Problem of distorsion using the displace modifier with an external displacement map Here my mesh, a simple tunnel with 2 modifiers :

1)  Subdivision surface 

2)  Displace Modifier



In particular the displace modifier is created with the default library of Blender, Clouds like the image above shows.

Now i have imported this seamless map below and i want to use it instead of Clouds. There it is:



This is my workflow:

1) I upgrade my definition with sub. surf. modifier, getting almost 200k vertices (this new displacement map need a mesh with more resolution in order to have a decent result).



2) I apply the sub modifier.

3) I select all my mesh in Edit Mode and I used Smart Uv Project for having a Uv Map with these stats below.



4) I open the displace modifier and insert the new displacement map. Here the stats I used:

 



The final results is pretty decent but there is a problem: there are 3 seams, that I underlined in red.







What could be the problem causing this distorsion? I tryed with many seamless texture and there are always these three lines.

Is there a method to fix it?

Here's the file, just in case



Thank you!!

EDIT: the problem could be created from seams of smart uv project. I tried with the unwrap and the results is this:





There is a way to fix it?
Just make one seam along the whole tube (not around). Simply unwrap it. You should get a square. If it matches the whole UV space it will be seamless.