Composite round objects like vortexes in After Effects

[aedand61023699]

Hey guys, I have a problem. There doesnt seem to be anything out there teaching you how to composite elements of for example smoke or other stuff, AROUND people or so. I have a 3d smoke vortex in C4D and I want to have it go around my actor in the shot. But I cannot find any tutorials on how to composite elements around other elements from the original footage. The Vortex Cloud is supposed to spin up around the actor and then make them dissapear, I would need help with getting the vortex behind and in front of the actor at the same time, as it is supposed to be spinning around the actor and then close around them. 

Especially with smoke i cant just bruteforce roto it out, cause well, 

[Mylenium]

Nothing to do with AE. You simply need two image sequences that define a front and back. That's entirely up to how you construct your shaders and manage your particle systems to generate a holdout matte and whatever else may be needed.

Mylenium

[aedand61023699]

But what if I have only one single particle emitter that is responsible for the smoke or what if the smoke is supposed to engulf the actor from all sides? That I could still imagine doing, but what if it's only one emitter??

[Mylenium]

I'm not clear what you are asking. There's a million ways to handle this in C4D and it doesn't matter whether you have one emitter or many. Anything from a collision plane set to kill mode to define the cut-off to constructing a special material for the particles using a gradient or something liek the Proximal shader. Of course you could always do things the hard way in AE with masking and keying, but even then you likely end up rendering a different output from C4D e.g. to compensate for opacities adding up. Again, this has very little to do with AE. You need to brush up on your C4D particle skills more than anything else and understand how to create custom render passes or at the very least work with depth buffers and object passes.

Mylenium

[aedand61023699]

I'm only 14 and new to the entire animation business so yeah, I definitely have a lot to learn still 😅

but you seem to be very knowledgeable about C4d already so I have one more question I'd be super happy to have answered: if I have an object that is flying around my scene, how do I have that character fly around my people in the scene? Again something in C4d or is it in ae with roto? 

[aedand61023699]

Oh and well could you perhaps explain to me a bit further how to render the different passes so that I have one big smoke cloud that can be around my actors? 
thaaanks