0 (default) : Polyline
1 : From AP242E2 : minimal presentation (see placeholder) , this mode is active only when writing FDT with Semantics (inMode = 1 or 2)
(in previous versions of STEP, or FDT as Graphics only : Polyline)
2 (default) : Polyline
3 : (only AP242) Tessellation 2D + Position
4 : (only AP242) Tessellation 3D
5 : From AP242, dual graphics : both a "frozen" Tessellation 3D and a Placeholder are written (will be selected by readers) , only with Semantics

General Information on FDT

DATAKIT Class	STEP Entity	Remarks
(Dtk_Component:)Dtk_Info: Dtk_PMIGlobalStandard	product (id=FDT standard) + document_product_equivalence + product_definition_context_association ..	Fdt Standard : ISO / ASME
(Dtk_Text) length/angle value	measure_representation_item
Dtk_Text:Dtk_Info: DtkPrecision	value_format_type_qualifier	nb of significant digits

Graphic and Textual Data of FDT

Step Write FDT

DATAKIT Class	STEP Entity	Remarks
Dtk_FdtAnnotationSet	draughting_model	graphic part of the annotations attached to the model
Dtk_Fdt (as a symbol)	leader_directed_callout	converted to Dtk_Symbol (graphic mode)
Each graphical item of the 2dEntity	annotation_occurrence or sub-type	Items are : texts, leaders, other geometries
Transformation of the Dtk_Fdt : Dtk_transfo	- Text : position of the text : axis2_placement_3d - others : integrated in 3D coordinates
Writing mode : FDT graphics as polyline	geometric_curve_set + list of polyline	all texts, symbols, leaders, geometries
Writing mode : FDT graphics as /b tessellation	tessellated_geometric_set + list of tessellated_curve_set & complex_triangulated_surface_set	AP242 - all texts, symbols, leaders, geometries
Writing mode : FDT graphics as /b placeholder (from AP242E2)	annotation_placeholder_occurrence with : position, character height, attachment points (leader ends)	AP242E2 - minimal presentation; full presentation to be recomputed by the reader
Writing mode : FDT graphics as /b placeholder (from AP242E3)	annotation_placeholder_occurrence_with_leader_line with : position, character height, points of leader lines	AP242E3 - enhanced placeholder introduced in AP242E3

Geometrical Links of FDT

DATAKIT Class	STEP Entity	Remarks
Dtk_NodeConnector (only within a Part)	shape_aspect + geometric_item_specific_usage (to the 3D) draughting_model_item_association (to the symbol)
Dtk_NodeConnector with Path	component_path_shape_aspect + multi_level_reference_designator	AP242 - monolithic mode only
Dtk_Fdt (Tolerance) with no Geometrical Link	attached to the whole Product

Leader Curve of FDT

DATAKIT Class	STEP Entity	Remarks
Leader Curve : general	- Geometry : a dedicated annotation_curve_occurrence - Terminator : annotation_symbol_occurrence / terminator_symbol
Leader Curve : definition of the terminator	defined_symbol (gathers the definition) designated by the terminator_symbol : - pre_defined_terminator_symbol : type of the terminator - symbol_target : size of the terminator - symbol_style , symbol_colour : style of the terminator (color)
Leader Curve : Geometry	an individual item designated by the annotation_curve_occurrence	see below

Other Geometries of FDT

(only in mode Polyline)

DATAKIT Class	STEP Entity	Remarks
Geometrical Items not Leader Curves	one annotation_curve_occurrence to gather them	designates the item or list of items
style of curve(s) (color, thickness, font)	curve_style , draughting_pre_defined_curve_font	common to the whole annotation
style of point(s) (color, marker)	point_style , pre_defined_marker	common to the whole annotation
case of several Geometrical Items	geometric_curve_set	lists the individual items
each Geometrical Item : Line or Polyline	polyline
each Geometrical Item : Circle or Arc of Circle	circle if complete, or trimmed_curve(circle) if arc

Texts of FDT

(only in mode Character Based)

DATAKIT Class	STEP Entity	Remarks
Dtk_CompositeText : general	annotation_text_occurrence	one per common definition of characters (size ..)
Definition of characters	text_style_with_box_characteristics	(height, width, slant, rotate angle)
Style of the text	test_style_for_defined_font	(color)
case of several Dtk_Text	composite_text	lists the individual texts
each Dtk_Text, general case	text_literal
each Dtk_Text, with a frame	text_literal_with_delineation

Semantic Data of FDT (AP203E2, AP242)

FDT Standard

DATAKIT Class

STEP Entity

Remarks

in Dtk_Component:GetInfos, parameter "Dtk_PMIGlobalStandard"

product + application_context "geometrical dimensioning and tolerancing rpresentation"

document_product_equivalence with name="equivalence" ,
FDT Standard in product.name, see below

defines the FDT Standard (ISO 1101 or ASME Y14)

parameter "Dtk_PMIGlobalStandard" = "ISO"

FDT Standard : ISO

parameter "Dtk_PMIGlobalStandard" = "ASME"

FDT Standard : ASME

Datum Elements

DATAKIT Class	STEP Entity	Remarks
Dtk_Fdt + Dtk_Symbol typed TypeDatum (Simple Datum)	datum + datum_feature	a datum embeds the geometrical link (acts as a shape aspect)
Dtk_Fdt + Dtk_DatumTarget	placed_datum_target_feature
Dtk_Fdt + Dtk_Region	geometry (Dtk_Face) as construction geometry

Geometrical Tolerances

DATAKIT Class	STEP Entity	Remarks
a Dtk_GeometricalTolerance with several Dtk_ToleranceSpecification's	geometric_tolerance_relationship + 1 geometric_tolerance per Dtk_ToleranceSpecification
a Dtk_GeometricalTolerance with one Dtk_ToleranceSpecification	geometric_tolerance with various sub-types	type and other data : see below
type Angularity	angularity_tolerance	+ datum refs required
type Circularity	roundness_tolerance
type CircularRunout	circular_runout_tolerance	+ datum refs required
type Concentricity	concentricity_tolerance	+ datum refs required
type Cylindricity	cylindricity_tolerance
type Flatness	flatness_tolerance
type LineProfile	line_profile_tolerance
type SurfaceProfile	surface_profile_tolerance
type Parallelism	parallelism_tolerance	+ datum refs required
type Perpendicularity	perpendicularity_tolerance	+ datum refs required
type Position	position_tolerance
type Straightness	straightness_tolerance
type Symmetry	symmetry_tolerance	+ datum refs required
type TotalRunout	total_runout_tolerance	+ datum refs required
in the Dtk_ToleranceSpecification : Material Modifier	+ combined sub-type modified_geometric_tolerance + Material Modifier	AP214/AP203E2 - Modifier Ⓛ Ⓜ Ⓡ
in the Dtk_ToleranceSpecification : Material Modifier	+ combined sub-type geometric_tolerance_with_modifiers + list of Material Modifier	AP242 - Modifier Ⓛ Ⓜ Ⓕ u v w x y z ...
in the Dtk_ToleranceSpecification : Tolerance Zone	tolerance_zone + tolerance_zone_form	AP242 - notation diameter before the value
in the Dtk_ToleranceSpecification : Projected Zone	projected_zone_definition	AP242 - notation "Ⓟ with a value"
in the Dtk_ToleranceSpecification : Unequal, if FDT Standard = "ISO"	+ combined sub-type unequally_disposed_geoemtric_tolerance	AP242 - notation "UZ[<i>value</i>]"
in the Dtk_ToleranceSpecification : Unequal, if FDT Standard = "ASME"	+ combined sub-type unequally_disposed_geoemtric_tolerance	AP242 - notation "Ⓤ with a value"
in the Dtk_ToleranceSpecification : defined unit	+ combined sub-type geometric_tolerance_with_defined_unit	notation "/<i>val1[</i>X<i>val2]</i>" after the value
in the Dtk_ToleranceSpecification : maximum value	+ combined sub-type geometric_tolerance_with_maximum_tolerance	AP242 - notation "MAX val" after the value
in the Dtk_ToleranceSpecification : if there are datum(s)	datum_system	for AP242 only
Dtk_ReferenceBlock, to one datum, no modifier	datum_reference	AP214/AP203E2 - Notation A
Dtk_ReferenceBlock, to one datum, with modifier	referenced_modified_datum	AP214-AP203E2 - Notation A + modifier
Dtk_ReferenceBlock, to 2 datums	common_datum + datum_reference or referenced_modified_datum	AP214/AP203E2 - Notation A-B
Dtk_ReferenceBlock, to one datum	datum_reference_compartment	AP242 - Notation A [modifiers]
Dtk_ReferenceBlock, to 2-3 datums	datum_reference_compartment + common_datum_list + 2-3 datum_reference_element	AP242 - Notation A-B

Dimensions

DATAKIT Class	STEP Entity	Remarks
Dtk_Dimension as a size	dimensional_size , angular_size	on one set of 3d items
Dtk_Dimension as a distance	dimensional_location , angular_location	between 2 sets of 3d items
DimensionType of the Dtk_Dimension	field "name" of the dimensional_size or dimensional_location	Chamfer out of scope of the standard
for each value (nominal, mini, maxi, plus, minus)	length_measure_with_unit , plane_angle_measure_with_unit	role : see below
for each value , number of significant digits (when known)	value_format_type_qualifier	determined from Dtk_Info:DtkPrecision
nominal value	one value in the dimension, named "nominal value"
nominal value in a rectangular frame	one value in the dimension + modifier "theoretical"
nominal value between parentheses	one value in the dimension + modifier "auxiliary"
tolerance as plus value and minus value	plus_minus_tolerance + tolerance_value
tolerance as tabulated (standardized text)	plus_minus_tolerance + limits_and_fits
2 values mini-maxi	one value in the dimension, named "lower limit" and "upper limit"
one value "MINI"	one value in the dimension + type_qualifier "minimum"
one value "MAXI"	one value in the dimension + type_qualifier "maximum"
additional : suffix ( Ⓔ Ⓘ )	name of the shape_dimension_representation	resp. "envelope requirement" or "independency"
additional : prefix (CR square), suffix (others)	descriptive_representation_item (text) for modifier

Note as Editable Text

From AP242 - previously ignored (considered as just graphics)

DATAKIT Class	STEP Entity	Remarks
Dtk_Symbol with a list of Dtk_Text	property_definition_representation + property_definition, name = "semantic text"	AP242
list of Dtk_Text	representation + list of descriptive_representation_item	AP242

Associated Data

Construction Geometries

DATAKIT Class	STEP Entity	Remarks
Dtk_AxisSystem	axis2_placement_3d + constructive_geometry_representation + constructive_geometry_representation_relationship
Construction Geometry in the Dtk_FdtAnnotationSet	(this geometry) + constructive_geometry_representation + constructive_geometry_representation_relationship	infinite geometry : only the curve/surface is written
Dtk_Body in a Dtk_Node of sub-type DTK_NODE_FDT	(this geometry) + constructive_geometry_representation + constructive_geometry_representation_relationship	infinite geometry : only the curve/surface is written
Dtk_Body : Infinite Geometry	(this geometry) + constructive_geometry_representation + constructive_geometry_representation_relationship

Views and Captures

DATAKIT Class	STEP Entity	Remarks <! Dtk_FdtView : deprecated - STEP View maps with Dtk_FdtCapture not Dtk_FdtView>
Dtk_FdtCapture	camera_model_d3 + draughting_model	lists the annotations in the view + the 3D main model
Dtk_ModelDisplay	camera_model_d3 + draughting_model	lists the annotations in the view + the 3D main model
Dtk_FdtCapture or Dtk_ModelDisplay with a Clipping Plane	camera_model_d3_multi_clipping + plane + draughting_model	Section View - limited to one clipping plane
parameters of the view	view_volume , planar_box
status "active" of the ModelDisplay	default_model_geometric_view	From AP242E2 - only one per component
in the Dtk_Node : NodeConnector "forceHidden" with instance path	context_dependent_over_riding_styled_item + invisibility listed in the draughting_model
in the root Dtk_Component : Dtk_Override/Dtk_OverrideSet with Dtk_Info (color) and NodeConnector (instance path)	context_dependent_over_riding_styled_item + styled_item(color) listed in the draughting_model	syntax stepw_AddOverrideInstanceInfo

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