Anatomy Of An Explosion

Video games love a good explosion, but how are these spectacular effects designed?

- Rick Lane

Explosions are some of gaming’s most dazzling effects. Ever since Doom’s toxic barrels let players turn demons into soup, developers have striven to make explosions bigger, more spectacular, and more dynamic. Today, explosions appear in all sorts of forms for all sorts of purposes, whether it’s starting a revolution in Just Cause, or triggering a tactical chain reaction in Divinity: Original Sin.

In a matter of moments, explosions can change dramatically in size, shape, and color. They can be triggered by the player in all kinds of different ways, and radically alter the existing game state. But how do development studios actually tackle these stunning, violent and oh-so fleeting effects?

Chris Judkins is principle VFX artist on Just Cause 4, which aims to continue the series’ tradition of offering plentiful explosive potential. Judkins states that a good explosion starts with research. “Explosions act drastically different depending on what’s blowing up,” he says. “Fuel and gasoline produces dark, churning, slow-burning smoke that lingers for a long time, while propane burns fast, bright, and violently. Keeping these factors in mind and staying consistent throughout the game helps make the explosions feel grounded in the world.”

Regardless of what kind of explosions a VFX artist is designing, a successful combustion is always founded upon the engine’s particle system. “Particles determine not only the look of an explosion, but also details the movement,” Judkins continues. “Even in a realistic-looking game we make a lot of stylistic decisions to help the explosions have more impact and wow factor, just like in Hollywood movies.”