Problem with "Displacement"

[Erick]

I wanted to create a carpet.
To start things easy, I simply loaded the "square" primitive prop into an empty Poser scene (incl. the Ground Plane).
For the material set up, I started absolutely basic, by just using a diffuse material, an "RGB colour" as base colour and a noise map for the displacement, to see, how it'd look.
... and first things first, it didn't look good!
Because something is causing this big kind of a line at a perhaps random place, as soon as displacement is enabled.
By turning the camera a bit, the line appears at totally different place.
Did this happen to anyone, too?
What's the deal with it?

I have attached a few renders, to illustrate it:

[face_off]

You can try adjusting the rayepsilon, which might fix the problem. However it is more likely a problem where displacement is set too small relative to the size of the polygon it is place on - so subd the plane should also fix it.

Paul

[Erick]

Sometimes a fix can be so easy ... sub'ding the square a few times indeed did the job.
Thanks for the help!