Live rotoscoping software (bonus: with reaction to sensor input)

Question

Here's the setup I would like to achieve / the UX I am thinking of having in the end:

1. Let there be a canopy swing with three seats in front of a green screen.
2. Any seat is equipped with a sensor, telling me if someone occupies the seat or not.
3. Sensors tell me the current deflection of the swing.
4. I have a camera set up in front of the swing delivering a live video feed into my computer.
5. I have three different 3D modeled characters (people), for example in a game engine. These can programmatically move around in the scene and "sit" on the swing.

Depending on the number of available seats, whenever at least one person sits down on the swing, I would like to live rotoscope-in the missing number of 3D actors (one real person = two 3D actors, two real persons = one 3D actor, three real persons = no 3D actor).

Is there such a software/software bundle/known software setup to achive this?

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Research so far:

1. Adobe After Effects seems to be post-production only, ie. non-live.
2. Silhouette FX - ditto.
3. DAZ 3D. Possible candidate, but the manufacturer never answered my emails asking if the above can be achieved.
4. Blender. Can do my 3D characters but doesn't have any rotoscoping functions.

Answer 1

You seem to be a little confused on what "rotoscope" means, or I'm not understanding the question here. Rotoscoping is tracing an outline of a subject in a video, for purpose of masking or animating. What you seem to be describing here is compositing, which you'll find is a lot easier to research. You may want to look into how to composite 3D characters from a game engine (say, Unreal Engine 4) into a live video scene, which will probably answer your question. For example, UE4 has a tool called "Composure" that allows you to achieve something similar. Here's a guide to get you fully set up.