The Technology Behind Lifelike Fire in Video Games

If you boot up an old copy of a video game with an emphasis on explosions like the original Doom, some of the graphics may seem downright laughable. Shoot a rocket and a small cloud of red pixels floats up and then down. Play a game like the modern Call of Duty series, on the other hand, and you can launch an incendiary grenade at an oil drum to create a firestorm that looks just like the near thing. How do video game companies create the technology of fiery explosions?

In the Beginning

The first video games to feature any type of explosions were titles like Space Invaders, where the enemies died in a pop of white pixels. Any explosions were simply red and orange and yellow patterns that expanded and collapsed. Later titles like Afterburner had hand-drawn explosions that burst in every direction, rendered into 8-bit graphics.

As 8-bit graphics gave way to the 16-bit graphics of a Super Nintendo, explosions and fire could be rounded out and smoothed in order to create a true circle rather than a pudgy mess, but games continued to use the same template for explosions. A title like X-Wing, for instance, re-produced a small explosion when you shot missiles and amplified it to a larger explosion when you destroyed a Death Star. This would be typical throughout the sixty-four-bit era, as all fire programs were the same flickering mass without any originality.

To Make Fire

One of the big developments that led to lifelike fire was a program called Sprite. This allowed two-dimensional images to be integrated into the larger scene, blending together a new animation with the background. Adventure titles like Diablo used this to create the graphics of fire as the adventurer combated the (often-fiery) foes of Hell itself. This, however, was still fire in two dimensions, and fire that had no intelligence behind its programing. It could only flutter according to its commands, not on cue.

Making Particles Into Explosions

Modern rendering uses particle-based explosions for fire. A particle explosion uses an emitter to determine where the fire will travel if it is supposed to move. A rocket launched at a ceiling, for instance, will drop fiery debris, while a rocket launched at a floor will project hot chunks into the air. Explosions are difficult to render, even with particle programming, because they must come on the screen instantly yet have different dimensions of size, lifespan, brightness, and color.

In A 3D World

Basic sprites and even particles cannot make all three-dimensional fires look real, however. With modern game engines, all explosions must be created using different light rendering illusions. One creates the textures, so that a fire is bright in a dark room, while the other causes the flame to move, cast out sparks, and create smoke. A final rendering causes flames to interact with their environment, casting shadows and revealing hidden objects in the darkness. Gravity engines in the game add their own programming, as sparks or debris that is thrown up with either float gently down or quickly collapse according to the item’s size.

For the Best Titles

Triple-A video game designers with millions of dollars of budgets will incorporate other elements into the physics of a game. The body dynamics of the world of a video game dictates the reaction of materials to fire and explosions. If you launch a rocket into the side of a building, its dynamics dictate it to be hard, so that little structural damage is shown. A rocket launched at a teddy bear, by comparison, will either incinerate it or send it blasting miles away.

Author Bio: William Stevens is a writer who creates informative articles in relation to technology. In this article, he describes the technologies behind creating digital fire and explosions and aims to encourage further study with a bachelors in fire science online.