FreeCAD: Using geometry constraints for 2D CAD
A great companion to Blender for any architectural visualization artist using only open source software is an open source CAD tool. From all the available options, FreeCAD is one of my favorite choices in this area due to the already great number of features, and the active development. In fact, we have some great new tools in development right now for FreeCAD. One of the new features on development is called Sketcher, which will add constraint-solver capabilities to FreeCAD. This means that we will be able to draw with geometry-constrained 2D shapes. This is a great tool to use if you want to speed up your drawing workflow.
Below, we can see two quick demo videos of the Sketcher feature, showing some of the geometry-based constraints.