Super Bowl: How did they get line and arrow graphics on the grass to change?

A company called http://www.sportvision.com/ provides the tech. The website is shitty and provides a perfect example of why you don’t use Flash to build a site.

Long story short: the process is similar to Chromakey or green screen technology, but opposite of how it’s normally used. The system knows only to put the line in the color of the field. The cameras that are shooting the game have a device that takes into account the angle of the lense and the amount of zoom, which is how the line is always parallel to the lines on the field.

While searching for the answer I found a great Q-and-A column from ABC News called “The Answer Geek.” The Geek lays the yellow line blame squarely on the shoulders of a company called Sportvision, who have one humdinger of a web site as john pointed out. Here’s the gist of it, but check the site for more details:

According to the site, “There are eight computers… three sets of special encoders and abundant wiring dedicated to generating the virtual first down line in video format.” The virtual line is drawn on video based on the position first down marker, ridiculously exact details of of the live camera’s position (including altitude and lens angle), a digital 3D model of the field, and two palettes of colors for the field and the players. The player’s colors automatically override the virtual line’s colors, so it appears as though they’re stepping over it.

The company recently won an Emmy for the floating yellow line, and unlike the lite-brite hockey puck fiasco a few years ago, the “first and ten” technology is very popular—a recent poll quoted on Sportvision’s site found that “over 92% of fans want the patented technology in every football game they watch, and more than 25% said that they are more inclined to watch a game that features the system.”

Sportvision has all sorts of cool new tricks up their sleeve: technology that measures the speed of a swinging baseball bat, the vertical leap of a basketball player, the height and speed of a ski jumper, and the swerving path of a NASCAR driver. So expect lots more nifty special effects soon, including a “technology enriched webcast” of the Ironman triathlon in October.

P.S. The howstuffworks article on it is pretty in-depth.