Dimension

The DIMENSION entity (DXF Reference) represents several types of dimensions in many orientations and alignments. The basic types of dimensioning are linear, radial, angular, ordinate, and arc length.

For more information about dimensions see the online help from AutoDesk: About the Types of Dimensions

Important

The DIMENSION entity is reused to create dimensional constraints, such entities do not have an associated geometrical block nor a dimension type group code (2) and reside on layer *ADSK_CONSTRAINTS. Use property Dimension.is_dimensional_constraint to check for this objects. Dimensional constraints are not documented in the DXF reference and not supported by ezdxf.

See also

Subclass of

ezdxf.entities.DXFGraphic

DXF type

'DIMENSION'

factory function

see table below

Inherited DXF attributes

Common graphical DXF attributes

Factory Functions

Linear and Rotated Dimension (DXF)

add_linear_dim()

Aligned Dimension (DXF)

add_aligned_dim()

Angular Dimension (DXF)

add_angular_dim_2l()

Angular 3P Dimension (DXF)

add_angular_dim_3p()

Angular Dimension by center, radius, angles

add_angular_dim_cra()

Angular Dimension by ConstructionArc

add_angular_dim_arc()

Diameter Dimension (DXF)

add_diameter_dim()

Radius Dimension (DXF)

add_radius_dim()

Ordinate Dimension (DXF)

add_ordinate_dim()

Warning

Do not instantiate entity classes by yourself - always use the provided factory functions!

class ezdxf.entities.Dimension

There is only one Dimension class to represent all different dimension types.

dxf.version

Version number: 0 = R2010. (int, DXF R2010)

dxf.geometry

Name of the BLOCK that contains the entities that make up the dimension picture.

For AutoCAD this graphical representation is mandatory, otherwise AutoCAD will not open the DXF document. BricsCAD will render the DIMENSION entity by itself, if the graphical representation is not present, but displays the BLOCK content if present.

dxf.dimstyle

Dimension style (DimStyle) name as string.

dxf.dimtype

Values 0-6 are integer values that represent the dimension type. Values 32, 64, and 128 are bit values, which are added to the integer values.

0

Linear and Rotated Dimension (DXF)

1

Aligned Dimension (DXF)

2

Angular Dimension (DXF)

3

Diameter Dimension (DXF)

4

Radius Dimension (DXF)

5

Angular 3P Dimension (DXF)

6

Ordinate Dimension (DXF)

8

subclass ezdxf.entities.ArcDimension introduced in DXF R2004

32

Indicates that graphical representation geometry is referenced by this dimension only. (always set in DXF R13 and later)

64

Ordinate type. This is a bit value (bit 7) used only with integer value 6. If set, ordinate is X-type; if not set, ordinate is Y-type

128

This is a bit value (bit 8) added to the other dimtype values if the dimension text has been positioned at a user-defined location rather than at the default location
dxf.defpoint

Definition point for all dimension types. (3D Point in WCS)

  • Linear- and rotated dimension: dxf.defpoint specifies the dimension line location.

  • Arc- and angular dimension: dxf.defpoint and dxfdefpoint4 specify the endpoints of the line used to determine the second extension line.

dxf.defpoint2

Definition point for linear- and angular dimensions. (3D Point in WCS)

  • Linear- and rotated dimension: The dxf.defpoint2 specifies the start point of the first extension line.

  • Arc- and angular dimension: The dxf.defpoint2 and dxf.defpoint3 specify the endpoints of the line used to determine the first extension line.

dxf.defpoint3

Definition point for linear- and angular dimensions. (3D Point in WCS)

  • Linear- and rotated dimension: The dxf.defpoint3 specifies the start point of the second extension line.

  • Arc- and angular dimension: The dxf.defpoint2 and dxf.defpoint3 specify the endpoints of the line used to determine the first extension line.

dxf.defpoint4

Definition point for diameter-, radius-, and angular dimensions. (3D Point in WCS)

The dxf.defpoint and dxf.defpoint4 specify the endpoints of the line used to determine the second extension line for arc- and angular dimension:

dxf.defpoint5

This point defines the location of the arc for angular dimensions. (3D Point in OCS)

dxf.angle

Rotation angle of linear and rotated dimensions in degrees. (float)

dxf.leader_length

Leader length for radius and diameter dimensions. (float)

dxf.text_midpoint

Middle point of dimension text. (3D Point in OCS)

dxf.insert

Insertion point for clones of a linear dimensions. (3D Point in OCS)

This value translates the content of the associated anonymous block for cloned linear dimensions, similar to the insert attribute of the Insert entity.

dxf.attachment_point

Text attachment point (int, DXF R2000), default value is 5.

1

Top left

2

Top center

3

Top right

4

Middle left

5

Middle center

6

Middle right

7

Bottom left

8

Bottom center

9

Bottom right
dxf.line_spacing_style

Dimension text line-spacing style (int, DXF R2000), default value is 1.

1

At least (taller characters will override)

2

Exact (taller characters will not override)
dxf.line_spacing_factor

Dimension text-line spacing factor. (float, DXF R2000)

Percentage of default (3-on-5) line spacing to be applied. Valid values range from 0.25 to 4.00.

dxf.actual_measurement

Actual measurement (float, DXF R2000), this is an optional attribute and often not present. (read-only value)

dxf.text

Dimension text explicitly entered by the user (str), default value is an empty string.

If empty string or “<>”, the dimension measurement is drawn as the text, if ” ” (one blank space), the text is suppressed. Anything else will be displayed as the dimension text.

dxf.oblique_angle

The optional dxf.oblique_angle defines the angle of the extension lines for linear dimension.

dxf.text_rotation

Defines is the rotation angle of the dimension text away from its default orientation (the direction of the dimension line). (float)

dxf.horizontal_direction

Indicates the horizontal direction for the dimension entity (float).

This attribute determines the orientation of dimension text and lines for horizontal, vertical, and rotated linear dimensions. This value is the negative of the angle in the OCS xy-plane between the dimension line and the OCS x-axis.

property dimtype: int

dxf.dimtype without binary flags (32, 62, 128).

property is_dimensional_constraint: bool

Returns True if the DIMENSION entity is a dimensional constraint object.

get_dim_style() → DimStyle

Returns the associated DimStyle entity.

get_geometry_block() → Optional[BlockLayout]

Returns BlockLayout of associated anonymous dimension block, which contains the entities that make up the dimension picture. Returns None if block name is not set or the BLOCK itself does not exist

get_measurement() → Union[float, Vec3]

Returns the actual dimension measurement in WCS units, no scaling applied for linear dimensions. Returns angle in degrees for angular dimension from 2 lines and angular dimension from 3 points. Returns vector from origin to feature location for ordinate dimensions.

override() → DimStyleOverride

Returns the DimStyleOverride object.

render() → None

Renders the graphical representation of the DIMENSION entity as DXF primitives (TEXT, LINE, ARC, …) into an anonymous content BLOCK.

transform(m: Matrix44) → Dimension

Transform the DIMENSION entity by transformation matrix m inplace.

Raises NonUniformScalingError() for non uniform scaling.

virtual_entities() → Iterator[DXFGraphic]

Yields the graphical representation of the anonymous content BLOCK as virtual DXF primitives (LINE, ARC, TEXT, …).

These virtual entities are located at the original location of the DIMENSION entity, but they are not stored in the entity database, have no handle and are not assigned to any layout.

explode(target_layout: Optional[BaseLayout] = None) → EntityQuery

Explodes the graphical representation of the DIMENSION entity as DXF primitives (LINE, ARC, TEXT, …) into the target layout, None for the same layout as the source DIMENSION entity.

Returns an EntityQuery container containing all DXF primitives.

Parameters

target_layout – target layout for the DXF primitives, None for same layout as source DIMENSION entity.

DimStyleOverride

All of the DimStyle attributes can be overridden for each Dimension entity individually.

The DimStyleOverride class manages all the complex dependencies between DimStyle and Dimension, the different features of all DXF versions and the rendering process to create the Dimension picture as BLOCK, which is required for AutoCAD.

class ezdxf.entities.DimStyleOverride
dimension

Base Dimension entity.

dimstyle

By dimension referenced DimStyle entity.

dimstyle_attribs

Contains all overridden attributes of dimension, as a dict with DimStyle attribute names as keys.

__getitem__(key: str) → Any

Returns DIMSTYLE attribute key, see also get().

__setitem__(key: str, value: Any) → None

Set DIMSTYLE attribute key in dimstyle_attribs.

__delitem__(key: str) → None

Deletes DIMSTYLE attribute key from dimstyle_attribs, ignores KeyErrors silently.

get(attribute: str, default: Any = None) → Any

Returns DIMSTYLE attribute from override dict dimstyle_attribs or base DimStyle.

Returns default value for attributes not supported by DXF R12. This is a hack to use the same algorithm to render DXF R2000 and DXF R12 DIMENSION entities. But the DXF R2000 attributes are not stored in the DXF R12 file! This method does not catch invalid attribute names! Check debug log for ignored DIMSTYLE attributes.

pop(attribute: str, default: Any = None) → Any

Returns DIMSTYLE attribute from override dict dimstyle_attribs and removes this attribute from override dict.

update(attribs: dict) → None

Update override dict dimstyle_attribs.

Parameters

attribs – dict of DIMSTYLE attributes

commit() → None

Writes overridden DIMSTYLE attributes into ACAD:DSTYLE section of XDATA of the DIMENSION entity.

get_arrow_names() → tuple[str, str]

Get arrow names as strings like ‘ARCHTICK’ as tuple (dimblk1, dimblk2).

set_arrows(blk: Optional[str] = None, blk1: Optional[str] = None, blk2: Optional[str] = None, ldrblk: Optional[str] = None, size: Optional[float] = None) → None

Set arrows or user defined blocks and disable oblique stroke as tick.

Parameters

  • blk – defines both arrows at once as name str or user defined block

  • blk1 – defines left arrow as name str or as user defined block

  • blk2 – defines right arrow as name str or as user defined block

  • ldrblk – defines leader arrow as name str or as user defined block

  • size – arrow size in drawing units

set_tick(size: float = 1) → None

Use oblique stroke as tick, disables arrows.

Parameters

size – arrow size in daring units

set_text_align(halign: Optional[str] = None, valign: Optional[str] = None, vshift: Optional[float] = None) → None

Set measurement text alignment, halign defines the horizontal alignment, valign defines the vertical alignment, above1 and above2 means above extension line 1 or 2 and aligned with extension line.

Parameters

  • halign – left, right, center, above1, above2, requires DXF R2000+

  • valign – above, center, below

  • vshift – vertical text shift, if valign is center; >0 shift upward, <0 shift downwards

set_tolerance(upper: float, lower: Optional[float] = None, hfactor: Optional[float] = None, align: Optional[MTextLineAlignment] = None, dec: Optional[int] = None, leading_zeros: Optional[bool] = None, trailing_zeros: Optional[bool] = None) → None

Set tolerance text format, upper and lower value, text height factor, number of decimal places or leading and trailing zero suppression.

Parameters

  • upper – upper tolerance value

  • lower – lower tolerance value, if None same as upper

  • hfactor – tolerance text height factor in relation to the dimension text height

  • align – tolerance text alignment enum ezdxf.enums.MTextLineAlignment

  • dec – Sets the number of decimal places displayed

  • leading_zeros – suppress leading zeros for decimal dimensions if False

  • trailing_zeros – suppress trailing zeros for decimal dimensions if False

set_limits(upper: float, lower: float, hfactor: Optional[float] = None, dec: Optional[int] = None, leading_zeros: Optional[bool] = None, trailing_zeros: Optional[bool] = None) → None

Set limits text format, upper and lower limit values, text height factor, number of decimal places or leading and trailing zero suppression.

Parameters

  • upper – upper limit value added to measurement value

  • lower – lower limit value subtracted from measurement value

  • hfactor – limit text height factor in relation to the dimension text height

  • dec – Sets the number of decimal places displayed, requires DXF R2000+

  • leading_zeros – suppress leading zeros for decimal dimensions if False, requires DXF R2000+

  • trailing_zeros – suppress trailing zeros for decimal dimensions if False, requires DXF R2000+

set_text_format(prefix: str = '', postfix: str = '', rnd: Optional[float] = None, dec: Optional[int] = None, sep: Optional[str] = None, leading_zeros: Optional[bool] = None, trailing_zeros: Optional[bool] = None) → None

Set dimension text format, like prefix and postfix string, rounding rule and number of decimal places.

Parameters

  • prefix – dimension text prefix text as string

  • postfix – dimension text postfix text as string

  • rnd – Rounds all dimensioning distances to the specified value, for instance, if DIMRND is set to 0.25, all distances round to the nearest 0.25 unit. If you set DIMRND to 1.0, all distances round to the nearest integer.

  • dec – Sets the number of decimal places displayed for the primary units of a dimension. requires DXF R2000+

  • sep – “.” or “,” as decimal separator

  • leading_zeros – suppress leading zeros for decimal dimensions if False

  • trailing_zeros – suppress trailing zeros for decimal dimensions if False

set_dimline_format(color: Optional[int] = None, linetype: Optional[str] = None, lineweight: Optional[int] = None, extension: Optional[float] = None, disable1: Optional[bool] = None, disable2: Optional[bool] = None)

Set dimension line properties.

Parameters

  • color – color index

  • linetype – linetype as string

  • lineweight – line weight as int, 13 = 0.13mm, 200 = 2.00mm

  • extension – extension length

  • disable1 – True to suppress first part of dimension line

  • disable2 – True to suppress second part of dimension line

set_extline_format(color: Optional[int] = None, lineweight: Optional[int] = None, extension: Optional[float] = None, offset: Optional[float] = None, fixed_length: Optional[float] = None)

Set common extension line attributes.

Parameters

  • color – color index

  • lineweight – line weight as int, 13 = 0.13mm, 200 = 2.00mm

  • extension – extension length above dimension line

  • offset – offset from measurement point

  • fixed_length – set fixed length extension line, length below the dimension line

set_extline1(linetype: Optional[str] = None, disable=False)

Set attributes of the first extension line.

Parameters

  • linetype – linetype for the first extension line

  • disable – disable first extension line if True

set_extline2(linetype: Optional[str] = None, disable=False)

Set attributes of the second extension line.

Parameters

  • linetype – linetype for the second extension line

  • disable – disable the second extension line if True

set_text(text: str = '<>') → None

Set dimension text.

  • text = ” ” to suppress dimension text

  • text = “” or “<>” to use measured distance as dimension text

  • otherwise display text literally

shift_text(dh: float, dv: float) → None

Set relative text movement, implemented as user location override without leader.

Parameters

  • dh – shift text in text direction

  • dv – shift text perpendicular to text direction

set_location(location: UVec, leader=False, relative=False) → None

Set text location by user, special version for linear dimensions, behaves for other dimension types like user_location_override().

Parameters

  • location – user defined text location

  • leader – create leader from text to dimension line

  • relative – location is relative to default location.

user_location_override(location: UVec) → None

Set text location by user, location is relative to the origin of the UCS defined in the render() method or WCS if the ucs argument is None.

render(ucs: Optional[UCS] = None, discard=False) → BaseDimensionRenderer

Starts the dimension line rendering process and also writes overridden dimension style attributes into the DSTYLE XDATA section. The rendering process “draws” the graphical representation of the DIMENSION entity as DXF primitives (TEXT, LINE, ARC, …) into an anonymous content BLOCK.

You can discard the content BLOCK for a friendly CAD applications like BricsCAD, because the rendering of the dimension entity is done automatically by BricsCAD if the content BLOCK is missing, and the result is in most cases better than the rendering done by ezdxf.

AutoCAD does not render DIMENSION entities automatically, therefore I see AutoCAD as an unfriendly CAD application.

Parameters

  • ucs – user coordinate system

  • discard – discard the content BLOCK created by ezdxf, this works for BricsCAD, AutoCAD refuses to open DXF files containing DIMENSION entities without a content BLOCK

Returns

The rendering object of the DIMENSION entity for analytics