So, I've been researching Reflection Probes in StudioNeoV2. I really think they're important for creating good-looking scenes.
Since I haven't seen this elsewhere, here's a very introductory tutorial:
To enable them, in Studio, use the Graphics plugin. First, put on some sort of Environment Skybox, giving you a background to work from. Then, go to Settings and, under Rendering, check Realtime Reflection Probes. If your hardware is limited you can put on a Pulse, which means reflection updates just once every x seconds. Or you can just check Realtime Reflection Probes and uncheck Pulse, which is more draining but means it updates constantly. Important if you want to reflect moving objects.
Then, go to Lighting. Here you will see Reflection Probes, which are the probes currently placed in your scene. If you've opened up a fresh scene there will probably be a Default Reflection Probe here already. (If there isn't, NYAACHO has Reflection Probe items you can place manually; place one at coordinates 0, 0, 0. You will want several probes if you have a larger scene, but start with one.) Its Importance should be at 100, Intensity at 1.0, Blend Distance at 1.0, Box Size: 100, 100, 100. These settings are important to adjust if you have multiple probes, since they decide priority over what should be reflected where, but leave them as is if you only have one probe in your scene. I check HDR and put Resolution to 2048.
Now, to see what the probe does, place a Sphere or some other basic white shape in your scene, on coordinates like 0, 10, 0. Then, go into its Material Editor. I tend to switch shader to Hanmen/Item Cutoff. Then, first set its DetailMetallicScale (which should start at 0), set it to -1. This is gives the Sphere a diffuse reflective look. If you have a skybox that is, f.ex. green, the Sphere will now be green. If you switch skybox you can see the Sphere change color accordingly. But still, it doesn't give much of a reflection? Well, to make it mirror its surroundings, under Material Editor set its Glossiness to 1.
View attachment 2186675
Now the Sphere is now a perfect mirror, even reflecting moving objects. Try placing other items around it and giving them an animation.
Note that the Reflection Probe is like a 360* camera of its surroundings, and the picture it takes is plastered onto every reflective object in its Box area, including the Sphere. So, if you were to place the Sphere on top of the Reflection Probe (probably on 0, 0, 0 coordinates), it should become pitch black, since it blocks the Reflection Probe from taking its pictures. It also blocks every other object inside the Box area from receiving/throwing reflections (including the Sphere). If you need an object (e.g. the Sphere) to be in that spot you should set its shader to Alpha rather than Cutoff.
So, you can now create mirrors, but, you ask - other than that - what is the point of all this? Well, in real life things are reflective, to a greater and lesser extent, even when they're not full mirrors. When clothes, skin, hair, walls, floors, etc. reflect things around them more accurately, the scene looks a lot more realistic. And, with control over Reflection Probe(s) in your scene, you have more control over this, especially when combined with editing the glossiness and reflectiveness of surfaces using Material Editor or Character Creator.
If you want more info you can look up Reflection Probes in Unity, since StudioNeoV2 with Graphics plugin works similarly.