CreateSmallCube.cs

// For use with the holographic projection tutorial at www.sbromberg.co
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CreateSmallCube : MonoBehaviour {

    public Transform cubeParent;
	
	void Update () {

        if (Input.GetKeyDown(KeyCode.Space))
        {
            GameObject smallCube = GameObject.CreatePrimitive(PrimitiveType.Cube);
            smallCube.transform.position = transform.position;
            smallCube.transform.localScale = 0.1f*Vector3.one;
            smallCube.transform.parent = cubeParent;
        }
	}
}