Using Unity New GUI system, Will first need to create a GUI element using Prefab and save under Resources Folder. Then upon collision trigger, instantiate the GUI prefab and display onGUI
using UnityEngine; using System.Collections; using UnityEngine.UI; public class PlayerContact : MonoBehaviour { bool ToggleGUI = false; bool isCreated = false; // Use this for initialization void Start () { //Resources.Load ("PopupMsg"); } // Update is called once per frame void Update () { } void OnTriggerEnter(Collider other) { if (other.gameObject.CompareTag ("Player")) { //Debug.Log ("Detected"); ToggleGUI = true; } } void OnGUI(){ if (ToggleGUI == true) { if(!isCreated){ GameObject msg = (GameObject)Instantiate(Resources.Load("PopupMsg")); isCreated = true; } } } }