Y Position
The floor is set to a Y value of (-1), but you can adjust it as needed.
NOTE:
For SkyBox, this value defaults to zero (0).
ELABORATIONS
Mirror
This creates a basic mirror reflection on the floor.
Shadow Contact
This generates a dark shadowy halo on the floor, without using lights.
Fog
The fog engulfs the scene and creates a sense of visual depth, thus contributing to a more dramatic scene effect.