TYPE: SOP
TITLE: Basis SOP

The Basis operation manipulates the parametric space (the basis) of NURBS and
Bezier primitives. If the reparameterization does not change the ratios between
knots, the primitive's shape is not affected. Otherwise, NURBS primitives will
change in the area affected by the modified knots and curves on surface will be
distorted.

Parameters:
    Group          - Subset of spline primitives to operate on.

    U              - Enables and disables transformations of the U basis below.
    V              - Enables and disables transformations of the V basis below.
Parameterize
    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    /urange1
                                                                       /urange2
    Bias                  - Amount and direction of shift in knotslide /ubias
Map
    Concatenate       - Indicates whether bases should be concatenated
    Origin            - New origin of the U basis                  /uorigin
    Length            - New length of the U basis                  /ulength
    Scale             - Multiplier applied to basis at its origin  /uscale

Order
    Raise To          - Enables and disables raising of the basis order
    Order             - The new basis order                        /orderu

Parameterize
    Parameterization  - Parameterization method
        Unchanged         - Does not change the V 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
    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 V domain to be shifted    /vrange1
                                                                       /vrange2
    Bias                  - Amount and direction of shift in knotslide /vbias
Map
    Concatenate       - Indicates whether bases should be concatenated
    Origin            - New origin of the V basis                  /vorigin
    Length            - New length of the V basis                  /vlength
    Scale             - Multiplier applied to basis at its origin  /vscale
Order
    Raise To          - Enables and disables raising of the basis order
    Order             - The new basis order                        /orderv
