Abstract: Computer aided design(CAD) methods and systems of routing pipes, ducts and other services, such as utility and HVAC(Heating Ventilation and Cooling) lines in three dimensions(3D) through congested areas in industrial plants, ships, land vehicles, air vehicles, structures, buildings, and the like. The invention combines high speed real-time two dimensional router software and a simple graphical user interface to create an environment in which a designer can rapidly create fully valid 3D(three dimensional) routes for piping, HVAC(Heating, Ventilation and Air Conditioning) ducting, cableways and other swept shapes. The designer can use the invention to generate optimal 3D routes nearly as fast as the designer can move his/her mouse, and the invention can be imbedded within existing 3D(three dimensional) CAD(computer aided design) systems.