“...responsible for operating, protecting, and maintaining the theatre’s technical assets, while also managing and overseeing the different technical departments, including set, lighting, costumes, props, sound, and effects.” -- Berklee
The Technical Director works with the set designer to create the set from the small model the set designer creates to a technical draft (sketch) used by carpenters.
They will collaborate with production manager, director, and designer on feasibility, cost, and equipment capabilities.
Another important aspect of being a technical director is ensuring that all technical aspects of a production runs smoothly. This vital part varies due to the production being performed. They also will run the crew who builds the set itself, following the measurements they've selected for each part
During the designing phase, set designers engage in a dynamic process, often creating multiple version of their designs and/or remeasuring things. They must refine their ideas based on feedback and evolving creative team discussions.
Once the design developes, Technical directors often move to digital drawings, which offer a more detailed and realistic visualization of the set. They have the option to create three-dimensional models that allow adjustments in perspective, lighting, and texture. This also opens up a door to find out the spots on the set where shadows will be noticed (which lighint designers benefit from this).