Autodesk AutoCAD DWG/DXF Writer Parameters

Attribute Output

This parameter specifies the default manner in which attribute data will be stored. Note that storing attributes may greatly increase the size of the output AutoCAD file.

Extended Entity Data

Attribute: extended_entity_data

If selected, attempts to store schema attributes on a layer as extended entity data. For more information, see Extended Entity Data.


Specifies whether the writer should attempt to store schema attributes on a layer as insert attributes for block insert features, or new block features.

If selected, when it creates the inserts, the writer attempts to add the schema attributes defined by the layer definition. In this case, any format specific insert attributes in the fme_attrib_info list attributes are ignored.

If not selected, the writer attempts to write fme_attrib_info list attributes (added by the AutoCAD reader) as insert attributes. Note that this is only done if the autocad_attributes_follow attribute is set. The AutoCAD reader automatically sets this attribute.

Limited (default)

Attribute: external_attributes

Instructs the writer to not store any attribution in the AutoCAD file, with the exception of extended entity data list formatted.

Insert attributes may also be created for insert entities, from fme_attrib_info list, if the autocad_attributes_follow attribute is set.

File Options

AutoCAD Version

Specify the AutoCAD release that will be compatible with the output file.


Default Application Name

The application name that is used when writing extended entity data.

Output Defined Attributes Only

When this parameter is set to Yes (default), only those attributes defined as part of the layer definition will be stored.

If this parameter is set to No, most feature attributes (except those that start with autocad) are stored.

AutoCAD Shape File Folder

Specifies the folder in which to look for shape files (*.shp) from which information about SHAPE entities will be extracted for writing. For more information, see Shapes.

Created Block Name Prefix

The names of blocks created by the writer during automatic block creation.

This parameter may be used to specify a prefix for block names that are created by the writer during automatic block generation. Automatic block generation occurs for features written with aggregate and other geometries which are best represented by block entities.

This parameter is only used when Use the Block Name to Create Blocks parameter is set to No, and is not used for features that already have an autocad_block_name attribute specified.

The names of created blocks will take the form:

<Block Name Prefix>_<blocknumber>

Audit and Fix Errors

Note  This parameter is not supported by the RealDWG writer.

Use this parameter to turn on/off internal auditing before the final drawing file is written out.

By default it is set to Yes, so auditing will be performed and any errors found will be fixed. It is recommended that you leave the auditing set to Yes. If you set it to No, it is possible that the output file may not be as per the AutoCAD file specification.

How Auditing Fixes Errors: As an example, if there is a layer name with a space or any other invalid characters, then that layer name will be changed to something like $DDT_AUDIT_GENERATED_(3B). If auditing is turned off, then the layer name will not be changed and when it is audited in AutoCAD, it will return errors such as invalid layer names.

Coordinate System Storage

This parameter controls whether the writer will optionally store the coordinate system of its features. The coordinate system can be stored inside the output AutoCAD file as an Esri Well Known Text (in an ESRI_PRJ entry in an internal dictionary in the file), according to Esri specifications. It can also be stored externally in a companion Esri .prj file that shares the output AutoCAD file's base name, but has a .prj extension. Lastly, it can be stored internally using the native Coordinate System storage which will be recognized by the native AutoCAD application.


  • None (projection information is not stored anywhere)
  • External PRJ
  • Internal Native
  • Internal WKT

AutoCAD data files written this way with projection information will be recognized by FME and the free ArcGIS for AutoCAD application, which installs on top of the AutoCAD application.

Use the block name to create blocks

Note  This parameter is not supported by the RealDWG writer.

The names of blocks created by the writer during automatic block creation will use the value of the autocad_block_name attribute if the attribute is present and this parameter is specified.

If a template file is used during writing, the block name will be used to try to match an existing block definition in the template file. This is similar to the behavior for insert entity writing. This parameter does not affect the use of the block name for insert entity writing.

If the intention is that only insert entities should be used to try to match block names with block definitions, set this parameter to No.

If not specified, the syntax may be the following, but may also be modified by the usage of the Created Block Name Prefix parameter:


Purge Unused Objects

This parameter can be used to toggle purging of unused objects or entities before the final drawing file is written out.

Unused objects are those which are not referenced by other objects in the drawing. For example, for a layer to be eligible to be purged, there must be no entities on that layer.

If set to Yes, the AutoCAD writer will attempt to purge the following object types:

  • Blocks
  • Layers
  • Detail View Styles
  • Dimension Styles
  • Groups
  • Linetypes
  • Materials
  • MLine Styles
  • MLeader Styles
  • Registered Applications
  • Section View Styles
  • Table Styles
  • Text Styles
  • Visual Styles

Insertion Scale Units

This parameter can be used to set the INSUNITS variable of the destination dataset to one of the following units:

  • Inches
  • Feet
  • Miles
  • Millimeters
  • Centimeters
  • Meters
  • Kilometers
  • Microinches
  • Mils
  • Yards
  • Angstroms
  • Nanometers
  • Microns
  • Decimeters
  • Dekameters
  • Hectometers
  • Gigameters
  • Astronomical
  • Lightyears
  • Parsecs

When this parameter is not set, the INSUNITS variable is taken from a template file, if specified. The INSUNITS variable specifies the drawing units used in the scaling of inserted entities such as blocks.

This parameter behaves like a declaration of the type of units, but it does not change the scale or coordinates of existing entities, nor does it affect any entities to be written by the AutoCAD writer.

Write Thumbnail Image

This parameter can be set to Yes to create a thumbnail image of the destination drawing model space within the destination drawing file. This image may then be used as a preview by enabled applications, such as Windows Explorer.

Prefer writing donuts as hatches

This parameter can be used to change how donut geometries on features with autocad_entity attributes not set to autocad_hatch or autocad_mpolygon, are represented as AutoCAD entities.

If this parameter is set to Yes, and a donut is planar, then it will be written as a hatch entity. Donuts with three dimensions will only be written as hatches if they have a constant Z value, which can be stored as the hatch elevation.

If a donut is not oriented in the XY plane, then the feature must have autocad_extrusion_x, autocad_extrusion_y, and autocad_extrusion_z attributes set which indicate the normal vector direction, orthogonal to the plane of the object. If not, the hatch may have Z values dropped, to force it into the XY plane.

If this parameter is set to No, or a donut is not planar, then that donut will be handled like a multi-area geometry, and will be written as a block.