Hasta La Motion!

Sorry, some tedious questions coming up, so please indulge me. I’ve looked at show reels and researched definitions but I’m none the wiser.

I keep saying I want to be an VFX Compositor but if I really think about it, I’m unsure where a Compositor job starts and ends.

If for example you have a close-up shot of a foot stepping off a kerb, and you want to make that foot look like it’s stepping in a puddle, and you want the puddle splash to be in slow motion. Who would create the slow motion water?

What about someone walking through glass with no glass there previously? Who creates the window and the subsequent broken glass?

What about a bullet hole needed in a wall or body?

And finally. What about adding a lamp post or a park bench?

Is the Compositors role just to combine all the elements and they’re given everything by an VFX Artist or is there some CGI creation involved for the Compositor?

I’m talking about on a high end commercial or film work where there are lots of bodies and departments working on a project.

Thank you.