Generalized cylinders

Example of a (generalized) cylinder which is not right circular

The video below shows the construction of a generalized cylinder in space from a planar profile curve (red) and a specification of the direction of rulings (blue). The cylinder consists of all lines passing through the profile curve which are parallel to the specified direction. Such lines are called the rulings of the generalized cylinder. In the video the rulings are cropped for better visibility.