Learning VFX Compositing In Real-Time - Sources?

Hello I’m a filmmaker and am interested in learning more about the techniques, software and hardware currently available to accomplish VFX Compositing In Real-Time.

[Most specifically live action in foreground composited with 3D gaming, film or stills as background plates to simulate realistic environments on 2D film or digital video]

Can anyone here advise as to online tutorials, books and online courses?

Thank you in advance

HorrorMaven FIlms - Hollywood, CA.