Instantiating objects to screen on android

Questions & Answers
1

I want to instantiate object to screen where I touch. I’m testing this on the android, but it doesn’t instantiate anything. Here is the code:

using UnityEngine;
using System.Collections;
using System;

public class TouchInputController : MonoBehaviour {

	public bool showDebug = true; // if true
	public GameObject particle;
	
	private Vector3 _touchLocation;
	private String _touchState;
	private Vector3 _rayPosition;
	private String _error;
	
	// Update is called once per frame
	void Update () {
	
		if(Input.touchCount >= 1) {
			_touchState = Input.GetTouch(0).phase.ToString();
			_touchLocation = Input.GetTouch(0).position;
			
			Ray ray = Camera.main.ScreenPointToRay(_touchLocation);
			_rayPosition = ray.origin;
			_rayPosition.z = 0;
			
			try{
				Instantiate(particle, _rayPosition, Quaternion.Euler(new Vector3(0.5f, 0.5f,0.0f)));
				_error = "None";
			}
			catch(Exception e) {
				_error = e.ToString();
			}
		}
		else 
			_touchState = "None";
	}
	
	
	void OnGUI()
	{
		if (!showDebug)
			return;
			
		int fontSize = 20;
		
		float guiWidth = Screen.width * 0.4f;  
		float guiHeight = 300;
		float guiPoxX = Screen.width * 0.01f;
		float guiPoxY = Screen.height * 0.03f;

		float t_itemHeight = fontSize * 1.5f;
		float t_itemY = guiPoxY + 5.0f;
		float t_itemX = guiPoxX + 5.0f;
		
		GUI.skin.label.fontSize = fontSize;
		
		// Make a background box, 
		// static void Box(Rect position, string text);
		GUI.Box(new Rect(guiPoxX, guiPoxY, guiWidth, guiHeight), "");
				
		// get the number of boxes to spawn
		GUI.Label(new Rect(t_itemX, t_itemY, guiWidth, t_itemHeight), 
				String.Format("touch count: {0}", Input.touchCount));
		t_itemY += t_itemHeight;
			
		// get the number of boxes to spawn
		GUI.Label(new Rect(t_itemX, t_itemY, guiWidth, t_itemHeight), 
			String.Format("Touch Location: x:{0} y:{1}", _touchLocation.x, _touchLocation.y));
		t_itemY += t_itemHeight;
		
		// get the number of boxes to spawn
		GUI.Label(new Rect(t_itemX, t_itemY, guiWidth, t_itemHeight), 
		          String.Format("touch phase: {0}", _touchState));
		t_itemY += t_itemHeight;	
		
		// get the number of boxes to spawn
		GUI.Label(new Rect(t_itemX, t_itemY, guiWidth, t_itemHeight), 
		          String.Format("Ray Location: x:{0} y:{1}", _rayPosition.x, _rayPosition.y));
		t_itemY += t_itemHeight;		
		
		// get the number of boxes to spawn
		GUI.Label(new Rect(t_itemX, t_itemY, guiWidth, t_itemHeight), 
		          String.Format("Errors: {0}", _error));
		t_itemY += t_itemHeight;
		
	}

}
2

Here’s a quick example of instantiate on touch position.

using UnityEngine;
using System.Collections;

public class TouchInstantiate : MonoBehaviour {

	public GameObject thing; //Whatever you want to instantiate

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
		if (Input.touchCount > 0) {
			//This returns the screen coordinates of the touch
			Vector2 touchPos = Input.GetTouch(0).position;
			//Since touchPosition is in screen coordinates, you must convert it to world position by using ScreenToWorldPoint
			Vector3 worldpos = Camera.main.ScreenToWorldPoint(touchPos); 
			//Once you have the world point, you can instantiate
			Instantiate(thing, worldpos, Quaternion.identity);
		}
	}
}

For future reference, check the forums (or the documentation) as there are a lot of similar questions.