Basis surface node

Provides operations for moving knots within the parametric space of a NURBS curve or surface.

This op provides a set of operations applicable to the parametric space of spline curves and surfaces. The parametric space, also known as the “domain” of a NURBS or Bezier primitive, is defined by one basis in the U direction and, if the primitive is a surface, another basis in the V direction. The size of the domain is given by the values of the knots that make up the basis.

The Basis op contains both ratio-preserving and non ratio-preserving operations.

If the basis reparameterization does not change the distance ratios between knots, the shape of a NURBS primitive is not affected. If the ratios are not preserved; however, a NURBS primitive will change shape in the area influenced by the modified knots. Additionally, if the primitive is a NURBS or Bezier surface, any profiles it may contain will be affected as well.

Parameters

Group	Subset of spline primitives to operate on.
Edit the U Basis	Enables and disables transformations of the U basis below.
Edit the V Basis	Enables and disables transformations of the V basis below.

Parameterization

Parameterization method.

Unchanged	Does not change the U basis.
Uniform	Distributes all knots evenly.
Chord Length	Computes knot ratios based on primitive chord length.
Centripetal	Similar to chord length, useful for sharp turns.
Manual:Single	Edit knots of first spline primitive individually.
Manual:Propagated	Same as above but copy knots to all other primitives.
Knotslide	Shift clusters of knots within the basis.
Approximate Arc Length	Computes knot ratio based on an approximate primitive arc length.

Knot Sequence

Editable field of knots in ascending order.

Read Basis

Reads knots of first primitive into the field above.

Range

Area of the unit U domain to be shifted.

Bias

Amount and direction of shift in knotslide.

Map

Concatenate	Indicates whether bases should be concatenated.
Origin	New origin of the U basis.
Length	New length of the U basis.
Scale	Multiplier applied to basis at its origin.

Order

Raise To

Enables and disables raising of the basis order.

Usages in other examples

Example name	Example for
BridgeCurvesandPrims	Bridge surface node	Load \| Launch