Inspiration, Pro Tips

Crowd Control: VFX Techniques for Digitally Duplicating People


Audra Coulombe is the Marketing Manager for The Molecule, a VFX, Motion Graphics, and VR company located in New York and Los Angeles.

If you look out over the VFX department at The Molecule, you’ll see rows of artists working on computers and collaborating with each other. But what if we wanted to make it look like there were even more artists there? One of the effects we commonly address is called Crowd Duplication — it’s how we digitally fill stadium seats, streets, and theaters with people when the footage begins with a handful of extras.

In the earliest days of filmmaking, the view of a VFX department would reveal only the camera operator and director. At that time, most experimentation with VFX occurred in-camera during the shoot. Film legends like George Méliès and Buster Keaton were early pioneers of this process. They were among the first to experiment with in-camera illusions, and they figured out how to duplicate the human body by re-winding the film and exposing a different portion of it every time.

Back when cameras were cranked by hand, it’s a wonder they didn’t completely scrap the idea. One wrong move and the entire film stock would be ruined, and they’d have to start over. Today, duplicating people in post-production is much more forgiving. Experimentation happens quickly; we can try out new ideas, undo them if they don’t look right, and try them again.

There are a few methods VFX studios use to create seamless Crowd Duplication effects, and per usual, all methods typically belong to one of two categories: 2D and 3D.

The Epic Battle Scene: Crowd Duplication in 3D

Any Game of Thrones or Lord of the Rings fan has witnessed the 3D method of crowd generation — it’s what makes those battle scenes so epic! A production team can generate enormous armies without hiring and choreographing thousands of extras.

There are some great programs out there for this, the most popular being Golaem and Massive. Golaem is a plugin for Maya, so for 3D artists who are already familiar with the program, Golaem could be an easy-to-learn solution.

Golaem generates a lot of CG figures, but lacks the situational awareness and responsiveness of Massive-generated figures. Therefore, it works great if you’re creating a crowd heading in the same general direction and moving in a similar way, like these zombies by Stargate Studios in The Walking Dead:

If you need your crowd to be more interactive and lifelike, Massive is the industry standard for crowd creation. It has more artificial intelligence than Golaem, so you can “teach” figures to react in different ways to certain actions. When you need large crowds of individuals to fight with each other, this software is the best solution, as you can see in the “Battle of the Bastards” in Game of Thrones:

The Everyday Audience: Filling the Seats with 2D Crowds

A lot of the crowds that you see in TV and film are 2D composites made by artists. It would be expensive and time-consuming to hire an entire theater or stadium of extras for your handful of audience cutaways, so VFX offers an easy solution. If you rearrange a small group of actors in different configurations in each section set of seats, a VFX artist can stitch those takes together in post.

Four of the many pieces of footage used to create a full-crowd composite (from NBC’s “Smash”)

Smash full crowd theater
The final composite

Alternative Methods

Before you begin filming any scene with a crowd, it’s important to consider what the crowd will be doing. If your goal is to create a large-scale Roman battle scene, you would do well to scout for companies that have extensive experience with Massive. If the crowd is sitting still, you’ll save time and money by going with a 2D solution to fill in the empty seats.

Sometimes the solution doesn’t involve VFX at all. If your crowd is out of focus and the action is taking place in the foreground, you could always opt to fill the seats with inflatable people. They sit where you want them to, you don’t have to feed them, and you could always mix in some real humans to give the crowd a little bit of motion.

You could also get creative while filming in your community. Inviting friends, neighbors, coworkers, or your entire dorm floor to volunteer to fill in some seats is a great opportunity to help bring a community closer together.

For more about the history of Crowd Duplication, including examples from famous films, check out The Molecule’s blog.