DXF

DXF (Drawing Interchange Format) is Autodesk’s open exchange format for CAD data. LinkCAD supports all DXF versions from Release 12 through 2018.

Format Summary

Property	Value
Extensions	.dxf
Encoding	ASCII or Binary
Import	✓
Export	✓
License	Basic
Hierarchy	BLOCK/INSERT with scale and rotation
Layers	Named layers with colors

Supported Entity Types

Entity	Import	Export	Notes
LINE	✓	✓	Basic line segments
POLYLINE	✓	✓	2D/3D with width and bulge arcs
LWPOLYLINE	✓	✓	Lightweight polylines (R14+)
ARC	✓	✓	Circular arcs
CIRCLE	✓	✓	Complete circles
ELLIPSE	✓	✓	Elliptical arcs and full ellipses
SPLINE	✓	✓	Approximated to polylines
TEXT	✓	✓	Single-line text
MTEXT	✓	✓	Multi-line text
INSERT	✓	✓	Block references with scale/rotation
REGION	✓	✓	Filled regions with hole detection
HATCH	✓	✓	Configurable import mode
SOLID	✓	✓	Filled triangular/quad areas
POINT	✓	✓	Configurable display modes

Import Options

Units & Scaling

Option	Description	Default
Units value	Physical units per DXF unit	1
Units type	Microns, millimeters, inches, etc.	Micron
Scaling	Additional scaling multiplier	1.0

Arc Resolution

Option	Description	Default
Precision	Tolerance, DPI, or segments/360° for arc conversion	32 segments/360°

Entity Handling

Option	Description	Default
Ignore text	Skip TEXT/MTEXT entities	Off
Keep closed zero-width polylines as polylines	Import valid closed zero-width POLYLINE/LWPOLYLINE entities as closed polylines instead of polygons	Off
Text line width	Stroke width for text (0 = relative)	0.0
HATCH processing	On HATCH layer / Separate layer / Skip	On HATCH layer
Polyface mesh	Import polyface mesh entities	Off
Polyline end caps	Flat, Round, or Square extended	Flat
Resolve layers	Obey BYBLOCK/BYLAYER attributes	Off

Point Import

Option	Description	Default
Import points	Import POINT entities	On
Point mode	Dot, Cross (+), X-Cross (×), Tick	X-Cross
Point size	Marker size in drawing units	1.0

Export Options

File Format

Option	Description	Default
DXF version	Release 12, 14, 2000, or Abaqus	2000
Binary DXF	Write binary instead of ASCII	Off

Geometry

Option	Description	Default
Fill polygons	Fill zero-width polygons using SOLID entities	Off
Export as regions	Use REGION entities with hole detection	Off
Hatch polygons	Export polygons as hatched areas	Off
Explode text	Convert text to polyline outlines	Off
Flatten hierarchy	Remove blocks, write flat geometry	Off
Explode arrays	Write array instances as separate inserts	Off

Units & Precision

Option	Description	Default
Units value	Physical units per DXF unit	1
Units type	Target unit system	Micron
Scaling	Additional scaling multiplier	1.0
End cap type	Round, Flat, or Square for polyline caps	Round

Export Version Compatibility

Version	Max Name Length	Character Set	Notes
Release 12	31 characters	Alphanumeric + $_-	Maximum legacy compatibility
Release 14	255 characters	Extended	Enhanced polyline support
Release 2000	255 characters	Unicode	Recommended for most use cases
Abaqus	—	—	Special FEA export format

Common Workflows

GDSII → DXF

Standard IC-to-mechanical conversion. Set DXF output units to match your target CAD system.

DXF → GDSII

Convert mechanical drawings to IC mask layout. Layer names map to GDSII layer numbers via layer maps.

DXF → Gerber

Generate photoplotter output from DXF mechanical drawings.

Technical Notes

• DXF files are inherently unitless — the unit interpretation depends on application settings
• Arc-to-polyline conversion quality is controlled by the precision settings
• The Keep closed zero-width polylines as polylines option preserves valid closed zero-width DXF polylines as editable closed polylines; malformed or self-touching closed contours are imported as open outlines for robustness
• HATCH entities can be placed on their own layer or the HATCH-designated layer
• Block names longer than 31 characters are automatically truncated when exporting to R12
• Binary DXF is more compact but less portable than ASCII DXF

CLI / Command-File Options

These option keys can be used on the command line (e.g. --DxfOutScaling 1000) or in command files (e.g. DxfOutScaling=1000).

Import

Key	Type	Description
DxfInScaling	float	Import scaling factor
DxfInUnitsUnit	int	Unit enum (see Units)
DxfInUnitsValue	int	Units scaling value
DxfInEndcapType	int	Wire endcap style — 0=round, 1=flat, 2=square extended
DxfInExplodeSplines	flag	Explode splines to polylines
DxfInHatchProcessing	int	Hatch mode — 0=ignore, 1=import on separate layer, 2=fill
DxfInIgnoreText	flag	Ignore TEXT/MTEXT entities
DxfInImportPoints	flag	Import POINT entities
DxfInKeepClosedZeroWidthPolylinesAsPolylines	flag	Keep valid closed zero-width DXF polylines as polylines instead of polygons
DxfInPointMode	int	Point display mode (PDMODE bit field: base 0=none, 1=dot, 2=cross, 3=x, 4=diamond; add 32 for circle, 64 for square)
DxfInPointSize	float	Point size in drawing units (PDSIZE)
DxfInReadPolyfaceMesh	flag	Read polyface mesh entities
DxfInTextLineWidth	float	Text stroke width

Export

Key	Type	Description
DxfOutScaling	float	Export scaling factor
DxfOutUnitsUnit	int	Unit enum (see Units)
DxfOutUnitsValue	int	Units scaling value
DxfOutFormatVersion	int	DXF version — 0=DXF 12 Abaqus, 12=DXF 12, 14=DXF 14, 2000=DXF 2000
DxfOutBinary	flag	Write binary DXF format
DxfOutEndcapType	int	Wire endcap style — 0=round, 1=flat, 2=square extended
DxfOutExplodeArrays	flag	Explode array references
DxfOutExplodeText	flag	Explode text to polylines
DxfOutExportAsRegions	flag	Export polygons as REGION entities
DxfOutFillPolygons	flag	Fill polygons with SOLID entities
DxfOutFlatten	flag	Flatten hierarchy
DxfOutHatchPolygons	flag	Hatch polygons