How FreeCAD Creates 2D Drawings from 3D Models — TechDraw's Open-Source Projection Pipeline vs SolidWorks
You click “Insert View” in FreeCAD’s TechDraw workbench, point it at a 3D part, and a few seconds later a clean 2D projection appears on the drawing page. Hidden lines are dashed, silhouettes follow curved surfaces, and section views show cross-hatched cut faces. It looks like the same thing SolidWorks does. And at a high level, it is — both systems solve the same fundamental problem: project a 3D solid onto a 2D plane, figure out which edges are visible, and draw the result. ...