GraphicRaycaster.Raycast

Description

Determines if the cursor is over a Graphics element in the Scene. See: BaseRaycaster.

Use this to determine if the cursor is over a Graphics element in the Scene. It accepts the mouse pointer event data as a parameter. Make sure you have an EventSystem in your hierarchy. If you don’t, go to Create >UI >Event System. Some common uses of this include: setting up your own custom UI system; telling when you hover over Text or Images which aren’t automatically selectable; UI click and drag operations; and many more.

//Attach this script to your Canvas GameObject.
//Also attach a GraphicsRaycaster component to your canvas by clicking the Add Component button in the Inspector window.
//Also make sure you have an EventSystem in your hierarchy.

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections.Generic;

public class GraphicRaycasterRaycasterExample : MonoBehaviour
{
    GraphicRaycaster m_Raycaster;
    PointerEventData m_PointerEventData;
    EventSystem m_EventSystem;

    void Start()
    {
        //Fetch the Raycaster from the GameObject (the Canvas)
        m_Raycaster = GetComponent<GraphicRaycaster>();
        //Fetch the Event System from the Scene
        m_EventSystem = GetComponent<EventSystem>();
    }

    void Update()
    {
        //Check if the left Mouse button is clicked
        if (Input.GetKey(KeyCode.Mouse0))
        {
            //Set up the new Pointer Event
            m_PointerEventData = new PointerEventData(m_EventSystem);
            //Set the Pointer Event Position to that of the mouse position
            m_PointerEventData.position = Input.mousePosition;

            //Create a list of Raycast Results
            List<RaycastResult> results = new List<RaycastResult>();

            //Raycast using the Graphics Raycaster and mouse click position
            m_Raycaster.Raycast(m_PointerEventData, results);

            //For every result returned, output the name of the GameObject on the Canvas hit by the Ray
            foreach (RaycastResult result in results)
            {
                Debug.Log("Hit " + result.gameObject.name);
            }
        }
    }
}