Using the Advanced conversion options

The following options are available when you select Advanced in the Fix drop-down list of the Convert to NURBS command. These settings enable you to have the maximum control on the surface continuity and precision.


 
Boundary continuity order
 		 Enables you to select the continuity order for the boundaries of the resulting surface: Position, Tangency or Curvature.
The continuity order along the boundaries is to be set as the first condition, as once it is set the internal continuity order for the selected surfaces (Continuity order, see below) is automatically set to the same degree.
 
Continuity order Enables you to select the continuity order for the internal areas of the resulting surface. Once the continuity order along the boundaries (Boundary continuity order, see above) has been set, the internal continuity will automatically be set to the same value (Position, Tangency or Curvature, according to the choice you've made).
If you select Maximum, the resulting entity will have the maximum continuity value at the internal knots, which is the entity degree minus 1 (high knot continuity, NURBS multiplicity = 1). For example if the entity degree is 7, continuity at internal knots will be 6. In general, the resulting entity will be much smoother.
 
Deg. U Enables you to define the actual degree for the resulting surface along the direction of parameter U.
 
Deg. V Enables you to define the actual degree for the resulting surface along the direction of parameter V.
 
Tolerance Enables you to control the tolerance settings.
  • High
    Default values (Position = 0.001, Tangency = 0.1 deg, Curvature = 0.05).
  • Medium
    Sets the tolerance values to the following: Position = 0.01, Tangency = 0.2 deg, Curvature = 0.1
  • Low
    Sets the tolerance values to the following: Position = 0.1, Tangency = 0.3 deg, Curvature = 0.15
Please note that if you modify the tolerance values described below, the Tolerance option is automatically set to Custom.
Position Enables you to set the tolerance value to be used in case of positional continuity, in millimeters or inches, depending on the current unit of measure. It is the difference between the real positional continuity and the one you can obtain.
 
Tangency Enables you to set the tolerance value to be used in case of tangency continuity, in degrees. It is the difference between the real tangency and the one you can obtain.
 
Curvature Enables you to set the tolerance value to be used in case of curvature continuity, as a percentage of the maximum curvature.
 
Internal Tolerance Ratio Enables you to set the ratio between the inner tolerance and the boundary tolerance. This can be very useful, as it enables you to balance the tolerance based on your own needs, either in the case you are more interested to the boundary conditions than to the inner conditions or vice versa.
 
Max. No. of Arcs Enables you to control the number of arcs, affecting the accuracy of the result:
  • When the check box is selected, you will be enabled to limit the number of arcs to the one you will enter.
    Please note that when this option is set, reaching a satisfying accuracy may take some time. Therefore, a progress bar is displayed to show the completion status of the computation.
  • When the box is not selected, the command will automatically generate as many arcs as needed in order to produce a surface within the specified tolerances.
Max. arcs U Enables you to define the maximum number of arcs for the resulting surface along the direction of parameter U.
 
Max. arcs V Enables you to define the maximum number of arcs for the resulting surface along the direction of parameter V.
 

Additional settings are available under More Options. See "Using additional conversion options (More Options)" for details.