When you use nurbs surface, from time to time, you might want to how its tessellation.
You can simply turn on Display Render Tessellation option under Tessellation section in the attribute editor to see it. But that's for Maya software render and doesn't necessarily match Mental ray's tessellation. To be able to mental ray's tessellation, you need to use Mental ray's contour rendering feature.
Here I have two simple nurbs sphere. For comparison, I turned on Display Render Tessellation option
for the sphere on the right side. And I also turned on Enable Advanced Tessellation. This is to explicitly assign the number of tessellation for each span for the sphere.
Next, I will create a new surface shader and assign it to the sphere on the right. This shader is for contour line. After the shader assignment, select the shader's shading group node and open the attribute editor.
