Instantiate ground/enemies

Questions & Answers
1

I’m making a 2D side scroller game, and I’m trying to instantiate the pieces of ground in front of character, and to destroy them after a few seconds, but I don’t know how to do.
This code I use for the enemies and for the ground, but they are instantiated sometimes up, and sometimes down. How can I fix it and instantiate both in the same X position?
I’m new in this.

(Sorry bad english! Hope you understand!)

using UnityEngine;
using System.Collections;

public class SpawnScript : MonoBehaviour {

	public GameObject[] obj;
	public float spawnMin = 6f;
	public float spawnMax = 7f;

	// Use this for initialization
	void Start () 
	{
		Spawn ();
	}
	
	void Spawn () 
	{
		Instantiate(obj[Random.Range (0, 0)], transform.position, Quaternion.identity);
		Invoke ("Spawn", Random.Range (spawnMin, spawnMax));

	}
}
2

I am guessing that the SpawnScript is on your player. You are using transform.position and so it takes the y value of your player too.
To fix this replace the transform.position with new Vector3 (x, y, z).
x is your x value, y should be the y value that you want and z should be 0.

if you want to instantiate your objects in front of the player you should do something like transform.position.x + 2f for the x value. Adjust the value to be what you need.

To destroy the ground you can do something like this:

void Spawn () 
{
    GameObject ground = (GameObject)Instantiate(obj[Random.Range (0, 0)], new Vector3 (x, y, z), Quaternion.identity);   // Cast it as a GameObject and making it a variable

    StartCoroutine (DestroyGround (ground));                                                                             // here we are calling the DestroyGround method

    Invoke ("Spawn", Random.Range (spawnMin, spawnMax));
}

IEnumerator DestroyGround (GameObject ground) {
    yield return new WaitForSeconds (s);                // s should be the time after the ground is destroyed
    Destroy (ground);                                   // here we destroy the ground
}