3.7 | 53 Votes
What is an IGS file?
An IGS file is a graphics file saved in a 2D/3D vector format based on the Initial Graphics Exchange Specification (IGES), a standard ASCII text-based format. It stores wireframe models, surface or solid object representations, circuit diagrams, and other objects. Many CAD applications save and export vector data as IGS files.
IGES is a standard for transferring three-dimensional models between CAD programs. You will most likely encounter an IGS file only if you work with CAD software in a field that involves manufacturing, such as the automotive or aerospace industries.
The Integrated Computer-Aided Manufacturing (ICAM) United States Air Force department developed the IGES format in 1980. Many CAD programs subsequently adopted it, and it became a standard. However, in the mid-1990s, the STEP (.STP) format replaced the IGES format, and the usage of IGS files eventually declined.
NOTE: IGS files may also be saved with the .iges file extension (.IGES files).
How to open an IGS file
You can open IGS files with various desktop CAD programs, such as Autodesk Fusion 360 (Windows), Dassault Systemes CATIA (multiplatform), Nemetschek VectorWorks (multiplatform), and CADEX CAD Exchanger (macOS). You can also open and view IGS files with online viewers by uploading them to CADEX CAD Exchanger Cloud or ShareCAD.org.
Since IGS files store plain text information, you can open them with a text editor (you may need to change the .igs file extension to .txt). However, when viewing the files with a text editor, the contents will appear as text instead of a visual representation of a model, like when you view them with CAD software. You can use text editors, such as Microsoft Wordpad (bundled with Windows) or Apple TextEdit (bundled with macOS), to view the plain text in IGS files.
How to convert an IGS file
Various CAD applications, including CADEX CAD Exchanger, Autodesk Fusion 360, and Dassault Systemes CATIA, can convert IGS files to other formats.
For example, CAD Exchanger can convert IGS files to the following formats:
Programs that open IGS files
Indigo Renderer Scene File
3.3 | 19 Votes
An IGS file may also be a 3D scene used by Glare Technologies Indigo Renderer and Indigo RT, applications for generating photorealistic images. It contains information about a scene in the XML standard, including the models, materials, meshes, and camera and rendering settings.
Glare Technologies Indigo Renderer and Renderer RT are cross-platform 3D rendering applications primarily used by professional artists to create photorealistic images. Indigo RT offers similar features as Indigo Render, but for a discounted price. Indigo Renderer is also available as a standalone application or as a plugin for other 3D CAD programs.
How to create an IGS file with Indigo Renderer
You can create an IGS file with Indigo Renderer when saving a scene. You may also export a scene as an IGS file from another 3D modeling package with the Indigo Renderer plugin, including Blender, 3ds Max, Cinema 4D, Maya, SketchUp, or Revit.
To create an IGS file with Indigo Renderer, select File → Save Scene or Save Scene As.
How to open an IGS file
Once you import an IGS 3D scene into Indigo Renderer, you can render it into a final image. The software supports GPU acceleration so that images can be generated more quickly.
Opening an IGS file with a text editor
Since IGS files are saved in plain text, you can also open them with a text editor, such as Microsoft Notepad (Windows) or Apple TextEdit (Mac), or a source code editor. You may need to rename the .igs file extension to .txt for the text editor to recognize it.
When opened in a text editor or source code editor, you can modify the properties of the IGS file. However, if you incorrectly edit the file, you may inadvertently corrupt the scene.