TechDraw Preferences

From FreeCAD Documentation


The preferences of the TechDraw Workbench are found in the Preferences Editor, Edit → Preferences → TechDraw.

All preferences settings with italic labels are default values for new drawing objects. They have no effect on existing objects.


General preferences

Drawing Update

  • Update With 3D: Whether or not pages are updated every time the 3D model is changed. This is a global policy setting.
  • Allow Page Override: Whether or not a page's Keep Updated property can override the global Update With 3D parameter. This is a global policy setting.
  • Keep Page Up To Date: Keeps drawing pages in sync with changes of the 3D model in real time. This can slow down the response time.
  • Auto-distribute Secondary Views: Automatically distributes secondary views for projection groups.


  • Label Font: The name of the font for labels. The font is also used for new dimensions, changing it has no effect on existing dimensions.
  • Label Size: Default size for labels.


  • Projection Group Angle: If projection groups will use either first-angle (European) projection or third-angle (American) projection. See multiview projection for an explanation.
  • Section Line Convention: Standard for section lines that controls the position of arrows and symbol (introduced in version 0.22). The options are:
    • ANSI
    • ISO



  • Show Grid: Default Show Grid setting for new pages.
  • Grid Spacing: Default distance between grid lines for new pages.



Scale preferences


  • Page Scale: Default scale for new pages.
  • View Scale Type: Default scale for new views.
  • View Custom Scale: Default scale for views if View Scale Type is Custom.

Size Adjustments

  • Vertex Scale: Scale of vertex dots. Multiplier of line width.
  • Center Mark Scale: Size of center marks. Multiplier of vertex size.
  • Template Edit Mark: Size of template field click handles in mm (green dots).
  • Welding Symbol Scale: Multiplier for size of welding symbols.


Dimensions preferences
  • Standard and Style: The standard to be used for dimensional values. The differences between the standards are shown in the image:
    Differences between the supported standards. (Image source)
ISO Oriented - drawn according to the standard ISO 129-1, text is rotated to be parallel with the dimension line tangent.
ISO Referencing - drawn in compliance with ISO 129-1, text is always horizontal, above the shortest possible reference line.
ASME Inlined - drawn according to the standard ASME Y14.5M, text is horizontal, inserted in a break within the dimension line or arc.
ASME Referencing - drawn in compliance with ASME Y14.5M, text is horizontal, short reference line is attached to one side's vertical center.
  • Use Global Decimals: Use number of decimals from the general preferences.
  • Show Units: Appends the unit (mm, in, etc.) to dimension values.
  • Alternate Decimals: Number of decimals if Use Global Decimals is not selected and Dimension Format not specified.
  • Dimension Format: Custom format for dimension text. Uses the printf format specifier.
  • Font Size: Font size for dimension text.
  • Tolerance Text Scale: Tolerance font size adjustment. Multiplier of dimension Font Size.
  • Diameter Symbol: Character used to indicate diameter dimensions.
  • Arrow Style: Arrowhead style for dimensions.
  • Arrow Size: Arrowhead size of dimensions.
  • Extension Gap Factor - ISO: Gap between dimension point and start of extension lines for ISO dimensions. introduced in version 0.21
  • Extension Gap Factor - ASME: Gap between dimension point and start of extension lines for ASME dimensions. introduced in version 0.21
  • Line Spacing - ISO: Spacing between the dimension line and dimension text for ISO dimensions. introduced in version 0.21


Annotation preferences


  • Section Cut Surface: Style for section cut surface. The options are:
    • Hide: There is no visible surface.
    • Solid Color: The surface gets the color set for Section Face
    • SVG Hatch: The surface is hatched.
    • PAT Hatch: The surface is geometrically hatched.
  • Complex Section Line Marks: Show marks at direction changes on ComplexSection lines. introduced in version 0.21
  • Detail View Outline Shape: Outline shape for detail views. The options are:
    • Circle
    • Square
  • Detail View Show Matting: This checkbox controls whether or not to display the outline around a detail view. introduced in version 0.22
  • Detail Source Show Highlight: This checkbox controls whether or not to display a highlight around the detail area in the detail's source view. introduced in version 0.22
  • Balloon Shape: Shape of balloon annotations.
  • Balloon Leader End: Default style for balloon leader line ends, see balloon properties.
  • Balloon Leader Kink Length: Length of balloon leader line kink.
  • Balloon Orthogonal Triangle: If Balloon Leader End is Filled Triangle, the triangle can only get a vertical or horizontal direction when the balloon is moved.
  • Leader Line Auto Horizontal: Forces last leader line segment to be horizontal.
  • Show Center Marks: Show arc center marks in views.
  • Print Center Marks: Show arc centers in printed output.


  • Line Standard: Standard to be used to draw section lines in section views.
  • Line Width Group: A LineGroup to set the default line widths.
  • Hidden Line Style: Style of hidden lines. introduced in version 0.22
  • Section Line Style: Style for section lines.
  • Detail Highlight Style: Line style of the outline shape for detail views.
  • Center Line Style: Default style for centerlines.
  • Line End Cap Shape: The default (round) should almost always be the right choice. Flat or square caps are useful if you are planning to use a drawing as a 1:1 cutting guide.


Colors preferences

Setup of the default colors for new pages:

  • Normal: Normal line color.
  • Preselected: Preselection color. The color that is used to highlight objects when hovering with the mouse over them.
  • Selected: Color for selected objects.
  • Background: Background color around pages.
  • Dimension: Color of dimension lines and text.
  • Centerline: Color for centerlines.
  • Detail Highlight: Line color for the outline shape of detail views.
  • Grid Color: Color for all page grids.
  • Template Underline: Color for the underline that marks editable texts in templates. introduced in version 0.22
  • Hidden Line: Hidden line color. This color will be used for all kinds of hidden lines.
  • Section Face: Color of the section view cut surface. Only used if the setting Section Cut Surface is set to Solid Color.
  • Section Line: Color of the section view cut line.
  • Hatch: Hatch image color.
  • Geometric Hatch: Geometric hatch pattern color.
  • Vertex: Color of the selectable vertices in views.
  • Leaderline: Color for new leaderlines.
  • Transparent Faces: If checked, object faces will be transparent. Otherwise the set color will be used for faces.
  • Light on dark: If checked text and lines will have a light color. To be used if the Page Color is dark. Transparent or light colored faces are recommended with this option. introduced in version 0.21
  • Monochrome: If checked, the set color will be used for all text and lines. introduced in version 0.21
  • Page Color: The background color of the page. introduced in version 0.21


HLR preferences

HLR stands for hidden line removal.

  • Use Polygon Approximation: Uses an approximation to find hidden lines. This is fast, but the result is a collection of short straight lines.
  • Show Hard Lines: Shows hard and outline edges (visible lines always shown)
  • Show Smooth Lines: Shows smooth lines. A smooth line is a line indicating a change between tangent surfaces, as in the transition from a flat surface to a fillet.
  • Show Seam Lines: Show seam lines. A seam line is a boundary between faces.
  • Show UV ISO Lines: Shows ISO lines. ISO stands for isoparametric. Here is a description what isoparametric lines (in fact curves) are.
  • ISO Count: The number of ISO lines per face edge.


Advanced preferences
  • Detect Faces: If checked, TechDraw will attempt to build faces using the line segments returned by the hidden line removal algorithm. Faces must be detected in order to use hatching, but there can be a performance penalty in complex models.
  • Report Progress: Issue progress messages while building View geometry. introduced in version 0.21
  • Use New Face Finder Algorithm: If checked, the new face finder algorithm will be used instead of the original one. introduced in version 0.21
  • Auto Correct Dimension Refs: If checked, an attempt is made to update dimension references when the model changes. introduced in version 0.21
  • Show Section Edges: Highlights the border of the section cut in section views.
  • Fuse Before Section: Performs a fuse operation on the input shape(s) before Section view processing
  • Allow Crazy Edges: Includes edges with unexpected geometry in results, e.g. zero lengths
  • Debug Section: Dumps intermediate results during a Section view processing
  • Debug Detail: Dumps intermediate results during a Detail view processing
  • Overlap Edges Scrub Passes: The number of attempts to remove overlapping edges returned by the Hidden Line Removal algorithm. A value of 0 indicates no scrubbing. Values above 2 are generally not productive. Each attempt adds to the time required to produce the drawing. introduced in version 0.21
  • Edge Fuzz: Size of selection area around edges. The fuzz unit is approximately 0.1 mm, depending on your current zoom. The default is 10. Values in the 20-30 range will make it noticeably easier to select edges. Large numbers will cause overlaps with other drawing elements.
  • Mark Fuzz: Selection area around center marks. The fuzz unit is approximately 0.1 mm, depending on your current zoom.
  • Max SVG Hatch Tiles: The limit of SVG tiles with a size of 64x64 pixels used to hatch a single face. For large scalings one might get an error about to many SVG tiles, then one needs to increase the tile limit.
  • Max PAT Hatch Segments: The maximum hatch line segments used when hatching a face with a PAT pattern.