Unable to add displacement texture

I was trying to add a granite texture to the polysurface but it is not showing, I tried to turn the object to a mesh but it is still the same, what could have gone wrong?

Hi Hiu Lam -

A picture might not be telling us enough and it’d be better if you post a 3dm file.
That said, are the following plug-ins both enabled and loaded?
image

-wim