How to do Minecraft like circular projected shadow?


I want to reproduce “Minecraft Like” shadows for players, but I’m a bit confused about how I could achieve it.
I found the example of these bouncing balls that seems to reproduce most of the logic:

But there is still one thing missing to complete the logic. When the player is on an edge, the shadow is also projected on the next surface progressively, as follows:

I don’t found a way to achieve this with this method. Has anyone any idea how it was done?

I want to use this logic instead of the “traditional ways” to do shadows, for scalability purposes.