.FCSTD

Introduction

FCStd is the document format of FreeCAD, the free and open source parametric CAD program. A document holds every object in the model with its properties: sketches and their constraints, the features built from them, spreadsheets that drive dimensions, and the resulting solid shapes, together with how each object is shown on screen.

Because FreeCAD is open source and the file is a ZIP package of readable parts, the format is fully open, although it is defined by FreeCAD’s code rather than a separate specification.

Structure

An FCStd file is a ZIP archive. Document.xml lists the objects, their types, properties and links to each other. GuiDocument.xml holds the display settings, such as colours, visibility and the camera. Shapes are stored as separate files in Open CASCADE’s BREP format (.brp), named from Document.xml, and a thumbnail is often included as thumbnails/Thumbnail.png.

Links