- Home /
EventSystem - all touches have the same ID
I've been working on a UI joystick with 4.6's UI system. Everything works fine, until I'm multi touching the screen. The EventSystem registers the second finger with the same pointerId as finger one. I need to be able to get the individual finger ID's, or pointerId's to be able to filter out unwanted touches.
How do I go about and get the correct pointerId's from the EventSystem?
Here's a tiny excerpt:
using UnityEngine;
using UnityEngine.EventSystems;
using System.Collections;
public class UI_Joystick : MonoBehaviour, IPointerUpHandler, IDragHandler, IPointerDownHandler {
public void OnTouchDrag(PointerEventData eventData)
{
var touchId = eventData.pointerId;
Debug.Log(touchId); // No matter how many fingers I touch down on the object, I will always get a pointerId of -1.
}
}
Edit: When printing the touchId and position of the finger, you can see the big position difference when I touch the screen with a second finger, but still with the same id: (eventData.pointerId + " >> " + eventData.position)
-1 >> (70.3, 85.3)
-1 >> (70.0, 85.3)
-1 >> (187.2, 112.4)
(Last entry is where I touch the screen with a second finger, outside of the UI element)
Did you try toggling the options on the Touch controller module? Something about making it function with pc. Similarly the Standalone input controller has a similar box to make it function on mobile.
See if this does anything for you.
Answer by Bongmo · Oct 04, 2015 at 09:26 AM
It has only "-1" on PC. On a mobile device, it's different.
Answer by hippogames · Feb 17, 2017 at 09:33 AM
The same issue. Hope it's a Unity bug. Anyway, here is my workaround:
public void OnPointerDown(PointerEventData eventData)
{
var touches = Input.touches.Where(i => i.position == eventData.position).ToList();
var touchId = touches.Any() ? touches[0].fingerId : eventData.pointerId;
}
Your answer
![](https://koobas.hobune.stream/wayback/20220613182940im_/https://answers.unity.com/themes/thub/images/avi.jpg)
Follow this Question
Related Questions
Input registering random touches 1 Answer
4.6 UI Change what 'Spacebar' is doing by default 1 Answer
Holding down UI Button and shooting raycast from touch position doesn't work simultaneously:(( 0 Answers
EventSystem causes a NullRef error on restarting a level 1 Answer
Detect touches on ui element 1 Answer