Maya 2012 Tutorial
How to Control Nurbs Tessellation in Maya
Maya applies Tessellation to all Nurbs objects. It is used to break the object into a series of triangles. By adding more Tessellation, an object can become more rounded and smooth. Increasing the Tessellation too much slows your render times.
Add a Nurbs sphere primitive to the workspace by choosing Create > NURBS Primitives > Sphere.
Select the sphere and open the Attribute Editor, nurbsSphereShape tab.
Open the Tessellation section and click Display Render Tessellation. This displays how the object will be broken into triangles.
The object's current triangle count is displayed.
In the Simple Tessellation Options section you can set the Curvature Tolerance and Divisions Factor.
To activate the Advanced Tessellation section, first click the Enable Advanced Tessellation checkbox, then open the Advanced Tessellation section. Advanced Tessellation overrides the Simple Tessellation settings.
Within the Advanced Tessellation section there are two more sub-sections labeled Primary Tessellation Attributes and Secondary Tessellation Attributes.
Tessellation and Distance
Consider dropping the geometry detail and Tessellation settings for objects that are off in the distance to speed up your render times.
Setting Tessellation for Multiple Objects
You can set the Tessellation for several objects or all objects in the scene by selecting the objects and choosing Render > Set NURBS Tessellation (include options) from the Rendering menu set.