When NASA teamed up with Japan's Ministry of Economy, Trade and Industry in 2009 to release a detailed topographic model of the Earth's surface, the groups probably didn't envision their data being used to help design levels for a snowboarding game. But that's just what happened in the development of EA Sports' SSX, which comes out today with mountain courses built on top of that public domain data set. In other words, your tax dollars helped fund part of the level design for a mass-market video game.

"Name any mountain on Earth"

EA Sports producer and creative director Todd Batty still remembers the first time one of his creative directors pulled him into the office to show him just how easily the ASTER topography data (named after the Advanced Spaceborne Thermal Emission and Reflection Radiometer that collected it) could be used to make playable, virtual mountains.

"He was like 'Name any mountain on Earth,' and I was like, 'I don't know, Mount Everest.' So he goes on Wikipedia, gets the latitude and longitude coordinates... and in about 28 seconds, delivered a 3D model of Mount Everest and all the surrounding mountains in that grid from the data. He's like, 'If you give me a couple of days we can take it for a ride...'"

It was a revelation for a team that, up to that point, had been struggling to use procedurally generated 3D noise fields to partially automate the process of creating convincing-looking mountains, with largely unsatisfying results. "We were doing a lot of research of real-life mountains and the mountains themselves we were generating just didn't have any of the kind of personality and unique features of some of the craziest mountains we were seeing that actually exist in the world," Batty told Ars.

But with the ASTER data providing a free, complete, easy-to-convert map of the best snowboarding runs nature had to offer, all that work seemed beside the point. "We thought, 'Wow, are we done?'" Batty recalls.

Cleaning up reality

Actually, no, they weren't done. While Batty said the ASTER data gave them a "huge head start" by providing the basis for the in-game mountains, the resolution was low enough that it needed a bit of touching up to look good up close. The developers also needed to add details like trees and rocks that were not captured in the ASTER data, and carve out the series' signature jumps and grind paths to make the runs more fun.

"We wanted to include most of the big iconic mountains in the world, [but] for some of them we'd say 'No, it's too jaggy, there's just no really good nice valley to ride," Batty said. "There were some [mountains] where we basically had to take in a virtual bulldozer and completely obliterate a lot of what we found to create the basis for the course we would eventually build on there... There were a few places in Patagonia that were just too damn steep, with 80 degree faces that would just get you going at the most ridiculous speeds in our game."

Funnily enough, Batty said, the natural world has created snowboarding paths that are far more ridiculous than even the insanely over-the-top courses the SSX series is known for. "Every time we thought we were pushing the boundaries too far, somebody on our team would send out some picture of somewhere in the world that was more ridiculous. We'd put [these real mountains] in the game and people are like 'That's the craziest thing I've ever seen, it's so over the top' and I'm chuckling inside because I can show you a picture of where that actually exists somewhere in the world."

But it was the unnatural bits in the data that inspired some of the game's most interesting diversions from reality, Batty said. "When there were really minor errors or holes in the data, we would be riding and taking a look at one of the raw data bits, and then there'd be this giant gaping hole that we'd fall into," Batty recalls. "And we were like 'Hey, that's pretty cool, why don't we build out an underground cavern in there.'"

Nature versus technology

More than just creating cool course ideas, though, the natural world captured in the ASTER data also just feels more... well, natural than anything the team could create purely through programming. "The data we get back holds pretty true for the major ridge lines, the valleys, the way the waterline over years has eroded and kind of flows down that gives these amazing natural built-in tracks that move and flow super organically down the mountain," Batty said. "When you try to do that through algorithms and a computer is just comes out feeling much more mechanical."

So, basically, the team behind SSX substituted millions of years of erosion and tectonic shifts for months of painstaking programming and design. "Nature, over thousands of years, does some incredible, crazy things to terrain," Batty said. "If we were doing it by hand we'd be trying to experiment and recreate stuff that, in nature, is found all over the place."

Could other video games save time and effort by virtualizing real-world locales, rather than trying to create artificial environments from scratch? Batty said he could definitely see racing games or flying games taking advantage of the ASTER data set to create authentic cross-country courses. "There is also something called LIDAR data, that we've also looked into during the course of this project, which is way higher resolution," he said. "We actually rode on the crater of Mount St. Helens off a test that another company did for us [using LIDAR data]."

Either way, Batty said, looking to real world data to inspire in-game imagination "gives you this great starting point that has this great authenticity to it."