How to Prevent UI Clicks in Unity from “Bleeding Through” to 3D Objects Behind Them

Have you ever encountered this annoying issue in Unity? You have a clickable 3D object (using OnMouseDown, raycasting, etc.), and you also have a UI canvas with buttons or interactive elements. When the player clicks a UI button, the 3D object behind it also registers the click — even though the UI is clearly on top!

This happens because Unity’s default input system doesn’t automatically block pointer events from reaching the 3D world when they’re over a UI element.

The Simple Fix

Just add a quick check at the beginning of your click-detection code (whether it’s in OnMouseDown, Update with raycast, IPointerClickHandler, etc.) to ignore the click if the pointer is currently over a UI element.

Here’s the code you need:

C#

// Add this using directive at the top of your script
using UnityEngine.EventSystems;

public class YourClickDetector : MonoBehaviour
{
    // Example using raycast in Update
    void Update()
    {
        // Ignore input if the pointer is over any UI element
        if (EventSystem.current != null && EventSystem.current.IsPointerOverGameObject())
            return;

        // Your normal click/raycast detection code continues here...
        if (Input.GetMouseButtonDown(0))
        {
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            if (Physics.Raycast(ray, out RaycastHit hit))
            {
                if (hit.transform == this.transform)
                {
                    // Your 3D object was clicked!
                    Debug.Log("3D object clicked!");
                }
            }
        }
    }

    // Or if you're using OnMouseDown
    private void OnMouseDown()
    {
        // === Prevent click if user is clicking UI ===
        if (EventSystem.current != null && EventSystem.current.IsPointerOverGameObject())
            return;

        Debug.Log("3D object properly clicked (no UI interference)!");
    }
}

That’s it! The line:

C#

if (EventSystem.current != null && EventSystem.current.IsPointerOverGameObject())
    return;

tells Unity: “If the mouse/touch is currently over any UI element that belongs to the EventSystem, just ignore this input.”

Bonus Tips

• This works for both mouse and touch input.
• For touch devices, you can also use Input.GetTouch(0).fingerId with IsPointerOverGameObject(fingerId) if you need more precision with multi-touch.
• Make sure your Canvas is set to “Screen Space – Overlay” or “Screen Space – Camera” and has a Graphic Raycaster component (it does by default).

With just these few lines, your UI buttons will work perfectly without accidentally triggering the 3D objects behind them.

Hope this helps someone out there! Happy developing!