid Color or Skybox, then there will be no such problem.