Fire in Video Games
I'm a firefighter now!
In January I became a proud member of the local volunteer fire company. I was told they need people over 21 years old to drive the fire engine. I really want to drive the fire engine. They don't let just anyone drive the fire engine, unfortunately, so first I need to take a course and qualify as an interior firefighter. This week the course focused on fire behavior. Being the nerd I am, I started thinking about fire portrayed in video games, and here I am to share my thoughts!
Before I get into video game specifics here is a few quick facts about fire behavior:
The stages of fire are ignition, growth, free burn, and decay.
The "fire tetrahedron" describes the conditions needed to have a fire. The sides of the tetrahedron are heat, oxygen, fuel, and the actual chemical reaction that releases heat and light. Without all four sides of the fire tetrahedron a fire can not sustain itself and will begin to decay and eventually (or quickly) extinguish.
Fire produces carbon dioxide, water vapor, carbon monoxide, light, heat, and lots of nasty other things you do not want to breathe that vary depending on the fuel (including various cyanides or acids).
When heated above its flashpoint, a flammable substance will start releasing flammable gasses. It is these gasses, not the solid or liquid fuel, that burn. The chemical decomposition that releases these gasses is called pyrolysis
Uncontrolled, growing fire doubles in size about every thirty seconds.
The life of a fire can be summarized thus: things get hot, fuel that is heated releases flammable gas, the gasses ignite and start to burn, the fire releases gross stuff you don't want to breathe, and eventually the fire runs out of the things it needs and it dies.
Now that we have that out of the way, how does the behavior of virtual fire compare to that of honest-to-goodness fire?
Often fire is used in video games as an excuse to implement some game mechanic that is needed. Candles in Skyrim never burn out; Fallout 3 is littered with "forever fires;" and in Bioshock you can ignite puddles of flammable gas, wait for them to extinguish, and reignite them as many times as you please. We can see in these games that fire is an excuse to have light in a dark passage, to have barriers to the player, and to have a novel environmental weapon to use against enemies. What bugs me the most is the forever fires. In Half-Life 2, for instance, there are static fires all over that just...burn. There's no smoke, no growth, no decay...just a fire that always has been and always shall be. Many games treat fire this way because it is easy. The way real fire behaves is not important as long as some kind of game mechanic is realized.
By contrast, Far Cry 3's fire mechanics strike me as novel. Fire is still used to implement various mechanics, but it is more realistically implemented. In scripted sequences of the game, such as escaping a burning building, the protagonist coughs as he makes his way through fire. Not near enough smoke is produced in these sequences, but the game really shines when you set some flora alight while free-roaming the island. This virtual fire is fairly realistic. In order to set a fire with a flamethrower, you need to actually concentrate on one spot for a bit of time to heat it up before it ignites. The fire spreads quickly and produces a good amount of smoke. Scenery is blackened to show that some damage was actually done. If you are not careful this fire can surround you and cause a big problem. It is perfect? No. Is it the standard that I now hold all virtual fire to? You betcha.
