I'm trying to learn how to do this to save on render times during animation in Blender 2.81.
I want to use this on a project that will have moving characters, moving camera, etc. Everything works fine except the shadows. I just don't understand how to composite them in.
In this scene I'm using a z-combine to blend both the BG and the object into one scene, the problem is that the object doesn't cast any shadow. I tried using a shadow catcher and a shadow pass and nothing.
Tutorials are useless since they for old blender versions and end up leaving me confused.
How can I combine the shadows? It's all I need to proceed with rendering my animation.
Blend file here: