How to properly draw a mesh using CommandBuffer.DrawMesh?

I’ve seen the examples provided by Unity, but I must be missing something because I’m not getting the results I expect.

In my initial test, I’m simply trying to draw a non-moving, user defined mesh, with a user defined material. (New scene, new project). Unfortunately, while I can get the mesh to show up on camera, it looks like it has no lighting on it, as it’s completely black. (Lighting not applied is confirmed; tested using unlit shader materials, which DO show up properly.)
86829-commandbufferdrawnmesh.png

The main question is: how do I fix this script to allow the material to show up properly, with lighting?

(Note on script: it is necessary to add (but not configure) a renderer component, in order for OnWillRenderObject to be executed. I used a meshRenderer, without a meshfilter. Can this be avoided, if I want to move the mesh?)

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
[ExecuteInEditMode]
public class AllCameraCommandRender : MonoBehaviour
{
    
    List<int> assignedCameraGUIDs;
    public Mesh meshToRender;
    public Material matierialForMesh;
    CommandBuffer cb;
    private void Start()
    {
        if (assignedCameraGUIDs == null) assignedCameraGUIDs = new List<int>();
        else assignedCameraGUIDs.Clear();
    }
    public void OnWillRenderObject()
    {
        if (assignedCameraGUIDs == null) assignedCameraGUIDs = new List<int>();
        Camera cam= Camera.current;
        int id = cam.gameObject.GetInstanceID();
        if (!assignedCameraGUIDs.Contains(id))
        {
            if (cb == null)
            {
                Matrix4x4 M = transform.localToWorldMatrix;
                //Matrix4x4 V = cam.worldToCameraMatrix;
                //Matrix4x4 P = GL.GetGPUProjectionMatrix(cam.projectionMatrix, false);
                //Matrix4x4 I = Matrix4x4.identity;
                cb = new CommandBuffer();
               // cb.SetRenderTarget(BuiltinRenderTextureType.CameraTarget);
                cb.DrawMesh(meshToRender, M, matierialForMesh);
            }                                                                              
            cam.AddCommandBuffer(CameraEvent.BeforeForwardOpaque, cb);
           // cam.AddCommandBuffer(CameraEvent.BeforeLighting, cb);
            assignedCameraGUIDs.Add(id);
        }
    }
}

I was also experimenting with changing the CameraEvent: I tried to use BeforeLighting, like the decals example does, but this change prevented the object from being visible at all. Why is that? (I saw a post in the forum indicating that CameraEvent might be using the matrix differently, so I experimented with some variants: none, except the transform.localToWorldMatrix, seemed to work- but thats why they are in the code above.)

I also tried using the SetRenderTarget command, but this seemed to have no effect. I assume that if I make no changes to the target, the default render target will be the BuiltinRenderTextureType.CameraTarget. Is that correct?

I have found a solution.

It’s a Unity issue and they provide a solution around this. (Took me a while to find the solution)

—What is the problem—
Unity doesn’t assign the ‘SH coefficients’ to the target material and that leads to no ambient lighting.

—How to solve it—
Calculate it in CPU once → Assing it to ‘MaterialPropertyBlock’, → Assing that to the material.

Github link for the solution example

Funny, according to this link you just do:

cb.DrawMesh(meshToRender, M, matierialForMesh, 0, 0);