Blocking Physics Raycasts with the UI?

I use raycasts to determine hit objects and object selection in our game. I want these to be blocked by UI elements. Before I had a crude form of that where I just excluded rects of the screen, though with a non-rectangle shaped UI that's pretty difficult.

I want to have physics raycasts NOT go through UI objects, can this be done? My initial thought it adding colliders to the UI objects, though I'm not sure if the colliders will scale with elements based on screen size.

Note: Canvas Group does not apply to physics.raycast

 

There is a way to detect that you have clicked the UI via http://docs.unity3d.com/ScriptReference/EventSystems.EventSystem.IsPointerOverGameObject.html
While oddly worded in this case a game object is an event system object or new GUI component.

So in the beginning of your code that fires when the raycast hits, you ask if the pointer is over a UI component and abort the method.

 

FYI its worded like that as it will return true if its over any EvenSystem controlled element. So if you have a physics raycaster and the mouse is over a physics collider it will be true.

 

Ooh, I'm worried that my suggestion won't work for him as he is using physics raycasts. Is there anyway in code to detect the new UI and no other systems?

 

@phil-Unity This question has come up a few times.
Is there anyway to block normal raycasting through the UI canvas or UI object?

So preventing Physics.Raycast from passing through a Canvas?

 

No there is no way to do that unfortunately just with the extra check

 

Fair enough @phil-Unity Still need to come up with an answer to that, either with layers or (as some have found) adding UI scripts to 3D objects

 

I use this link to solve it.

https://answers.unity.com/questions/1079066/how-can-i-prevent-my-raycast-from-passing-through.html

 

A workaround is to create a CustomInputModule to get buttons' PointerEventData, there you find pointerCurrentRaycast who tells you which BaseRaycaster was used in it - so you just check it.

Here's a CustomStandaloneInputModule

Code (CSharp):

1. using UnityEngine.EventSystems;
2.  
3. /*  /class CustomStandaloneInputModule
4. *  /brief A StandaloneInputModule with access to buttons' PointerEventData and RaycasterModule checking
5. */
6. public class CustomStandaloneInputModule : StandaloneInputModule
7. {
8.     /// <summary>
9.     /// Returns current PointerEventData
10.     /// </summary>
11.     public PointerEventData GetPointerData(int pointerId = kMouseLeftId)
12.     {
13.         PointerEventData pointerData;
14.  
15.         m_PointerData.TryGetValue(pointerId, out pointerData);
16.         if (pointerData == null) pointerData = new PointerEventData(EventSystem.current);
17.  
18.         return pointerData;      
19.     }
20.  
21.     /// <summary>
22.     /// Returns true if current raycast has hit an game object using Raycaster T
23.     /// </summary>
24.     public bool IsPointerOverGameObject<T>(int pointerId = kMouseLeftId, bool includeDerived = false) where T : BaseRaycaster
25.     {
26.         if(IsPointerOverGameObject(pointerId))
27.         {
28.             PointerEventData pointerEventData;
29.             if (m_PointerData.TryGetValue(pointerId, out pointerEventData))
30.             {
31.                 if (includeDerived)
32.                 {
33.                     return pointerEventData.pointerCurrentRaycast.module is T;
34.                 }
35.                 else
36.                 {
37.                     return pointerEventData.pointerCurrentRaycast.module.GetType() == typeof(T);
38.                 }
39.             }
40.         }
41.         return false;
42.     }
43. }

Usage example:

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3. using UnityEngine.EventSystems;
4.  
5. public class MoveControl : MonoBehaviour
6. {
7.     CustomStandaloneInputModule inputModule;
8.  
9.     private void Awake()
10.     {
11.         inputModule = FindObjectOfType<CustomStandaloneInputModule>();
12.     }
13.  
14.     private void Update()
15.     {
16.         if (inputModule.IsPointerOverGameObject<PhysicsRaycaster>())
17.         {
18.             print("Over 3D Object!");
19.         }
20.         else if (inputModule.IsPointerOverGameObject<Physics2DRaycaster>())
21.         {
22.             print("Over 2D Object!");
23.         }
24.         else if (inputModule.IsPointerOverGameObject<GraphicRaycaster>())
25.         {
26.             print("Over UI Object!");
27.         }
28.     }  
29. }

 

For me, in the case of having a Physics raycaster attached to the camera the most simple and cleanest solution to prevent the raycaster from firing trough canvas (as it will fire in the case of having a physics raycaster on camera) was to simply check the eventsystem for a selected UI piece.

Code (CSharp):

1. EventSystem.current.currentSelectedGameObject != null

 

Unfortunately, for me it's worked only if I use GraphicRaycaster.
Problems began when I add PhysicsRaycaster to the camera.
Now IsPointerOverGameObject() always returns true, if pointer over UI or physic objects.

 

Sorry for resurrecting, just want to post what worked for me. I'm using both physic and graphic raycasters.

Code (CSharp):

1. RaycastHit theHit;
2.  
3. if(Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out theHit, Mathf.Infinity)){
4.  
5. // success on raycastHit stored on theHit object
6.  
7.      if(  theHit.collider.tag == "expectedTag" && !EventSystem.current.IsPointerOverGameObject())
8.        {
9.           // will only get here if theHit object is being raycasted and no UIElement (on the UI layer) is             being touched by the mouse pointer
10.        }
11. }
12.  

Note that EventSystem.current.IsPointerOverGameObject() is a Method, is the most recommended option IMO

 

1. Add a button at the bottom of the canvas, uncheck image to make the button invisible;
2. In Update method, check `EventSystem.current.currentSelectedGameObject != null`
done

 

I am having one heck of a time getting my XR rig to move from scene to scene with working UI in each. I have made a prefab which includes the XR Rig, Event System with XRUI input module, as well as the XR interaction module. The prefab has this script attached.
public class DontDestroy : MonoBehaviour
{
public static DontDestroy instance;
void Start()
{
if (instance == null)
{
instance = this;
DontDestroyOnLoad(this);
}
else
{
Destroy(gameObject);
}
}
}
I can use the UI I have attached to my wrists to move from scene to scene. However, the XR Raycast Interactor raycasts will not move anywhere but within the canvas and whenever I return to Scene(0) from scene (1) the entire rig shuts down leaving only the camera mobile. Here's a vid of what it looks like:

 

Thank you ,Thats what I was looking for

 

Same here, infinite thanks, in my case I only had to add && !EventSystem.current.IsPointerOverGameObject() to my check. Most simple solution, no lengthy code to write.

 

this worked for me, using a physics raycast.

 

Code (CSharp):

1. private bool DefineOnUI()
2.     {
3.         //Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
4.         if (EventSystem.current.IsPointerOverGameObject())
5.         {
6.             Debug.Log("Clicked on the UI");
7.             return true;
8.         }
9.         else
10.         {
11.             return false;
12.         }
13.     }

for future reference