Strange displacement behaviour

Rhino Rhino for Windows
1

Hello
I have trouble getting my displacements right in Rhino 7
The following are supposed to be similar

The bottom piece, which looks properly displaced, is a square tube. Displacement is applied not through the material, but through the displacement tab.
The middle piece is a cylinder tube, with the same displacement effect based on the same texture. And i also copied the UV mapping from the first piece. So in my understanding, it should look quite similar (it doesn’t)
The third piece is a cylinder tube, and I applied the same displacement texture, as a map in a PBR material. As you can see, almost no displacement appears. I suspect a mapping issue since there seems to be a little displacement on the opposite ends of the tube, but nothing on the tube itself. However besides the displacement, my texture looks right;

Capture d’écran 2022-10-12 154239
Capture d’écran 2022-10-12 1542391612×1108 317 KB

Any clue?

thanks!!

2

It would be better to have the file and textures, but my guess is that the render meshes are not fine enough - the Rhino displacement tool can refine the rendeer mesh so that there is enough resolution to show something, but I do not think the material based displacement can do that.

-Pascal