My first programming job in 1972 put me in an experimental auto industry group using 64K Control Data computers hooked up to Lundy crts to turn assembly plant blueprints into a multilayered CAD database. Assembler was used for the time-sensitive stuff and Fortran for the rest.
We chose an accuracy size of 1.5 inches (1/8) foot and, until a decent floating-point processor came a few years later, did all scaling in powers of 2. This allowed for scaling using fast bit shifts. Standard objects like conveyors were shown as variable length symbols, stored as an integer number and integer XY location.
We had 256 layers, allowing the separation of conveyors from electrical and plumbing. We spent days squeezing bits and microseconds. In the end, it was an impressive, fast system.
We then added some 3D capabilities using matrix algebra for rotations in 3 dimensions. Alpha strings were coded as hexadecimal values, and I would dream in hexadecimal. It was a great job. I often regret leaving.