In construction and home building, feet and inches (at least in the US) aren't typically used -- instead, just inches are used. Most blueprints simply have inches, then halves, quarters, eighths, or ...
Manipulation of deformable objects has given rise to an important set of open problems in the field of robotics. Application areas include robotic surgery, household robotics, manufacturing, logistics ...
Empty drawing on DXF load. I had same problem with 2.1.3, so i updated, but same issue with last version. When I open librecad and use open in the menu, i have an empty drawing. (autozoom tried ;) ).