Drawing game objects at the mouse cursor

How do I draw a prefab exactly where my mouse is right now? I could really use the code to do that because I've been on it for like a day and still got nothing.

 

You'd probably want to use ScreenToWorldPoint and mousePosition.

 

The thing is, I'm totally new to Unity and I was hoping for more of a step-by-step solution.

 

This code should show you how to place a prefab at the mouse pointer. Read all the comments to understand what is going on.

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class ExampleClass : MonoBehaviour {
5.  
6.     public GameObject prefabObj;
7.  
8.     //places a prefab at the mouse position
9.     void PlacePrefab() {
10.         //First you will want to get the mouse position using Input.mousePosition
11.        Vector2 mousePos = Input.mousePosition;
12.        //Next you will want to convert the Vector2 mouse position to a Vector3 world position
13.        Vector3 worldPos = Camera.main.ScreenToWorldPoint (new Vector3 (mousePos.x,mousePos.y,Camera.main.nearClipPlane));
14.        //Finally you will want to place your prefab
15.        Instantiate(prefabObj, worldPos, Quaternion.identity);
16.     }
17.  
18.     //Places a prefab on mouseup
19.     void OnMouseUp() {
20.         PlacePrefab();
21.     }
22. }