b-spline-surface

GDL Instance. In an element of a sequence, this is the container object which holds all elements.

List of Symbols. Lists all the superclasses of the type of this object.

Number. Returns the area of the surface.

:&key ((desired-accuracy 0.000001) "Number. Desired accuracy of result. Should not be smaller than 0.00000001 (10e-08).")

3D Vector. Returns the vector pointing in the positive direction of the specified axis of this object's reference box. :arguments (axis "Keyword. One of the standard axis keywords: :lateral, :longitudinal, :vertical.")

List of lists 3D points, List of lists numbers, List of numbers, List of numbers, Integer, and Integer. Returns six values which are the control points, the weights, the u-knots, the v-knots, the u-degree, and the v-degree of the surface.

GDL object of type Box. A box representing the bounding-box.

List of two 3D points. The left front bottom and right rear top corners, in global coordinates, of the rectangular volume bounding the tree of geometric objects rooted at this object.

GDL Brep object. This is the brep representation of this 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.

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)

3D Point. Indicates in global coordinates where the center of the reference box of this object should be located.

List of GDL Instances. All objects from the :objects specification, including elements of sequences as flat lists.

List of GDL Instances. All objects from the :objects specification, including elements of sequences as flat lists.

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.

List of lists of 3D Points. The control net.

Surface point. Returns the first point of intersection between this surface and the curve given as an argument.

:arguments (curve "GDL Curve object. The curve to intersect with this surface.") :&key ((3d-tolerance 3d-tolerance-default) "Number. The tolerance to use for intersecting.")

List of Surface points. Returns the point(s) of intersection between this surface and the curve given as an argument.

:arguments (curve "GDL Curve object. The curve to intersect with this surface.") :&key ((3d-tolerance 3d-tolerance-default) "Number. The tolerance to use for intersecting.")

List of Symbols. Lists the direct superclasses of the type of this 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.

Plist. Returns the :documentation plist which has been specified the specific part type of this instance.

Plist. Returns plist containing :min and :max indicating min and max UV points for parameter space for this surface.

Surface point. Returns the given 3D point dropped normally to this surface, as close as possible to the given 3D point.

:arguments (point "3D Point. The point to be dropped.") :&key ((3d-tolerance 3d-tolerance-default) "The tolerance used for dropping.")

List of Surface points. Returns the given 3D point dropped normally to this surface.

:arguments (point "3D Point. The point to be dropped.") :&key ((3d-tolerance 3d-tolerance-default) "The tolerance used for dropping.")

3D Point. Returns the center of the requested edge of this object's reference box. :arguments (direction-1 "Keyword. One of the standard direction keywords: :right, :left, :rear, :front, :top, :bottom." direction-2 "Keyword. A standard direction keyword orthogonal to direction-1.")

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.

3D Point. Returns the center of the requested face (the requested face with respect to the wrt argument if present, or self if wrt is nil) of this object's reference box. :arguments (direction "Keyword. One of the standard direction keywords: :right, :left, :rear, :front, :top, :bottom.")

(wrt "GDL object instance. Reference object for axes")

3D Vector. Returns the vector pointing from this object's reference box center to its requested face-center. :arguments (direction "Keyword. One of the standard direction keywords: :right, :left, :rear, :front, :top, :bottom.")

List of four 3D points. Returns the vertices of the indicated face.

:arguments (direction "Direction keyword, e.g. :top, :bottom etc. Indicates for which face to return the vertices.")

Boolean. For elements of sequences, T iff there is no previous element.

GDL Instance. Using this instance as the root, follow the reference chain represented by the given path. :arguments (path "List of Symbols or Pairs of Symbol and Integer")

3D-point. This function returns the point given in global coordinates, into relative local coordinates, based on the orientation and center of the object to which the global-to-local message is sent.

:arguments (point "3D-point. The point to be converted to local coordinates")

:examples Please see the examples area.

Number. Z-axis dimension of the reference box. Defaults to zero.

List of GDL Instances. All objects from the :hidden-objects specification, including elements of sequences as flat lists.

Boolean. Indicates whether the object should effectively be a hidden-object even if specified in :objects. Default is nil.

Integer. Synonym for the layer.

Pathname or string. Points to a pre-existing image file to be displayed instead of actual geometry for this object. Defaults to nil

Boolean. Returns non-nil if the given point is in halfspace defined by the plane given a point and direction.

:arguments (point "3D point. a point in the plane" direction "3D vector. The normal of the plane")

Integer. Sequential index number for elements of a sequence, NIL for singular objects.

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.

Boolean. For elements of sequences, T iff there is no next element.

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.

Boolean. T if this object has no children, NIL otherwise.

List of GDL Objects. A Collection of the leaf nodes of the given object.

List of GDL Objects. A Collection of the leaf nodes of the given object.

Number. Y-axis dimension of the reference box. Defaults to zero.

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).

List of 3D points. Returns the points of intersection between given line and the reference box of this object.

:arguments (p-line "3D point. A point in the line" u-line "3D vector. The direction vector of the line")

GDL object of type Box. A box representing the local-box.

Returns a bbox object, answering xmin, ymin, zmin, xmax, ymax, and zmax, for a box containing the convex hull (i.e. the control points) of this surface and oriented according to the given center and orientation.

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.

3D Point. The center of this object, from the perspective of the parent. Starting from the parent's center and using the parent's orientation, this is the relative center of this object.

3D Point. The center of this object, from the perspective of the parent. Starting from the parent's center and using the parent's orientation, this is the relative center of this object.

3x3 Matrix of Double-Float Numbers. Indicates the local Rotation Matrix used to create the coordinate system of this object. This is the "local" orientation with respect to the parent. Multiplying the parent's orientation with this matrix will always result in the absolute orientation for this part.

:note An orientation of NIL indicates the 3x3 identity matrix.

3D-point. This function returns the point given in relative local coordinates, converted into global coordinates, based on the orientation and center of the object to which the local-to-global message is sent.

:arguments (point "3D-point. The local point to be converted to global coordinates")

:examples Please see the examples area.

Plist. The returned plist contains information about the maximum distance from this surface to the curve given as the argument.

:arguments (curve "GDL Curve object")

Plist. The returned plist contains information about the maximum distance from this surface to the surface given as the argument.

:arguments (surface "GDL Surface object")

String. This is synonymous with slot-documentation

List of Keyword Symbols. Returns the messages (slots, objects, and functions) of this object, according to the filtering criteria as specified by the arguments. :&key ((category :all) "Keyword. Either :all or the individual category of messages to be returned. This can be one of:

• :computed-slots

• :settable-computed-slots

• :required-input-slots

• :optional-input-slots

• :defaulted-input-slots

• :query-slots

• :functions

• :objects

• :quantified-objects

• :hidden-objects

• :quantified-hidden-objects

" (message-type :global) "Keyword Symbol, :local or :global. Indicates whether to return messages only from the local specific part type, or from all superclasses (mixins) as well." (return-category? nil) "Boolean. Indicates whether or not the category of each message should be returned before each message in the returned list." (base-part-type nil) "Symbol naming a GDL Part Type. Indicates a "base" part from which no messages should be returned, nor should messages be returned from superclasses (mixins) of this base part. If NIL (the default), messages are considered from all superclasses." (sort-order :unsorted) "Keyword Symbol. One of: :unsorted, :by-category, or :by-name." (filter :normal) "Function Object of two arguments or :normal. If a function object, applies this function to each returned category and message keyword, and filters out all pairs for which the function returns NIL. If :normal (the default), then no filtering is done.")

Plist. The returned plist contains information about the minimum distance from this surface to the curve given as the argument.

:arguments (curve "GDL Curve object")

Plist. The returned plist contains information about the minimum distance from this surface to the surface given as the argument.

:arguments (surface "GDL Surface object")

List of Symbols. Returns the names of the immediate superclasses of this object.

:&key ((local? t) "Boolean. Indicates whether to give only direct mixins or all mixins from the entire inheritance hierarchy.")

Keyword symbol. The part's simple name, derived from its object specification in the parent or from the type name if this is the root instance.

GDL Instance. For elements of sequences, returns the next part in the sequence.

3D Vector. The surface normal vector at the given u and v values. Three other values are also returned: The 3D point, the U tangent, and the V tangent at the given parameter value.

3x3 Orthonormal Matrix of Double-Float Numbers. This is synonymous with the orientation.

3D Point. Returns the surface point at the given parameters offset along the surface normal at that point by the given distance. :arguments (u "Number. The U parameter for the surface point." v "Number. The V parameter for the surface point." distance "Number. The distance for offsetting.")

Boolean. Returns non-nil if the given UV (2D) point lies within the parameter space of this surface. Currently this function works only on the basis surface ; it does not observe trimming island or holes.

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).

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).

GDL Instance. The parent of this object, or NIL if this is the root object.

3D Point. The point on the surface corresponding to the given u and v parameter values.

GDL Instance. For elements of sequences, returns the previous part in the sequence.

Surface point. Returns the first result of the given point projected along the given vector intersected with the surface.

:arguments (point "3D Point. The point to be projected." vector "3D Vector. The vector along which to project.")

List of Surface points. Returns the given point projected along the given vector intersected with the surface.

:arguments (point "3D Point. The point to be projected." vector "3D Vector. The vector along which to project.")

Number. Returns the Gaussian curvature on the surface at the given parameter values. Three additional values are returned, which are the Normal Curvature at the point, the first Fundamental Principle Curvature, and the second Fundamental Principle Curvature.

:note This function might be updated to provide a clearer idea of actual radius of curvature; at the time of this writing it is not clear what the relationship is between the four returned values and actual radius of curvature.

:arguments (u "Number. The U parameter for the surface point." v "Number. The V parameter for the surface point.")

Boolean. Returns non-nil iff this surface is rational, i.e. all weights are not 1.

Void. Restores all settable-slots in this instance to their default values.

Multiple Values: Total root-paths affected and total slots affected. Reverts any "remembered" bashed slots, starting from the root, to their default values. Note that any call to set-slot! or set-slots! or any use of web form-controls will result in "remembered values". Note that there is a :remember? keyword argument to set-slot! which defaults to t but if you specify it as nil, you can bash values without having them "remembered" and such slots would not be affected by this function.

NIL. Restores the value of the given slot to its default, thus "undoing" any forcibly set value in the slot. Any dependent slots in the tree will respond accordingly when they are next demanded. Note that the slot must be specified as a keyword symbol (i.e. prepended with a colon (":")), otherwise it will be evaluated as a variable according to normal Lisp functional evaluation rules. :arguments (slot "Keyword Symbol") :key (force? "Boolean. Specify as t if you want to force non-settable slots to recompute (e.g. reading from databases or external files). Defaults to nil.")

nil. Restores the value of the given slots to their defaults, thus "undoing" any forcibly set values in the slots. Any dependent slots in the tree will respond accordingly when they are next demanded. Note that the slots must be specified as keyword symbols (i.e. prepended with colons (":")), otherwise they will be evaluated as variables according to normal Lisp functional evaluation rules.

:arguments (slots "List of Keyword Symbols")

:&key ((force? force-restore-slot-default?) "Boolean. Indicates whether the slot values should be unbound, regardless of whether it had actually been bashed previously.")

Void. Restores all settable-slots in this instance, and recursively in all descendant instances, to their default values.

GDL Instance. The root-level node in this object's "tree" (instance hierarchy).

List of Symbols or of Pairs of Symbol and Integer. Indicates the path through the instance hierarchy from the root to this object. Can be used in conjunction with the follow-root-path GDL function to return the actual instance.

List of Symbols or of Pairs of Symbol and Integer. Indicates the path through the instance hierarchy from the local root to this object. Can be used in conjunction with the follow-root-path GDL function to return the actual instance.

Boolean. T iff this part has NIL as its parent and therefore is the root node.

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

List of GDL Instances. All objects from the :hidden-objects specification, including elements of sequences as flat lists. Any children which throw errors come back as a plist with error information

NIL. Forcibly sets the value of the given slot to the given value. The slot must be defined as :settable for this to work properly. Any dependent slots in the tree will respond accordingly when they are next demanded. Note that the slot must be specified as a keyword symbol (i.e. prepended with a colon (":")), otherwise it will be evaluated as a variable according to normal Lisp functional evaluation rules.

Note also that this must not be called (either directly or indirectly) from within the body of a Gendl computed-slot. The caching and dependency tracking mechanism in Gendl will not work properly if this is called from the body of a computed-slot, and furthermore a runtime error will be generated.

:arguments (slot "Keyword Symbol" value "Lisp Object. (e.g. Number, String, List, etc.)")

:&key ((remember? t) "Boolean. Determines whether to save in current version-tree." (warn-on-non-toplevel? t) "Boolean. Determines whether to warn if this is called from the body of a cached slot." )

NIL. Forcibly sets the value of the given slots to the given values. The slots must be defined as :settable for this to work properly. Any dependent slots in the tree will respond accordingly when they are next demanded. Note that the slots must be specified as a keyword symbols (i.e. prepended with a colon (":")), otherwise they will be evaluated as variables according to normal Lisp functional evaluation rules. :arguments (slots-and-values "Plist. Contains alternating slots and values to which they are to be set." warn-on-non-toplevel? "Boolean. Indicates whether a warning should be issued for calling from inside the body of a cached slot. Default is t.")

Boolean. Indicates whether brep representation should undergo a sew-and-orient operation. Defaults to nil.

Plist of Symbols and Strings. Returns the part types and slot documentation which has been specified for the given slot, from most specific to least specific in the CLOS inheritance order. Note that the slot must be specified as a keyword symbol (i.e. prepended with a colon (":")), otherwise it will be evaluated as a variable according to normal Lisp functional evaluation rules. :arguments (slot "Keyword Symbol. Names the slot for which documentation is being requested.")

Body of GDL code, in list form.

:arguments (slot "Keyword Symbol. Names the slot for which documentation is being requested.")

Keyword symbol. Describes the current status of the requested slot:

• :unbound: it has never been demanded.

• :invalidated: it was demanded at some point, but something it depends on has been modified since; it is currently unbound and will be re-evaluated on next demand.

• :evaluated: it has been demanded and it is currently bound to the default value based on the code.

• :set: (for :settable slots only, which includes all required :input-slots) it has been modified and is currently bound to the value to which it was explicitly set.

• :toplevel: (for root-level object only) its value was passed into the root-level object as a toplevel input at the time of object instantiation.

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.

GDL surface object. This surface object swaps the role of u and v- directional parameters, i.e. old-surface(u,v) = new-surface(v,u).

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*)

Void. Sets giving slot to its boolean opposite. &args (slot "Keyword symbol. Name of the slot as a keyword symbol.")

Number. Approximation tolerance for display purposes.

Symbol. The GDL Type of this object.

Integer. Degree of surface in U direction. Defaults to 3.

Sequence of curve objects. The isoparametric curves in the U direction.

List of Numbers. Knots in U direction. Default is NIL, which indicates a uniform knot vector in U direction.

Number. Returns maximum U component of the surface parameter space.

Number. Returns minimum U component of the surface parameter space.

Void. Uncaches all cached data in slots and objects throughout the instance tree from this node, forcing all code to run again the next time values are demanded. This is useful for updating an existing model or part of an existing model after making changes and recompiling/reloading the code of the underlying definitions. Any set (modified) slot values will, however, be preserved by the update.

Integer. Degree of surface in V direction. Defaults to 3.

Sequence of curve objects. The isoparametric curves in the V direction.

List of Numbers. Knots in V direction. Default is NIL, which indicates a uniform knot vector in V direction.

Number. Returns maximum V component of the surface parameter space.

Number. Returns minimum V component of the surface parameter space.

3D Point. Returns the center of the requested vertex (corner) of this object's reference box. :arguments (direction-1 "Keyword. One of the standard direction keywords: :right, :left, :rear, :front, :top, :bottom." direction-2 "Keyword. A standard direction keyword orthogonal to direction-1." direction-3 "Keyword. A standard direction keyword orthogonal to direction-1 and direction-2.")

List of GDL Instances. Additional objects to display in Tatu tree. Typically this would be a subset of hidden-children. Defaults to NIL.

List of lists of numbers. A weight to match each control point. Should be congruent with control-points (i.e. same number of rows and columns). Default is a value of 1.0 for each weight, resulting in a nonrational surface.

Number. X-axis dimension of the reference box. Defaults to zero.

Void. Writes a file containing the toplevel inputs and modified settable-slots starting from the root of the current instance. Typically this file can be read back into the system using the read-snapshot function.

:&key ((filename "/tmp/snap.gdl") "String or pathname. The target file to be written." (root-paths-to-ignore nil) "List of root-paths or nil. Any objects with matching root-path will be ignored for the snapshot write." )