Simple script to correct sorting z-sorting for Unity games using both 2d SPrites and 3D-meshes. Adds a property for the mesh that lets you specify its sorting layer

OverrideSortingLayer.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// Used to set Sorting Layer for 3D meshes, so they can Z-sort
/// correctly when used with 2D Sprites.
/// </summary>
public class OverrideSortingLayer : MonoBehaviour
{
    public string sortingLayerName;
    public int sortingOrder;

    private Renderer usedRenderer;

    // Start is called before the first frame update
    void Start()
    {
        if (!string.IsNullOrEmpty(sortingLayerName))
        {
            usedRenderer = GetComponent<Renderer>();
            usedRenderer.sortingLayerName = sortingLayerName;
            usedRenderer.sortingOrder = sortingOrder;
        }
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}