I am trying to rebuild a surface, but find it difficult to set the proper UV values. Although the surface appears to have 3 points in the U direction and 5 points in the V direction, the “rebuild” command claims there to be 3 points in the U direction and 6 points in the V direction! Why is it 6 instead of 5? I’m also unsure about what the degree values signify, but for whatever reason here they are 1 and 2 respectively. I’d appreciate an explanation for what these UV values mean, and if my logic is flawed. Thank you
The Level 1 Training has a chapter explaining the concept of “degree” and how it relates to control points.
A surface or curve of a given “degree” has to have at least Degree+1 points.
In Nurbs, the degree refers to the highest exponent in the polynomial that defines each basis spline function / control function.
Mininum CV-Count is Degree + 1
The higher the degree the higher the internal continuity.
Best read some further and much more detailed infos:
Rhino, isoparms (isoparametric curves) are intrinsically related to knots within the context of Non-Uniform Rational B-Splines (NURBS) modeling.
Some of the.other link here should help.
Why are the number of isolarm lines important in this case?
Do not assume the number of interior isoparms/isocurves displayed is a simple function of the degree in each direction and the number of knots. It also depends on the Isocurve Density setting The effect of the Isocurve Density setting on the number of interior isocurves displayed is complicated and can be confusing.