NURBS curves and surfaces are curved in a continuous manner, while computer display better deals with straight lines and flat polygons. For this reason, NURBS curves and surfaces are tessellated into polylines and polygons at redrawing time.
The representation quality of the object improves as the number of subdivisions of a surface grows. The number of subdivisions generally depends on the number of control points defining a surface.
The Customize View Detail panel allows you to define your preferred detail setting.
In particular, the Wireframe, Shaded/Textured sections of the panel give you control over surface detail, while the Lines section is used to adjust curves detail.
Three different methods can be chosen from the Method pull-down menu.
They are:
Fixed method
The number of control points does not affect the number of subdivision,
which is fixed and corresponds to the parameter Resolution.
Linear method
The number of subdivisions is linearly proportional to the number of control
points according to the formula: subdivision = resolution * control points.
Log10 method
The number of subdivisions is linearly proportional to the number of control
points according to the formula: subdivision = resolution * log10 (control
points)
Compared to Linear, the Log10 method allows you to contain the number of subdivisions in case of surfaces with numerous control points.
After choosing the method, for each section of the Customize View Detail, you can set other visualization parameters.
Resolution determines the level of detail. The effect of this setting changes depending on the method you choose. See the above discussion and related charts.
You can limit the number of subdivisions in a range comprised between a minimum and a maximum value. In particular, Minimum determines the minimum number while Maximum determines the maximum number of subdivisions allowed, even though a high level of detail has been set in the resolution field.
A fourth method, Adaptive, is available only in the Shaded/Textured section. It allows you to set a tolerance value which forces the tessellation to subdivide regions of the surface with high curvature, until the distance between the surface and the approximating tessellation is less than the tolerance specified. The Tolerance is intended to be a fraction of the diagonal of the surface bounding box.
Press OK to confirm all changes and close the panel, Apply to apply changes without closing the panel, Cancel to cancel any changes.