Creo Reverse Engineering (Restyle) > Creating Polynomial Surfaces in Restyle > About Defining the Mathematical Properties of Surfaces
  
About Defining the Mathematical Properties of Surfaces
For creating polynomial surfaces using four points, the end points of a cross, and from a selection box, you can define the mathematical properties of a surface when you create some types of surfaces. You can also set these properties on the Modify Shape tab or in the Properties dialog box.
You can select the following surface types from the Type list:
Spline—Controls only the number of segments. Increase the number of points to achieve a better fit and projection and better matching for position or tangency constraints. Use this surface type for organic shapes and constrained surfaces, for example, fillets.
Bezier—Controls only the degree of the polynomial. Increase the degree for a better fit. This surface type is not suitable for constrained surfaces. Use this surface type for large and smooth surfaces. Using this surface type can give you the best surface quality.
B-spline—Controls the degree of the polynomial and the number of segments. Specifying a lower degree and more segments results in a surface similar to a Spline surface. Specifying a higher degree and fewer segments results in a surface similar to a Bezier surface.
 
The Bezier and B-spline surfaces can have a maximum value of 15 for the U and V degrees.
A B-spline surface with two segments (params) in both U and V directions is a Bezier surface.
You can modify the surface properties of any analytical surface that does not have multiple components. When the properties are modified, this surface becomes a polynomial surface.
After creating a surface, you can change its definition by clicking Mathematical Properties and changing the surface properties in the Properties dialog box. Changing surface properties produces the following results:
As the number of segments or degree increases, the surface becomes more flexible and easily manipulated. Surfaces with a high number of segments closely follow the facet data and can be fitted to the facet data with better accuracy.
Fewer segments or a low degree makes a more rigid surface. This type of surface appears smoother and more aesthetic.