IGS to TXT Converter

IGS to TXT Conversion Explained

Converting .IGS (Initial Graphics Exchange Specification) to .TXT (Plain Text) changes a 3D CAD model into a standard text document. Because .IGS files are already written in ASCII text using a strict 80-character line structure, you can technically open them in any text editor. However, a true conversion to .TXT usually involves extracting specific geometric data—such as XYZ point coordinates or file metadata—into a clean, human-readable format.

When you convert .IGS to .TXT, you gain universal readability and the ability to process coordinate data using custom scripts or spreadsheet software. You lose all 3D visual representation, NURBS surface definitions, solid topology, and assembly structures. If your goal is to view or edit a 3D model, this conversion is a bad idea. You should use .STEP or .STL instead.

Typical Tasks and Users

This conversion is highly specialized. It is rarely used by standard designers, but it is critical for specific technical workflows:

• Metrology Engineers: Extracting 3D point clouds or boundary coordinates from an .IGS file to program Coordinate Measuring Machines (CMM).
• Data Scientists: Pulling raw geometric data into Python or R scripts for mathematical analysis without needing a CAD software API.
• CAD Administrators: Reading the "Start" and "Global" sections of an .IGS file to audit which software generated the file, the author's name, and the units of measurement.
• CNC Programmers: Extracting specific toolpath coordinates or drill hole locations into a plain text format for legacy manufacturing equipment.

Software & Tool Support

You can open, edit, and convert these formats using a mix of CAD programs, text editors, and programming libraries:

• CAD Software: Programs like AutoCAD, Rhino, and FreeCAD can import .IGS files and export specific point data to .TXT or .CSV.
• Text Editors: Tools like Notepad++ or Visual Studio Code can open raw .IGS files directly to view the ASCII code.
• Programming Libraries: Python libraries such as pyiges are used to parse the complex IGES structure and output clean .TXT data.

Pros and Cons of the Conversion

Pros:

• Universal Compatibility: Every operating system and device can open a .TXT file instantly.
• Data Accessibility: Extracts locked coordinate data for use in databases, spreadsheets, or custom software.
• File Size: Extracting only the necessary points or metadata often results in a much smaller file than the original 3D model.

Cons:

• Total Visual Loss: The .TXT file cannot be opened as a 3D model. All visual geometry is destroyed.
• One-Way Process: You cannot easily convert a .TXT file back into a working .IGS CAD model.
• Complex Parsing: Raw .IGS files use an outdated Hollerith string format from the punch-card era. Extracting meaningful data requires complex mathematical evaluation.

Conversion Difficulties & Why Convert.Guru

The main technical difficulty in converting .IGS to .TXT is the internal structure of the IGES format. An .IGS file is divided into five sections: Start, Global, Directory Entry, Parameter Data, and Terminate. The geometry is defined mathematically in the Parameter Data section using pointers that reference the Directory Entry section. Extracting a simple list of XYZ coordinates requires a parser that can read these pointers, evaluate the mathematical curves (like B-splines), and translate them into raw text points.

Convert.Guru handles this complex parsing automatically. Instead of forcing you to write custom Python scripts or buy expensive CAD licenses to export point data, Convert.Guru reads the IGES directory structure, evaluates the geometry, and extracts the relevant data into a clean, structured .TXT file. It manages the legacy 80-column formatting so you do not have to.

IGS vs. TXT: What is the better choice?

Which format should you choose?

Choose .IGS if you need to share a 3D model between different engineering teams, import a part into a CAM system for machining, or archive legacy CAD data.

Choose .TXT only if you need to extract raw XYZ coordinates, feed geometric data into a custom script, or read the file's metadata. If you want to share a 3D model but your client cannot open .IGS, do not use .TXT. Convert the file to a modern 3D format like .STEP or a mesh format like .STL.

Conclusion

Converting .IGS to .TXT is a specialized data extraction process, not a visual conversion. It makes sense when you need to pull raw coordinates or metadata out of a legacy CAD file for analysis, scripting, or metrology. The biggest limitation is the complete destruction of the 3D model; the resulting text file cannot be viewed as a 3D object. Convert.Guru provides a reliable, accurate tool for this exact workflow, bypassing the need for complex CAD software and delivering clean text data instantly.