I am quite confused on how I can make a part with reflectance show a building or a user standing infront of the block reflected on it.
Whenever I set reflectance to full, I just see the skybox being reflected or in other words something that just makes the whole map transparent and allows you to see the skybox.
There are free models for reflecting players, to reflect the surroundings you just need to copy, paste and flip it then slap either a transparent glass part or plastic part depending on lighting, you will have to play around with it but ive seen it done to varying degrees of success
You could try making a avatar clone script to replicate player movements and appearance for that reflective surface and then copy paste the terrain/parts and place it behind the reflective surface to give it the illusion that is actually a full on reflection… (Its not for every use case, but its the least demanding) Or you could maybe try waiting until Roblox implements some kind of ray traced reflection system (Not Screen Space, VERY DEMANDING, Should work for everything but not for every player.)