What is a DXF file? Things to know about Drawing Interchange File Format files
While various image formats, such as JPEG, PNG, SVG or GIF, are typically known at least rudimentarily even to technical laypeople, the DXF format is far more specialized. The abbreviation "DXF" stands for "Drawing Interchange File Format" , which already gives a good view of the practical application of the file type: The format was explicitly developed by the software developer Autodesk to enable uncomplicated data exchange between different CAD programs.
CAD software is used, for example, for technical documentation or geometric models, so there are overlaps with the use of the DXF file type. More good news first: Our Mr Beam laser cutter is able to process DXF files - to give you even more flexibility and easy data exchange within your project.
DXF files are vector files, but one major difference sets them apart from comparable file formats. The DXF file does not save any pixel-based grids and therefore no individual pixels of an image, but instead a detailed description of the respective image elements - for example lines, line widths, effects or individual objects. The DXF file is therefore suitable for displaying both 2D and 3D drawings. So it is not a pixel graphic , but a vector graphic .
Advantages of DXF files in everyday practice
Although the format saw the light of day in the digital world more than 40 years ago , namely in December 1982, it is still used today without restrictions - this ensures planning security and also underlines the importance of the DXF files.
Other advantages of handling DXF files should not go unmentioned at this point, including these, for example:
- the file format is open source, i.e. generally free and accessible free of charge
- Developer and main responsible for the file format, the US company Autodesk, is still constantly updating the file format
- You, together with your team or other people involved in the project, are completely free to choose your preferred CAD program
- DXF files are vector files, so they can be scaled precisely and flexibly without having to accept any loss of quality in the display
Compatibility with all common CAD software is undoubtedly the greatest strength of the file format - which is not surprising, after all, the file format was developed explicitly for this. The founder of the file format and at the same time founder of the Autodesk company, John Walker, emphasizes this advantage in the name "Drawing Interchange File Format". The naming of the file format attracted more attention at the beginning of the 1980s, since Walker explicitly resisted naming the format "Data exchange format" - which he wanted to avoid confusion with the spreadsheet editing program that was common at the time.
Application areas of DXF files
We pointed out at the beginning that our Mr Beam laser cutter also supports DXF files. All possible applications of our innovative laser machine can therefore be transferred to the file format itself. Furthermore, the file format is preferred, for example, for many technical drawings and sporadically for 3D models.
The DXF file can also support teamwork due to its uncomplicated exchange and high compatibility with CAD programs. It is used, for example, to create descriptions for various modules, create detailed technical and graphic representations or design product designs. The file format is also used sporadically for design drafts. At this point, however, a differentiation from the DWG file format is necessary, which brings with it a greater variety of colours and flexibility - which limits the use purely for design drafts with regard to the DXF file.
In addition to specialized areas of application, the biggest practical advantage that the format brings with it is the ease of collaboration. There is no question about the preferred CAD software of other team members and partners, at the same time everyone involved can be sure that the other members in the project can edit the file with the CAD software of their choice without restrictions. This is an important advantage, especially across professions, because architects, for example, usually use different software than technical draftsmen, but both professions consistently work on each other - thanks to the DXF file and its software independence, this is no longer a problem.
Design and structure of the DXF file
DXF files use a block structure. The structure is therefore divided into several blocks, each of which is clearly visible and clearly separated from one another. Keywords can be added to the individual blocks for a better overview and faster navigation.
Overall, the structure uses four blocks:
- Head
- tables
- blocks/entities
- geometry
All necessary content and other additional information is stored in these individual blocks.
The head defines the fundamental properties of the work environment. These are, for example, parameters for the position or the ability to associate the dimensions. The information is also commonly referred to as meta information.
Information on different elements is recorded in the tables . These are, for example, the line width or the colour. Information on the final visualization on screens is also included in this area, as well as paper areas to be used.
The blocks contain information about the individual elements, which in turn together form the blocks. The file format itself is optimized by combining related information, for example hatching or freely definable geometric elements. The information stored in "ENTITIES" as they are called in the DXF file format is the actual vector information. In this file format, vectors are written in the form of floats, i.e. as floating-point numbers. Logical elements, on the other hand, are numbered by integers, making them individually addressable for all members of the team.
In the geometry part, there is space for the geometric shapes to be used, such as circles, polygons or simple lines. Attributes such as line type or line width can also be found there. In practice, the necessary information in this area is usually kept relatively minimalist in order to avoid problems with the display in advance.
Objects found particularly frequently in a DXF file
Lines, circles, polylines and other geometric shapes make up most of the file content in a DXF file. The respective CAD software that opens the file type enables further processing and discloses the information.
How to create and edit DXF files?
As already mentioned several times in this article, the greatest strength of the file format is its compatibility with all common CAD software . This goes hand in hand with the advantage that you can open, create and edit DXF files with just about any CAD software. Likewise, there is no dependency on individual operating systems within a project and team. Pure viewing programs, such as DWG TrueView, also developed by Autodesk, normally also allow a DXF file to be opened.
A selection of programs that can open DXF files can be found below:
On Windows:
- Autodesk AutoCAD
- Smith MicroPoser
- IMSI TurboCAD Pro
- Adobe Acrobat and Adobe Illustrator
- IMSI DesignCAD
- CorelCAD
- blenders
On Linux:
- Adobe Acrobat
- CADEMIA
- LibreCAD
- blenders
- BRL CAD
- Wolfram Research Mathematica
- FreeCAD
On Mac:
- Adobe software
- Trimble SketchUp
- Cheetah3D
- Dassault Systemes SolidWorks eDrawings Viewer
- CorelCAD
- blenders
- Dassault Systems SolidWorks
For converting DXF files
The majority of programs that can open and edit DXF files also allow conversion. In addition to various online services, conversion is possible, for example, with the Adobe software suite, which is available on all common operating systems.
The Adobe suite also enables conversion to PDF format, for example. This can be useful when sharing content from the file type with people unfamiliar with CAD software. To do this, simply open Adobe Acrobat and the DXF file, then navigate to "Tools" and then to "Create PDF file". You save the converted file and can then send it.
Weaknesses and common problems when dealing with DXF files
First of all, you should know that the DXF file format is not completely exempt from disadvantages. For example, it is not able to take over CAD software-specific functions and thus make them available in another CAD software. It is also conceivable that the file format generally does not support some new functions and features from CAD programs.
In practice, one of the biggest shortcomings is missing dimensions within a DXF file . This is due to the fact that measurements have different notations around the world. For this reason, size relations are included in a DXF file. So the file tells you how big an object is compared to another object, but not the exact dimensions. These must be taken separately and typically entered manually. In technical jargon one therefore speaks of a "dimensionlessness" of the DXF file format.
In addition, DXF does not directly support different line widths and system fonts . These have to be exported and translated separately, which could lead to relatively complex import processes for the recipient of the file in subsequent file exchanges. Therefore, line weights are usually encoded as line colour.
3 common problems and their solutions
Problem #1 - too much information
Component and technical drawings contain dimensions, lines of symmetry, title blocks and the like - but cannot be processed for the reasons just mentioned.
Solution: Clean up the DXF file until only the component contour remains.
Problem #2 - Polylines
If contours are generated by a high number of short lines, loading times are long and cutting speeds are reduced.
Solution: Use predefined shapes such as circles or individual circle segments instead of polylines.
Problem #3 - Contours
Both overlapping and open contours can cause problems.
Solution: Completely remove the mentioned contour overlaps and open segments. If the contour is to be open, a line between the end points can be used.
