It’s customary now for most television shows to feature cinema-quality visual effects. But the effects work you see in TV shows like Game of Thrones, American Gods, and the soon-to-be-released Star Trek: Discovery owe a lot to the Trek series that ran between the 1980s and early 2000s.

It was in these Star Trek shows — The Next Generation, Deep Space Nine, Voyager, and Enterprise — that visual effects artists took a very cinematic approach to realizing spaceships, creatures, and alien worlds, using a variety of practical techniques such as models and miniatures that eventually evolved into the use of CGI and other digital tools.

Miniatures of course played a large part in the original 1960s Star Trek series and the early films; this continued in The Next Generation, which started in 1987. The miniatures, including the Enterprise-D, were built in intricate detail by experienced model makers. To get them onto the screen, they were filmed using a technique called motion control. This is where a camera filmed the model while hooked up to computer-controlled crane that moved in a preprogrammed fashion.

So why was motion control used on The Next Generation? Well, apart from this still being the early days of CGI, where digital models weren’t yet up to the task of looking photoreal enough, what motion control allows you to do is film a model against something, like a bluescreen, and then "composite" it against something else, such as a starfield.

It’s used for another reason too. If you have lights or engine exhaust or bright windows as part of the ship, these are things that cannot be filmed at the same time as the model, because you can’t get the proper exposure on all those elements together. But with motion control, you can film each of those things separately and combine them all later, since the camera moves can be repeated precisely.

“Motion control allows you time to get a proper exposure for every element,” Dan Curry, a visual effects supervisor who worked for several years on these seminal Star Trek series, told SYFY WIRE. “This includes getting what’s called a matte pass, which is where we obtain a perfect silhouette of the ship so that you can make a hole in the background and have a place to put the ship in it.”

Video of TNG VFX Motion Control

Motion control was crucial for spaceship shots in Star Trek, but it was also time-consuming, and not always possible under fast-paced television time and budget constraints. Curry says that meant that in his early days of working on the show, he’d have to find ways of telling the outer-space stories without the audience feeling cheated. "They were used to Star Wars by then," he notes. "And they expected that quality in visual effects."

"Early on in Trek," adds Curry, "our budgets were so low that sometimes when we'd have the guest alien of the week, I would make a model out of gluing a couple of toy submarine hulls onto a shampoo bottle and sticking a bunch of model parts on it, and that became the ship.”

Another time, Curry was called upon to build an escape pod. With little time or money, he visited a hardware store and found a piece of material usually used to repair sprinkler systems. “Once I stuck a couple of things on it and put a ping pong ball in a certain place, it looked like an escape pod. So for 25 bucks I had a model that, had we gone to a professional model builder, would have cost at least a couple thousand, which we didn't have in our budget.”

Several other old-school methods were also used regularly for the Star Trek TV series of the 1980s-2000s, such as cloud tanks with injected liquids used to represent alien atmospheres. “The trick with that,” says Curry, “was you would make different temperatures of water in these large aquariums, and then we’d inject paint or heavy cream for the clouds. As it hit the different layers of different temperature waters, it would behave differently, just like what would happen in the atmosphere.”

Models and practical effects remained part of the Star Trek VFX process for a long time, but the new digital technologies also meant new ways of creating ships, creatures, and enemies for the show. One of the first uses of CGI was for the episode "Datalore" in The Next Generation, in which the crew of the USS Enterprise-D encounters a crystal-like entity. “That was one of our first CGI things, because we couldn't really make anything physical like that,” says Curry.

The first CGI creature appeared in a 1991 episode of The Next Generation called "Galaxy’s Child," but it wasn’t until during Voyager (1995-2001) that the production felt CG spaceships were feasible. “We were a little wary of going with CG ships because the artifacts of the surfaces looked always a little sketchy,” recalls Curry. “We would use models for the foreground ships, but often the background ships were CG until we felt confident enough in the look of CG to use them for everything.”

Although Curry helped usher in the use of CGI in the Star Trek TV series, he says having worked in both eras of practical and digital effects helped him ensure that the newer approaches to VFX were still grounded in reality.

“When we filmed a ship's motion control, for example, you couldn’t really do impossible camera moves, because you had the physical limitations of the camera rig filming the model,” states Curry.

“I think those limitations were good. The audience knows when they see a camera flying all over the place that a real camera can’t do that, and it tends to be a subconscious thing -- it can take them out of the moment.”