Compositing Film With Reflective/Refractive 3D Objects

Hey,

I’m trying to combine some cgi elements (not sure what yet - probably crystals and glowing things) with a film, and I’m stuck with how to combine them without it looking overly fake.
The film will be filmed with a tripod with a single person in, and they won’t be moving that much.

I’ve found ways to do it with diffuse objects, like this:

But I can’t seem to find any way to do it with objects where the object has to reflect/refract the film.

I’ve thought about maybe green screening it then making all the background in Blender, but I still have the issue of the person not being reflected.

I know that this must be possible (they do it in movies!) but I’m not sure how/where to start with this, or whether it’s even possible with Blender?

if your enviroment is static(not moving) then you just take a 360degree panorama of it and use that as enviroment map in blender.
this will work for most scenes where isnt much movement in the objects or camera
for all other shots you need to rebuild the enviroment in blender and project (photo) textures on it. best would be to use some photogrametry software, which semi automatically builds the 3d scene from different photos and sticks the right textures to it.

if you then have a HDR of the scene/enviroment you also have the nearly perfect lighting on your objects.

if you need to see other sides of the objects in the reflection as the camera sees, you would need a second or more cameras to film the scene from the other angles