The "extreme" act of rail grinding is represented quite well in video games, from Sonic Adventure
to Tony Hawk's Pro Skater
. But Square Enix did something unique in implementing foot-to-rail gameplay in its role-playing/fighting PSP game Dissidia Final Fantasy
A new Games Demystified feature on Gamasutra
from developer Jeremy Alessi analyzes the mechanic down to the code. Alessi writes: "Obviously, the rails in Dissidia Final Fantasy
are used for speed. Whether you need to escape a grueling attack or you just need to race across the map to collect an EX Core item, the rails are there to allow fast, accurate transport."
"The question, as always, of course, is how can we simulate this precise method of transport within the world of a video game? The answer is something called a spline path. There are numerous ways to create a spline path."
Alessi continues, "Following a spline path is a fairly trivial task algorithmically. The base concept consists of a series of nodes or points in 3D space. These points are then linked together sequentially so that an object may traverse them from point A to point B."
"Of course, a character or object must be able to follow the path even if the total structure of the linkage isn't linear, like the curvy light rails in Dissidia
," he adds. "The motion of the character along the light rails is smooth because there are many nodes within the spline path."
Alessi says that although grinding on a rail is about as linear as a gameplay element can get, there are a few ways to create a spline path. In the full feature, he provides screens from 3DS Max, and accompanying instructions and code for creating grind-able rails.
For a more in-depth look at spline paths and rail-grinding in Dissidia Final Fantasy
, read the full Gamasutra feature
, available today.