Hi sosodef, for example here's what your same posted .obj file looks like when rendered in Cinema4D - note that when the vertex normals from the OBJ file are used by the renderer it helps to make very smooth looking surfaces in the rendered result:




One thing you could do in Blender to reduce the shading artifacts somewhat is to make a more finely diced up mesh, since the object is only gently curved in the long direction using just the "angle" parameter alone will not generate very many polygons in that direction, but you can use the "Divide larger than" setting to force the mesh to be more finely diced up and that will tend to reduce the kinds of shading artifacts that Blender will produce to be smaller in size at least. See here for a demo of using "Divide larger than":
http://moi3d.com/forum/index.php?webtag=MOI&msg=2833.5

But as you can see from the above quick C4D rendering, it's really better to use a rendering program that will read the smooth shading information that is stored in the OBJ file and use it when doing the rendering, it greatly helps to make the rendered result look the same as the original smooth NURBS surface did.

- Michael