ClickRay.cs

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

public class DrawOb : MonoBehaviour
{
    private Camera camera;
    public GameObject InstantiatedOb;
    void Start()
    {
        camera = Camera.main;
    }

    // Update is called once per frame
    void Update()
    {
        Click();
    }

    private void Click()
    {
        if (Input.GetMouseButton(0))
        {
            Ray ray = new Ray();
            RaycastHit hit = new RaycastHit();
            ray = camera.ScreenPointToRay(Input.mousePosition);

            if (Physics.Raycast(ray.origin, ray.direction, out hit, 10) )
            {
                Debug.Log(ray.GetPoint(10));
                Vector3 pos = new Vector3(ray.GetPoint(10).x, ray.GetPoint(10).y, -5);
                Instantiate(InstantiatedOb, pos, Quaternion.identity);
            }
            else
            {
                Debug.Log(ray.GetPoint(10));
                Vector3 pos = new Vector3(ray.GetPoint(10).x, ray.GetPoint(10).y, -5);
                Instantiate(InstantiatedOb, pos, Quaternion.identity);
            }

        }

    }


}