How do live action cgi characters work?

Question

To be clear, im not referring to characters where you can have a human actor play the part and then edit the animated model onto them. For characters with abnormal body types or shapes that cant be played by an actor, how is pre-edit filming done?

In: 2

Answer 1

In some cases, they literally just attach a tennis ball to a stick and tell the actor, “Here’s where his face will be,” and the actor just goes about the scene as normal, pretending it’s a giant slug monster or whatever