UNITY - Select object with Raycast - Works on Windows, errors onWebGL (TouchScreen)

Question

I want to select an object on the scene touching it on the screen. I have made this code and it perfectly works on Unity player or when i compile the application for Windows. When i compile for WebGL i have strange behaviours (tested on Firefox/Chrome)

The error i get is that , if i keep my finger pressed on the object, i get multile continuous click instead of a single one even if i'm using TouchPhase.Began. Someone knows how to fix this problem? Is a known issue?

Here's my code

using UnityEngine;
using System.Collections.Generic;
using System.Xml.XPath;
using UnityEngine.UI;


public class RaycastObjHit : MonoBehaviour
{


private GameObject working_object;
private GameObject touchedObject;


void Update()
{
    if (Input.touchCount == 1 && Input.GetTouch(0).phase == TouchPhase.Began)
    {
        Ray ray = Camera.current.ScreenPointToRay(Input.GetTouch(0).position);
        RaycastHit hit;   

        if (Physics.Raycast(ray, out hit))
        {
            string ObjHitName = hit.transform.name;
            Debug.Log(hit.transform.name);
            if (hit.collider != null)
            {
                touchedObject = hit.transform.gameObject;

                if (touchedObject.GetComponent<Renderer>().material.color != Color.red )
                {
                    changeColor(touchedObject.transform.name, Color.red);   
                }else{
                    changeColor(touchedObject.transform.name, Color.green);   
                }

            }
                Debug.Log("Touched " + touchedObject.transform.name);
         }
     }

}
public void changeColor(string objId, Color color)
{
    working_object = GameObject.Find(objId);
    working_object.GetComponent<Renderer>().material.color = color;
}

}

score 1 · Accepted Answer · answered Nov 28 '18 at 15:54

If someone want to know how i "solved" the problem here's my code. Is a simple workaround that is using a boolean to control if i'm keep pressing the monitor during the same event. I repeat,is only a workaround to solve this "incompatibility" with WebGL

using UnityEngine;
using System.Collections.Generic;
using System.Xml.XPath;
using UnityEngine.UI;


public class RaycastObjHit : MonoBehaviour
{

private GameObject working_object;
private GameObject touchedObject;
private bool touchBegan = false;

void Update()
{
    if (Input.touchCount == 1)
    {
        if (Input.GetTouch(0).phase == TouchPhase.Began && !touchBegan)
        {
            touchBegan = true;
            Ray ray = Camera.current.ScreenPointToRay(Input.GetTouch(0).position);
            RaycastHit hit;

            if (Physics.Raycast(ray, out hit))
            {
                string ObjHitName = hit.transform.name;
                Debug.Log(hit.transform.name);
                if (hit.collider != null)
                {
                    touchedObject = hit.transform.gameObject;

                    if (touchedObject.GetComponent<Renderer>().material.color != Color.red)
                    {
                        changeColor(touchedObject.transform.name, Color.red);
                    }
                    else
                    {
                        changeColor(touchedObject.transform.name, Color.green);
                    }

                }

                Debug.Log("Touched " + touchedObject.transform.name);
            }
        } else if (Input.GetTouch(0).phase == TouchPhase.Ended && touchBegan){
            touchBegan = false;
        }
    }

}
public void changeColor(string objId, Color color)
{
    working_object = GameObject.Find(objId);
    working_object.GetComponent<Renderer>().material.color = color;
}
}

score 0 · Answer 2 · answered Nov 28 '18 at 11:55

0

That's not the way you do this in 2018 (the year, not the Unity version). Put a PhysicsRaycaster on your camera, add in an EventSystem, then Implement IPointer***Handler (Down, Up, Enter, Exit, Click, you name it).

answered Nov 28 '18 at 11:55

Arshia001

1,854
14
19

How can you say this?Can you point to some articles/tutorial about this "new way" of implementing touch applications? I mean, i'm almost a newbie of Unity but i did not found anything specific about best practice in creating applications that use touch screens.With only TouchPhase i have all i need for an application on touch screens. I think that my problem is strictly bound to WebGL & TouchScreens – Nic Nov 28 '18 at 15:49
1

TouchPhase a bit too low-level and only meaningful on touch platforms. And besides, you'd probably be reinventing the wheel. Here's the documentation for IPointerClickHandler, and don't forget to also put a physics raycaster on your camera: https://docs.unity3d.com/ScriptReference/EventSystems.IPointerClickHandler.html – Arshia001 Nov 29 '18 at 10:18

UNITY - Select object with Raycast - Works on Windows, errors onWebGL (TouchScreen)

2 Answers2