Any tips on how to get this to work in 2021 LTSC?

[Esildor]

After upgrading the project to 2021.3.0f1, all my materials on the Pixel layer are transparent.

[randomuserhi]

First select the main camera in the scene and turn off Depth Texture under the rendering options. (You may also do this in URP settings and then change the Depth Texture option on the main camera to use pipeline settings):

As for why enabling the Depth Texture ruins the effect, I don't know, if someone else can explain, would be nice ¯\_(ツ)_/¯.

Next go BasicFeaturePass.cs and change line 21 from:

static int cameraID = Shader.PropertyToID("_CameraColorTexture");

to

static int cameraID = Shader.PropertyToID("_CameraColorAttachmentA");

This fixes it because otherwise the render pass is drawing to a texture that doesn't exist or one that is not being displayed on screen.

Because unity's naming convention may change from time to time, you can check what the shader property should be by going to the frame debugger under window > analysis > frame debugger and looking at what texture the transparency, opaque draw calls all write to:

[Esildor]

Thanks dude! This both fixed this issue and was super informative. You're the real MVP 💕❤️