DXF Entities and Objects

DXF entities are objects that make up the design data stored in a DXF file.

Graphical Entities

Graphical entities are visible objects stored in blocks, modelspace- or paperspace layouts. They represent the various shapes, lines, and other elements that make up a 2D or 3D design.

Some common types of DXF entities include:

  • LINE and POLYLINE: These are the basic building blocks of a DXF file. They represent straight and curved lines.

  • CIRCLE and ARC: These entities represent circles and portions of circles, respectively.

  • TEXT and MTEXT: DXF files can also contain text entities, which can be used to label parts of the design or provide other information.

  • HATCH: DXF files can also include hatch patterns, which are used to fill in areas with a specific pattern or texture.

  • DIMENSION: DXF files can also contain dimension entities, which provide precise measurements of the various elements in a design.

  • INSERT: A block is a group of entities that can be inserted into a design multiple times by the INSERT entity, making it a useful way to reuse elements of a design.

These entities are defined using specific codes and values in the DXF file format, and they can be created and manipulated by ezdxf.

Objects

DXF objects are non-graphical entities and have no visual representation, they store administrative data, paperspace layout definitions, style definitions for multiple entity types, custom data and objects. The OBJECTS section in DXF files serves as a container for these non-graphical objects.

Some common DXF types of DXF objects include:

  • DICTIONARY: A dictionary object consists of a series of name-value pairs, where the name is a string that identifies a specific object within the dictionary, and the value is a reference to that object. The objects themselves can be any type of DXF entity or custom object defined in the DXF file.

  • XRECORD entities are used to store custom application data in a DXF file.

  • the LAYOUT entity is a DXF entity that represents a single paper space layout in a DXF file. Paper space is the area in a CAD drawing that represents the sheet of paper or other physical media on which the design will be plotted or printed.

  • MATERIAL, MLINESTYLE, MLEADERSTYLE definitions stored in certain DICTIONARY objects.

  • A GROUP entity contains a list of handles that refer to other DXF entities in the drawing. The entities in the group can be of any type, including entities from the model space or paper space layouts.

TagStorage

The ezdxf package supports many but not all entity types, all these unsupported types are stored as TagStorage instances to preserve their data when exporting the edited DXF content by ezdxf.

Access Entity Attributes

All DXF attributes are stored in the entity namespace attribute dxf.

print(entity.dxf.layer)

Some attributes are mandatory others are optional in most cases a reasonable values will be returned as default value if the attribute is missing.

See also

Tutorial for Getting Data from DXF Files

Where to Look for Entities

The DXF document has an entity database where all entities which have a handle are stored in a (key, value) storage. The query() method is often the easiest way to request data:

for text in doc.entitydb.query("TEXT"):
    print(text.dxf.text)

See also

Graphical entities are stored in blocks, the modelspace or paperspace layouts.

  • The doc.modelspace() function returns the Modelspace instance

  • The doc.paperspace() returns a Paperspace instance

  • The doc.blocks attribute provides access to the BlocksSection

The query() method of the Drawing class which represents the DXF document, runs the query on all layouts and block definitions.

Non-graphical entities are stored in the OBJECTS section:

Resource definitions like Layer, Linetype or Textstyle are stored in resource tables:

Important

A layer assignment is just an attribute of a DXF entity, it’s not an entity container!

See also

How to Create Entities

The recommended way to create new DXF entities is to use the factory methods of layouts and blocks to create entities and add them to the entity space automatically.

See also