Ordered raycaster for casting against 3D Physics components. https://twitter.com/shanecelis/status/1146822575978373120

OrderedPhysicsRaycaster.cs

/* Original code[1] Copyright (c) 2019 Shane Celis[2]
   Licensed under the MIT License[3]

   This comment generated by code-cite[4].

   [1]: https://gist.github.com/shanecelis/7881b64ce07ee399f9c2928d977de8c6
   [2]: https://github.com/shanecelis
   [3]: https://opensource.org/licenses/MIT
   [4]: https://github.com/shanecelis/code-cite
*/

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

namespace UnityEngine.EventSystems {
/// <summary>
/// Simple event system using ordered physics raycasts.
/// </summary>
[AddComponentMenu("Event/Ordered Physics Raycaster")]
[RequireComponent(typeof(Camera))]
/// <summary>
/// Ordered raycaster for casting against 3D Physics components.
/// </summary>
public class OrderedPhysicsRaycaster : PhysicsRaycaster {

  [Header("Set sorting order on raycasts.")]
  public int sortingOrder = 1;

  protected OrderedPhysicsRaycaster() { }

  public override void Raycast(PointerEventData eventData, List<RaycastResult> resultAppendList) {
    int initialCount = resultAppendList.Count;
    base.Raycast(eventData, resultAppendList);
    for (int i = initialCount; i < resultAppendList.Count; i++) {
      // Do our struct dance do-si-do.
      var raycastResult = resultAppendList[i];
      raycastResult.sortingOrder = sortingOrder;
      resultAppendList[i] = raycastResult;
    }
  }
}
}