How can I composite the new shadow catcher that should work with reflections in latest versions of blender?

Question

There are no so many shadow catcher youtube tutorials on blender, and all of them are outdated. I tried using the new shadow catcher that should work with reflections also and couldn't make it look good. I am not good at compositing. So if anyone understand the new shadow catcher that comes with latest versions of blender, please explain how to use it. Thanks!

Answer 1

• Enable Environment and Shadow Catcher in the Light subpanel of the Passes panel of the View Layers Properties tab in the Properties Editor.

  (Properties Editor → View Layers → Passes → Light)

• Select the object you want to be a shadow catcher and enable Shadow in the Ray Visibility subpanel of the Visibility panel of the Object Properties tab in the Properties Editor.

  (Properties Editor → Object → Visibility → Ray Visibility)

• Set up the compositor nodes that I've highlighted in this screenshot:

Note that I am using a compositor denoiser in this screen shot. If you don't want to do that, then connect the Image output of the Render Layers node to the lower input of the Alpha Over node.

Also note that this setup is for Cycles.

The key thing here is that if you want color and reflections you need to multiply the Shadow Catcher and Env pass outputs of the Render Layer and then you need to use that as the Alpha Over input to composite the shadow catcher with the image.

You can add more compositing nodes after the Alpha Over or between the (Denoise) Image and the Alpha Over, of course.

You may find this tutorial useful for more detail.