The geometry can be defined very easily. Each border contour can be described by a starting point (e.g. the corner) and the method to reach the next point. This may be a straight or a curved line.

After setting all contour lines of the system, the program only needs the (preset) element size for building the mesh. There will be no other relation to the method of finite elements. No further settings are needed.

Depending upon this mesh size the mesh generation (together with later settings) is done automatically.
With this method, any system including holes of any shape or cut-off's can be built
and also very complex structures like such a framework.

For more information on how to build such meshes see here ...