GendL Application - non-rational-curve

Object: non-rational-curve (The :surf Package)

Mixins: curve

Author

Dave Cooper, Genworks International

Description

This object accepts a rational curve and approximates it with a non-rational curve.

Input Slots (required)

curve-in gdl curve object
Presumably this is a Rational curve (else this object will do nothing).

Input Slots (optional)

built-from [from curve] gdl curve
Specify this if you want this curve to be a clone of an existing curve. (note - this uses a shared underlying curve object, it does not make a copy)

color-decimal [from geometry-kernel-object-mixin] vector of three real numbers
The RGB color of this object as imported from an external format (e.g. IGES) or as specified in :display-controls. Defaults to the foreground color specified in `colors-default`. This message should not normally be overridden in user application code.

hidden? [from vanilla-mixin] boolean*
Indicates whether the object should effectively be a hidden-object even if specified in :objects. Default is nil.

iges-level [from geometry-kernel-object-mixin] integer
Synonym for the layer.

image-file [from base-object] pathname or string
Points to a pre-existing image file to be displayed instead of actual geometry for this object. Defaults to nil

layer [from geometry-kernel-object-mixin] integer
The primary IGES-compatible level (layer) on which this object resides. Defaults to the first of the levels. This slot can be overridden in user code to specify a new layer which will be written out when this object is exported with the IGES output-format.

levels [from geometry-kernel-object-mixin] list of integers
The IGES-compatible levels (layers) on which this object resides. GDL does not currently support writing out multiple levels (layers) through the IGES writer ; only the first of these will be output if the object is exported with the IGES output-format (please contact Genworks if you need all levels (layers) to be written out).

local-box [from base-object] list of two 3d points
The left front bottom and right rear top corners, in global coordinates, of the rectangular volume bounding this geometric object.

maintain-end-tangents? boolean
Determines whether to try to maintain tangents at the ends. Defaults to t.

non-rational-degree integer
Determines the degree of the non-rational curve. Defaults to 3.

obliqueness [from base-object] 3x3 orthonormal matrix of double-float numbers
This is synonymous with the `orientation`.

onclick-function [from base-object] lambda function of zero arguments, or nil
If non-nil, this function gets invoked when the user clicks the object in graphics front-ends which may or may not support this functionality (see viewport-html-div).

parameterization keyword symbol, one of :uniform, :chord-length, :centripetal, or :inherited
The default is :inherited.

root [from vanilla-mixin] gdl instance*
The root-level node in this object's ``tree'' (instance hierarchy).

safe-children [from vanilla-mixin] list of gdl instances*
All objects from the :objects specification, including elements of sequences as flat lists. Any children which throw errors come back as a plist with error information

strings-for-display [from vanilla-mixin] string or list of strings*
Determines how the name of objects of this type will be printed in most places. This defaults to the name-for-display (generally the part's name as specified in its parent), followed by an index number if the part is an element of a sequence.

tolerance number
The tolerance to use for non-rational approximation of a rational curve-in. Defaults to the curve-in's total length divided by the tolerance-divisor.

tolerance-divisor number
The amount by which to divide the total-length of the curve-in to compute the default tolerance. Default is 1000.

uv-curve [from curve] gdl curve object
The corresponding UV curve for the primary surface on which this curve lies, if any. If this is not a surface-curve, this will return an error.

visible-children [from vanilla-mixin] list of gdl instances*
Additional objects to display in Tatu tree. Typically this would be a subset of hidden-children. Defaults to NIL.

Input Slots (optional, defaulting)

center [from base-object] 3d point
Indicates in global coordinates where the center of the reference box of this object should be located.

display-controls [from base-object] plist
May contain keywords and values indicating display characteristics for this object. The following keywords are recognized currently: :color color keyword from the color-table parameter, or an HTML-style hexidecimal RGB string value, e.g. "#FFFFFF" for pure white. Defaults to :black. :line-thickness an integer, defaulting to 1, indicating relative line thickness for wireframe representations of this object. :dash-pattern (currently PDF/PNG/JPEG only). This is a list of two or three numbers which indicate the length, in pixels, of the dashes and blank spaces in a dashed line. The optional third number indicates how far into the line or curve to start the dash pattern.

height [from base-object] number
Z-axis dimension of the reference box. Defaults to zero.

length [from base-object] number
Y-axis dimension of the reference box. Defaults to zero.

orientation [from base-object] 3x3 matrix of double-float numbers
Indicates the absolute Rotation Matrix used to create the coordinate system of this object. This matrix is given in absolute terms (i.e. with respect to the root's orientation), and is generally created with the alignment function. It should be an orthonormal matrix, meaning each row is a vector with a magnitude of one (1.0).

width [from base-object] number
X-axis dimension of the reference box. Defaults to zero.

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