Expose sorting layer in MeshRenderer inspector, for rendering on top of sprites

MeshRendererSortingEditor.cs

using UnityEngine;
using UnityEditor;
using System.Linq;

/// This just exposes the Sorting Layer / Order in MeshRenderer since it's there
/// but not displayed in the inspector. Getting MeshRenderer to render in front
/// of a SpriteRenderer is pretty hard without this.
[CustomEditor(typeof(MeshRenderer))]
public class MeshRendererSortingEditor : Editor
{

    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();

        MeshRenderer renderer = target as MeshRenderer;


        var layers = SortingLayer.layers;

        EditorGUILayout.BeginHorizontal();
        EditorGUI.BeginChangeCheck();
        int newId = DrawSortingLayersPopup(renderer.sortingLayerID);
        if(EditorGUI.EndChangeCheck()) {
            renderer.sortingLayerID = newId;
        }
        EditorGUILayout.EndHorizontal();

        EditorGUILayout.BeginHorizontal();
        EditorGUI.BeginChangeCheck();
        int order = EditorGUILayout.IntField("Sorting Order", renderer.sortingOrder);
        if(EditorGUI.EndChangeCheck()) {
            renderer.sortingOrder = order;
        }
        EditorGUILayout.EndHorizontal();

    }

    int DrawSortingLayersPopup(int layerID) {
        var layers = SortingLayer.layers;
        var names = layers.Select(l => l.name).ToArray();
        if (!SortingLayer.IsValid(layerID))
        {
            layerID = layers[0].id;
        }
        var layerValue = SortingLayer.GetLayerValueFromID(layerID);
        var newLayerValue = EditorGUILayout.Popup("Sorting Layer", layerValue, names);
        return layers[newLayerValue].id;
    }

}

// This is free and unencumbered software released into the public domain.
// 
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// distribute this software, either in source code form or as a compiled
// binary, for any purpose, commercial or non-commercial, and by any
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// of this software dedicate any and all copyright interest in the
// software to the public domain. We make this dedication for the benefit
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// software under copyright law.
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I remade it by inheriting the internal class MeshRendererEditor to keep the default functionality and compability with prefab, multi-edit, and undo/redo. Also I added support for SkinnedMeshRenderer and included installation as a UPM package.
https://github.com/qwe321qwe321qwe321/Unity-ExposeSortingLayerEditor