AIGraph Blog

About DXF file

  Apr 15, 2013

AutoCAD DXF (Drawing Interchange Format, or Drawing Exchange Format) is a CAD data file format developed by Autodesk for enabling data interoperability between AutoCAD and other programs.DXF was originally introduced in December 1982 as part of AutoCAD 1.0.

Versions of AutoCAD from Release 10 (October 1988) and up support both ASCII and binary forms of DXF. Earlier versions support only ASCII.

The DXF format is a tagged data representation of all the information contained in an AutoCAD drawing file. Tagged data means that each data element in the file is preceded by an integer number that is called a group code.

The DXF Reference is available here.

he basic organization of a DXF file is as follows:

  • HEADER section – General information about the drawing. Each parameter has a variable name and an associated value.
  • CLASSES section – Holds the information for application-defined classes whose instances appear in the BLOCKS, ENTITIES, and OBJECTS sections of the database. Generally does not provide sufficient information to allow interoperability with other programs.
  • TABLES section – This section contains definitions of named items.
    • Application ID (APPID) table
    • Block Record (BLOCK_RECORD) table
    • Dimension Style (DIMSTYPE) table
    • Layer (LAYER) table
    • Linetype (LTYPE) table
    • Text style (STYLE) table
    • User Coordinate System (UCS) table
    • View (VIEW) table
    • Viewport configuration (VPORT) table
  • BLOCKS section – This section contains Block Definition entities describing the entities comprising each Block in the drawing.
  • ENTITIES section – This section contains the drawing entities, including any Block References.
  • OBJECTS section – Contains the data that apply to nongraphical objects, used by AutoLISP and * * * ObjectARX applications.
  • THUMBNAILIMAGE section – Contains the preview image for the DXF file.

DXF is rich in features, including: support for 3D objects,curves, text, associatived imensioning, and is an easy format to parse. The DXB format is a binary representation of a DXF file and they are usually smaller and faster to load than the equivalent DXF file.

AIGraph CAD Viewer supports all version of DXF file format, with batch conversion between DWG and DXF.