Any idea how to acheave infinite floor look?

http://greyscalegorilla.com/tutorials/how-to-make-the-infinite-floor-look-in-cinema-4d/
^^ That is the look im talking about, i've tried searching on google but i couldn't find anything, so that's why im here asking for help.
So yea how to get that circular gradient background with infinite floor in Unity?
Thanks in advance.

 

A mesh that curves up? A skybox gradient?

 

Maybe an inverted chamfer box could do.