I did visual effects for 'Game of Thrones,' including the Battle of Winterfell scene with all the zombies. Here's what it was like working behind the scenes.

• Alon Zaslavsky, 46, was a senior character-effects technical director for "Game of Thrones."
• He loved the show so much, he quit his other job to work for the show under a creative house.

This as-told-to essay is based on a conversation with Alon Zaslavsky, a 46-year-old senior technical artist at Jam City from San Francisco who used to work in visual effects for "Game of Thrones." It has been edited for length and clarity.

Video games, comic books, and animation — I've always been into those things, but it wasn't until I was 22 and got into graphic design for $9 an hour working full time at a photo-development and business-card-design company that I realized I could make money doing something creative. After hearing an ad for SAE Expression College, an animation school, I decided to check it out.

I was sold the second I walked in. I graduated during the dot-com crash, but I eventually got my foot in the door somewhere and became a technical director.

I worked on the Emmy-award-winning special- and visual-effects team for two seasons of "Game of Thrones": The finale for season four and multiple episodes of the final season. In between seasons four and eight, I also worked at Disney Animation on "Moana" and at Dneg (formerly known as Double Negative), where I worked on "Miss Peregrine's Home for Peculiar Children," "Alpha," and the first "Wonder Woman" movie.

I joined the "Game of Thrones" team in 2014 while working with Scanline VFX. I quit working for Dneg to help with the eighth season full time, about eight to 10 hours a day. As a fan of the books, I didn't care what I was doing. I was just happy to be working on the show.

The episodes I contributed to for both seasons were the same episodes submitted for Emmys, and both times, those episodes won for outstanding special visual effects.

Visual effects take a long time to complete and a massive team to get the work done on time

Directly in my department, we had two to five people working on the clock, depending on the schedule. We worked on 2 1/2 minutes of scenes for the season-four finale, and just the visual effects for those scenes took four to six months to complete. The amount of detail that goes into this work is intense.

That's one of the reasons the visual effects on "Game of Thrones" were completed by multiple effects houses like the one I worked for. HBO would parcel out parts of episodes from each season to different effects houses, keeping the teams small because of budget constraints and high levels of secrecy. Keeping spoilers from reaching the public was a top priority (the nondisclosure agreements we had to sign were real). That meant the effects houses were working independently of each other, sometimes in silos.

We didn't know what other visual-effects companies were doing. We knew only what we had to do. We had our individual scenes, snippets, and parts to work on with specific characters and creatures without an understanding of the overall plot. On a daily basis, we would submit our work to our supervisor, and once the supervisor approved the work product, HBO would take a look and send notes back if they wanted further iterations.

There's a lot that goes into creating a creature or character for a TV show

For part of the Battle of Winterfell in season eight, I did all the zombies, or "wights." It was about 20 or so shots of wights swarming the dragon in that scene.

Creating a digital creature on-screen, like a zombie, starts with design. A 3D artist will take that design and sculpt it using 3D software, turning it into a three-dimensional statue. An artist will then give the statue textures.

The textures define how the character will look in the digital lights and how its final look will come out once it's rendered. That textured statue then goes to what's called a rigger.

Rigging is the technique used in animation to create a 3D character using interconnected digital bones. A rigger is someone who will put the digital bones into the 3D statue, work on the skin, make sure the statue is attached to the digital bones, and then give the bones animation controls — turning that statue into a digital puppet that an animator can manipulate and animate.

Then, the 3D animators will bring the character to life, using digital lighting to recreate the effects happening in the scene that the real-life camera picked up. That way, it all plays together as if it were happening in real time.

I was the senior character-effects technical director, meaning I directed the tools and software for what needed to be done. Often, I would set up the digital rigs for character movement. For the dragons on "Game of Thrones," I worked with my team to create a digital cloth rig for the wings so they'd move on-screen properly.

To keep continuity between episodes, sometimes we were given a model to work with from the original effects artist

The models were not complete works.

My team and I would have to rerig the character that we were recreating based on the model because the original effects house that built the character maintained proprietary rigs with trade secrets that it keeps for its internal team. That meant if I needed to work on a dragon that was originally created from another effects house, I'd be given the model of the dragon to work with but the model wouldn't have the infrastructure for animation. So my team and I would have to repaint, rerig, and retexture the dragon and get it as close as possible to the original.

Once the pieces from the individual effects houses were ready, they were sent to the main in-house visual-effects supervisor for "Game of Thrones," who then wove it all together to create the final episode that streamed on our screens.

A compositor would take the digital renders and lay them on top of the video that was captured on set, add all the visual effects (including other effects, like fires, smoke, or fog), and then composite everything together into one final image, blending all the layers to look like they belonged together.

This process was long and arduous, with many hands involved to get the final result

The biggest challenge was creating these types of scenes at companies that didn't have the necessary tools, so I had to create the tools we needed — which was nothing compared with what Thomas Schelesny, the visual-effects supervisor, did for me. He submitted my name for recognition with the Television Academy, so I received a personal-recognition award, which I framed. He did so for both Emmys, so I have two.

I loved working on a show I was so passionate about. The only thing I didn't like was that I didn't get to work on more of it.