The VFX of Ghostbusters
Linda Romanello
September 6, 2016

The VFX of Ghostbusters

It’s been more than 30 years since Hollywood has proven it ain’t afraid of no ghosts. It was 1984 when director Ivan Reitman introduced audiences to the now iconic, beloved supernatural comedy Ghostbusters, starring Bill Murray, Dan Aykroyd, Harold Ramis and Ernie Hudson. The movie was a huge box-office success, and went on to become a pop-culture staple. Now, in 2016, director Paul Feig ( Spy, Bridesmaids, The Heat) doesn’t shy away from bringing back the familiar storyline, along with the Ecto-1, Proton Packs and Slimer with four, new leading ladies and a host of new ghosts in his 2016 release, Ghostbusters, for Sony Pictures. 

According to Peter G. Travers, VFX super on the film, the movie-making technology has certainly advanced since 1984, and the days of puppets and optical composite-ghosts. “Back then, you could not make digital ghosts. The digital technology has opened up the possibilities for everything. And every shot in the film is essentially a digital effect because we had digital intermediates, it was all shot on digital cameras and we color timed everything digitally.”

The film was shot on-location throughout Massachusetts on Arri Alexa XT cameras in Arri raw format, cut on Avid and the visual effects were completed by a long list of VFX houses, including Sony Pictures Imageworks, Legend 3D, Iloura, MPC and Zero VFX. 

Here, in an exclusive interview, Travers and Sony Pictures Imageworks’ (SPI) VFX super Daniel Kramer discuss the 1,700 visual effects shots and what it took to bring the film's ghosts to life. 

Can you discuss the effects in this film? 

Travers: “I started on this film in February 2015 and one of the most important things was to figure out what kinds of scenes and effects [director Paul Feig] wanted for the ghosts. I asked him, ‘Do the ghosts glow?’ And he said, ‘Yes.’ That really sent us down this path of what to do, how to do it, how to shoot it and how to do things in post. Often times, when effects don’t work in movies, it’s because they don’t have a supportive relationship with what is shot and so every time you have an actor trying to act against a tennis ball or you light a scene not knowing what kind of lighting you’re ultimately going to do in post, or when you try to marry the two together, they don’t marry. You can’t really force it. You have to do a lot on the front end to figure out how you’re going to do all this.

“A lot of times in movies, we try to introduce effects that weren’t really there on-set, right? We try to figure out a way to practically have some kind of lighting effect on-set that can just go right in the film or be manipulated in some way, rather than try to cheat lighting into photography when it’s not there, which is very difficult. We do it a lot, but it’s never going to look as good as if you can actually get the real effects lighting in there. So the trick is, how to create effects lighting in a shot on-set.

“There are a bunch of different effects — the proton beings, the ghosts themselves, and we have any kind of environmental lighting that we had to put in, like if they’re in [New York’s] Times Square. We couldn’t shoot in Times Square and, for the most part, we couldn’t shoot in New York. So almost all of the Times Square set is digital, except for the ground and a few store fronts. So, as far as preproduction getting all of that ready to go, we bought a ton of LEDs. How the LEDs fit is, based on what I learned from working on Watchmen [with Dan Kramer] and working on Dr. Manhattan in that film, we sewed in something like 2,500 LEDs into this costume that Billy Crudup wore. We got all this interactive light and that was a real learning lesson for me. As we were watching dailies on that movie, we noticed that light would bleed off these LEDs and kept casting shadows in areas that we could have only guessed at what it was doing and never would have exactly matched it. And in some ways, it did things that we weren’t expecting, but it always looked right, it always looked interesting and it always looked compelling. So, we thought, let’s do that for the ghosts in this movie.

“What was really interesting about Ghostbusters was that really early on, when figuring all of this out, we wanted to be able to have these LEDs incorporated in at a costume level where some of these ghosts, like Gertrude for example, actually had the LEDs sewn into the costume. So a good portion of what you see in Ghostbusters for the first ghost in the haunted mansion, is actual photography. And most people think, ‘Oh, it’s a CG ghost’ and you always think, ‘Is this practical or is it CG?’ And everything nowadays is a blend.

“The line is so blurred that you have no idea. What we had on-set was, an actress performing with LEDs in the costume that would create a glow on the environment and that glow went directly into the movie. We had an awesome eyeline for the Ghostbusters girls, they knew exactly where to look. They had a glowing, hovering lady in front of them.

“Rather than spending tons and tons of money in post, and we do spend a lot of money in post, this gives us a leg up so to speak, so we don’t have to add lighting in to the environment, it’s all there. So that scene [with Gertrude], when you look at it, and it feels right when she reveals herself to the girls. When you look around the rest of the scene, the frame, you see all these light kicks and reflections. It’s all what we shot. It’s probably one of the most practical, glowing ghosts you’ll ever see on film.

“For the final scene in Times Square, that we actually shot in Weymouth [Massachusetts] at a decommissioned naval air station, we built a section of Times Square there. Just the footprint. The ground was photograph-ready. We got these cargo containers. It was about a quarter to a half-mile of greenscreen surrounding the whole thing and we replaced the storefronts and the skyscrapers around it. That’s what Dan’s team had the challenge of doing.”

Dan, can you tell us more about the Times Square sequence?

Kramer: “Imageworks did around 300 shots in the film and one of the tasks was to build a fully digital Times Square — in two different time periods — for a scene at the end of the film. We had to build modern Times Square and then a 1970s version. The idea was, that the girls go into the ghost fight, with all these ghosts from the past coming forth and fighting the ghostbusters, and during that fight, not just the ghosts are coming from that past, but actually Times Square itself transforms into a Times Square of old. So, you’ll see the old buildings, like a Nathan’s hot dogs and all the things that were in Times Square at the time. It was quite a task, and we had to share that asset with MPC. Dave Seager at MPC headed up that group. We had a good collaboration where MPC would build certain buildings that were key for them and we would build certain buildings that were key for us and there was overlap there, but our action took place in slightly different areas of Times Square, and as a result we were able to kind of build the assets at high res for our own personal needs and then share with the other vendor to create a complete Times Square.

“In talking about this ghost fight, that was shot on a stage and so we ended up replacing everything, even the ground they were standing on, to make it look like aged asphalt and then the entire background was all replaced. Pretty much everything was CG, except for the actual ghostbusters themselves, and then some of the ghosts that come out are actors that were augmented to look like ghosts. Heavily augmented. Augmented so many times you should just say replaced (laughs).”

What was the biggest challenge of doing the VFX for this film?

Travers: “There are challenges everywhere. You always look at a film in the beginning and you have your educated guesses where the challenges would be. Inevitably, in every movie, there’s always an area that’s surprising how hard it is and also there are areas you know that as long as you prep them, they’re going to work.

“My personal favorite in the movie is the parade balloon sequence. Because getting back to what we were talking about earlier, we needed to find a way to light the environment — that gets a little challenging when these glowing parade balloons are three stories high and floating through the streets of NY. The parade balloons were actually shot with balloons that we floated in the scene that were lit from the interior. Otherwise, it would have been very difficult to light the environment. It was actually shot in downtown Boston in the middle of the night and we’re running around with these giant glowing balloons and driving them around on these carts. It was a wild experience, but what was most important about it was that everybody on-set was able to see where it was going. If we’re trying to do some elaborate effect on-set and everybody’s coming to me to ask, ‘How does this work?’ ‘What’s going on?’ and they’re all confused, odds are, you’re going to lose and it’s never going to look right. There were still questions to be answered, but when we had physical balloons that were paraded through the street, we had the palette to work with. You’re always trying to guess what reflections would do, what lighting would do, but with this, it gave us a starting point. The balloons we had on-set versus the balloons we eventually built digitally are very different from each other. But what’s really neat about the parade is that Dan’s team really ran with it as far as the simulations of the balloons and the effects that went on.”

Kramer: “I think one of the fun parts about it was, that we made these creepy looking balloons that were inspired by these old-time Macy’s Day Parades. We found lots of reference footage — black and white photography from the 1930s. A lot of it is black and white, so you can’t tell color, but if you look up the actual balloons themselves, they’re super creepy. So we didn’t change them that much.”

Travers: “No, not at all. We needed some kind of giant monsters in New York, and they needed to be ghosts, so they needed to exist in New York. I was like, ‘What kind of giant monsters can we come up with?’ And we thought, ‘Oh, wait, the Macy’s parade has these things floating around’ and  ‘What did they look like back in the day?’ I don’t think we could have designed them any creepier.”

Kramer: “Paul did want to add a lot of color to it. Even though we didn’t have a lot of color reference, we kind of embellished and gave a lot of primary colors to them to keep within the theme of the rest of the film. We used primarily Houdini to do the simulations and nCloth. Our lead effects artist, Pav Grochola, figured out how to do the finite elements simulations, which actually ripped the balloons apart which was cool and effective and, it’s just one of those things where just a few years ago, we wouldn’t have been able to do that. The simulation software, especially Houdini, has advanced so far that it’s one of those things that the timing was just right for us to be able to do it.”

What were some of the other key tools used?

Kramer: “We animate in Maya, use Massive for crowds and Houdini for all proton beams and particle effects. Compositing was all Nuke, for rendering we used Arnold. We have our own in-house version of Arnold. I can’t speak for the other houses.

“A huge theme throughout the film is, Pete and Paul wanted what they were calling 'emanations.' You can see it on Gertrude at the beginning of the film and on just about every ghost. They’re emanating this sort of particulate light, almost bioluminescence material effect. Even Slimer is emitting that material. So, that was something that was pretty intensive because we would have to pump millions of particles into every single character to achieve that look. But it created this interesting, bioluminescent look — a little bit of a fluid/smoke look around them that hopefully made them appear more ethereal.”

How was it working with all the VFX houses?

Travers: “Part of my job is the sharing of looks and you don’t want to have too many vendors on a movie, especially if you have an effect that carries on throughout the movie. Then everybody has to actually build that effect. We kept it to the right amount of vendors. We had to share some ghosts, which were developed at SPI, but the proton beams were what we had to share the most because they’re in every scene, so every vendor had to pick it up.

“Iloura did the rock concert scene that started out with the mannequin, which SPI did, but then the rock concert — Ozzyfest — features this big, weird demon which just shows up and it starts flying around. And it goes back to what we were talking about earlier, about how to light the set. Probably one of the more unique things we did in this film, in needing a way to light the scene with the flying ghost, was to cover a drone with LEDs and fly it around. One of the great things about that was, you get the interactive lighting. And, it was cool because we had hundreds of extras, and if the ghost was flying around, you need to get a certain kind of choreography, you need to get like 200 people all looking in the right direction. The drone was perfect for that because everybody knew where that ghost was.” 

Did you feel pressure to outdo the effects from the 1984 film?

Travers: “No, there was no pressure at all (laughs). Of course, it’s an iconic film! In some ways, you lose sight of the appreciation because you’re dealing with the day to day, but then there are moments when you’re like, ‘We can’t screw this up!’”