Strange lines appearing when render Anisotropic BSDF I'm trying to render a steel plate with the Anistoropic BSDF. I would like to have curved reflections as it happens in pans or pots (for cooking). Instead, when I render, I get this strange straight lines appearing on the plate surface, and I cannot get rid of them. As a source light I'm using two planes with emmision. Here are images of the case (with the plate nodes) and of the rendered image. I don't know it this can help, but it was created with FreeCAD. May be it can be related with the problem. 

Here is the link to the blender file



Thanks all for you help.

David
Here is the final fixed result:



Shading

You need to click on the Tangent menu in the material settings and select a Tangent node. Make sure Radial is selected it its settings. Play around with the Axes: to figure out which one to use.



Gandalf3's image from here.

Modeling

Your mesh is covered in triangles (not good). From the .blend file that I downloaded, this was my process:


A twice to select everything.
Alt + J converts many tris to quads.
Ctrl + Tab, then 3 to enter Face Select Mode.
Alt +  RMB while hovering over one of the edges around the outside rim to select this face loop:





Ctrl + I to Invert Selection.
X > Faces to open the Delete menu and delete Faces.
Ctrl + Tab, then 1 to enter Vertex Select Mode.
Alt +  RMB while hovering over one of the edges in the topmost edge loop to select this edge loop:





F to create an N-Gon face.
Ctrl + I to Invert Selection.
F to create an N-Gon face.
Tab out of Edit Mode.


Here is the fixed .blend file:



P.S.

This is not included in the .blend file, but if you want less spotty anisotropy, you should use these settings in the Properties panel > Render tab.



They produce this result: