GendL Application - spherical-surface

Object: spherical-surface (The :surf Package)

Description

A surface representation of the sphere. Takes the same inputs as native GDL sphere. Partial spheres are not yet implmented. Note that some VRML browsers, e.g. Cortona v. 4.2, show some spurious artifacts with NURBS created as spherical surfaces. BS Contact does not appear to have this problem.

Input Slots (required)

radius [from sphere] number
Distance from center to any point on the sphere.

Input Slots (optional)

brep-tolerance [from surface] number
Overall tolerance for the internal brep representation of this surface. Defaults to nil. Note that a value of nil indicates for SMLib a value of 1.0e-05 of the longest diagonal length of the brep.

built-from [from surface] gdl surface
Specify this if you want this surface to be a clone of an existing surface (note - this uses a shared underlying surface 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.

end-angle [from arcoid-mixin] angle in radians
End angle of the arc. Defaults to twice pi.

end-caps-on-brep? [from surface] boolean
Indicates whether to attempt automatic endcaps on conversion of this surface to a brep. Note that this might change in future to a keyword value for :min, :max, or :both to provide more control.

end-horizontal-arc [from sphere] angle in radians
Ending horizontal angle for a partial sphere. Default is twice pi.

end-vertical-arc [from sphere] angle in radians
Ending vertical angle for a partial sphere. Default is pi/2.

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

inner-radius [from sphere] number
Radius of inner hollow for a hollow sphere. Default is NIL, for a non-hollow sphere.

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).

number-of-horizontal-sections [from sphere] number
How many lines of latitude to show on the sphere in some renderings. Default value is 4.

number-of-vertical-sections [from sphere] number
How many lines of longitude to show on the sphere in some renderings. Default value is 4.

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).

rational? [from surface] boolean
Returns non-nil iff this surface is rational, i.e. all weights are not 1.

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

sew-and-orient-brep? [from surface] boolean
Indicates whether brep representation should undergo a sew-and-orient operation. Defaults to nil.

start-angle [from arcoid-mixin] angle in radians
Start angle of the arc. Defaults to zero.

start-horizontal-arc [from sphere] angle in radians
Starting horizontal angle for a partial sphere. Default is 0.

start-vertical-arc [from sphere] angle in radians
Starting vertical angle for a partial sphere. Default is -pi/2.

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.

tessellation-parameters [from surface] plist of keyword symbols and numbers
This controls tessellation for the brep of this surface. The keys are as follows: `:min-number-of-segments` `:max-3d-edge-factor` `:min-parametric-ratio` `:max-chord-height` `:max-angle-degrees` `:min-3d-edge` `:min-edge-ratio-uv` `:max-aspect-ratio` and the defaults come from the following parameters: (list :min-number-of-segments tess-min-number-of-segments :max-3d-edge-factor tess-max-3d-edge-factor :min-parametric-ratio tess-min-parametric-ratio :max-chord-height tess-max-chord-height :max-angle-degrees tess-max-angle-degrees :min-3d-edge tess-min-3d-edge :min-edge-ratio-uv tess-min-edge-ratio-uv :max-aspect-ratio tess-max-aspect-ratio)

tolerance [from surface] number
Approximation tolerance for display purposes.

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.

isos [from surface] plist with keys :n-u and :n-v
The number of isoparametric curves to be displayed in each direction. This value comes from the value of :isos on the display-controls if that exists, and defaults to isos-default otherwise.

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).

Examples

                  
 (in-package :surf)

 (define-object test-spherical-surface (spherical-surface)
   :computed-slots ((display-controls (list :color :sky-summer))
                    (radius 10)))

 (generate-sample-drawing :objects (make-object 'test-spherical-surface)
                          :projection-direction :trimetric)

Package Documentation