He invented some technologies that were a subset of 3D printing. Infact DDD technologies even have limited upside because they are focused on the fabrication of macroscopic scale parts. Sterolithography can also be done on the nanoscale, and some argue is the future. For example, you can create nanoscale 3D parts using a focused ion beam. People have printed tiny nanoscale porche toy cars with it. DDD technologies are for macroscale devices and size features. Doesnt even cover the micro or nanoscale where most of the disruptive technologies will be introduced in the future.