Lava in movies: how it's done?
- Alex Iwanoff
- Jun 4
- 4 min read
Molten rock. Ultra hot. Bright orange.
Lava is not an easy element to film or recreate—even with CG. That’s why filmmakers have had to be resourceful and use every trick in the book to depict how lava looks, moves, and destroys. Here's how three very different films tackled one of cinema’s most explosive challenges.
VOLCANO (1997)
In Mick Jackson’s Volcano, lava erupts from the La Brea Tar Pits and turns Los Angeles into a disaster zone. But as the director put it, “you can’t send out for a truckload of lava”. So, the team built a “lava kitchen”, where they brewed their own.
What you see on screen is made from thickened methylcellulose (a food additive), dyed orange, lit with UV lights and filmed over miniature sets mounted on gimbals to control the flow. The result was a convincing molten effect, composited with live-action plates and digitally enhanced to look hotter and more dangerous.
“Once you’ve established the data of the plate that the lava is to be composited into, we scale everything down to 1/8 version of what it was, and we built shapes of clear plastic to put in place where there are objects in the frame, and it gives a very realistic look as [the lava] is deflected and bent around these shapes”, David Drzewiecki, Miniature FX supervisor DP
Given the complexity of the destruction sequences—which included fast-moving lava, balls of lava, ash, flames and explosions—the team went through an extensive research phase, combining practical experimentation with CG simulations to get the several layers of natural phenomena and destruction just right. This included creating a massive set and using 20.000 gallons of propane and hundreds of pounds of black powder.
“In its most basic form, compositing is taking two layers and integrating them into a finished one. A pretty typical shot in Volcano for us has been using 20 or 30 layers to generate a finished shot”, Greg Strause, Digital Artist, Light Matters, Inc.
STAR WARS: REVENGE OF THE SITH (2005)
We cannot talk about lava in movies without mentioning the fiery duel between Anakin and Obi-Wan on the volcanic planet Mustafar. And naturally, it had to be a spectacle.
“The big challenge in Mustafar is lava. And there’s lots of it—and lots of different scales”, John Knoll, VFX supervisor at ILM.
To pull it off, the team used everything in their arsenal: matte paintings of digital environments, CG simulations, real footage from a Mount Etna eruption happening during production, motion-control cameras, large-scale miniatures... you name it.
Part of the Mustafar landscape was built as a physical model, tilted 10 degrees to allow controlled lava flow across its surface. That lava? Once again, methylcellulose—the same food additive used in Volcano—was dyed but, this time, it was lit from underneath to simulate the glowing magma. The crust was created using ground cork.
“Digital technology has completely revolutionized the visual effects industry. But sometimes, nothing beats the old-fashioned use of models and miniatures. And we don’t always look to the future, we often look back”, Rick McCallum, producer.
What you can’t overlook in a sequence like Mustafar is the sound. You simply can’t talk about visual effects without it. It’s essential to selling the illusion.
To create the bubbling, erupting feel of the lava flowing, bursting and hissing, sound designer Ben Burtt blended artillery mortar blasts with recordings of liquid textures to capture the explosive, fluid energy of molten rock. “You blend the two together, and have a new effect”, he explained in Star Wars: Within a Minute – The Making of Episode III.
FIRST DEPICTIONS OF LAVA IN MOVIES
The Last Days of Pompeii (1935) appears to be the first film to attempt a realistic depiction of lava on screen. You have to wait until the climax for Mount Vesuvius to finally erupt, but when it does, the destruction is full of fire, collapsing sets and... some shots here and there of flowy lava.
This was decades before CGI, so everything had to be done practically (no computers, all real, in camera... you know, like today’s Oppenheimer or Romulus, cough cough).
Under the supervision of special effects pioneer Willis O'Brien (who had just revolutionized stop-motion in King Kong, 1933), the team used miniatures, matte paintings on glass, and early compositing techniques like split screens and a primitive version of blue screen.
As for how they created the lava itself—well, that's less clear. No confirmed records seem to exist. But for One Million Years B.C. (1966), it’s documented that they used a mix of wallpaper paste, oatmeal, dry ice and red dye, according to Kinorium. In the 1935 version... well, it was in black and white. So the glowing orange was one less problem to worry about.
Comentários