DXF

• DXF stands for Drawing Interchange Format
• DXF is a pure 2D format.
• DXF is introduced in 1982 as part of AutoCAD.
• DXF files are ASCII text based.
• DXF files are used to create the blue print of structure.
• DXF files are compatible with every device.

DXF File Structure:

• Structue of a DXF file is a sequence of a groups.
• Each of which occupies two lines in the plain text DXF file.
• Each section start with 0 and end with zero.
• Below are the sections present in a file.

• Header : 

• This section always comes first in DXF file.
• This section containg general information about the drawing.
• Consists of an AutoCAD database version and number of system variables.

• Classes:

• Holds the information for application-defined classes.
• Whose instances appear in the blocks,entities and objects.

• Tables:

• Holds various tables that support functionality of a CAD application 

• Blocks:

• Contains block definition and drawing entities that make up each block reference in the drawing.

• Entities:

• These include simple graphical entity types such as LINE, CIRCLE, VERTEX, etc.

• Objects:

• Contains the graphical objects in the drawing, including block references.

• Thumbnail Image: 

• Contains the preview image details.
• This is the optional section.