Issue: Volume: 23 Issue: 7 (July 2000)

Real-time Racing

An innovative on-line PC game lets racing fans compete in actual Indy events

By Karen Moltenbrey

Have you ever wondered what it's like to get behind the wheel of an Indy car, zoom around the track at the Indianapolis 500, and get the wave of the checkered flag? Now, racing fans can trade in their backseat-driver title and com pete against the actual performances of Buddy Lazier and other Indy Racing League (IRL) champions in a new on-line racing game.

Developed by AniVision of Huntsville, Alabama, the Net Race Live game places Internet players in the driver's seat of a virtual Indy car, which is inserted into data captured from actual Indy events. Within 20 minutes of an Indy race's completion, all the track data from the event-including each pit stop, caution flag, and crash-is streamed to the company's Web site (, where a player can participate in a re-created simulation of the event.

"If you enter the Indy 500, for instance, you race as the 34th car (in a field of 33 actual participants), or you can narrow it to just one challenger, to race against your favorite driver," explains Jeff Boyken, director of Net Race Live.
Net Race Live pits players against their favorite drivers by mapping a gamer's virtual car into a scene containing actual event data collected during real Indy-sponsored races. (copyright 2000 AniVision.)

The racing simulation debuted following the Indianapolis 500 during Memorial Day weekend, and will continue throughout the year. Ani Vision signed a multiyear exclusive deal with the IRL to collect trackside telemetry data (such as car position, speed, cornering information, steering position, G-Force, lap times, and gear selection) from participants in all Northern Light Indy Racing Series events.

From strategically placed computerized sensors on the cars, the game developer collects the information and streams it to the Web site through a 56k dial-up connection. There, a series of proprietary al gorithms process the information and map it into a pre-modeled 3D virtual re-creation of the venue. "Spotters" at the ac tual races augment the data collected from the sensors by relaying certain events, such as when cars bump, via two-way radio to a Net Race Live programmer, who inserts the event into the game.

To play, gamers connect to the Ani Vision game server using, at a minimum, a PC Pentium II (266mhz with 32mb of RAM and an 8mb 3D graphics card) for optimal performance. Once users download the Net Race Live player, they're ready to start their engines. When the event has occurred, all the simulations will be available on the site in definitely for players to access.
Before each race, a team from AniVision photographs the vehicles and race venue so all the game graphics, including sponsor logos, are identical to those from the actual event.

"What makes this game unique is the reality aspect of it. Once you slip up, you're half a lap behind in the race, and the other drivers aren't going to wait for you to catch up, like in many other racing games," notes Boyken. "You aren't racing against [artificial intelligence] that's very predictable, where once you memorize the moves, the fun's over. Here, you're racing against real performances of real drivers like Al Unser Jr. and Eddie Cheever." At every race, these drivers create new moves and events that translate directly into the data streams. So, unlike traditional games where everything is strategically set by a programmer before the game is shipped, Net Race Live changes with every race, as driven by the pros, he adds.

To accurately re-create each racing event, Ani Vision animators modeled the cars and the venues using Discreet's (Mon treal) 3D Studio Max, even utilizing CAD data of the locations whenever it was available. A few weeks before each event, the AniVision team photographs every detail at the locale-even the billboards-from which they will generate photorealistic textures using Adobe Systems' (San Jose, CA) Photo shop.

To accommodate any last-min ute alterations to the vehicles prior to a race-such as new sponsorship logos-Ani Vision stations ar tists at the IRL technical inspection sites before each event, where they photograph every vehicle before it reaches the track. Within a half-hour, a team of AniVision artists generate the appropriate textures for the cars, so whenever a player taps into the site, the new textures are automatically downloaded, so "what they see is exactly what the car looked like for the race," says Rusty Courson, 3D animator for Net Race Live.
To ensure the realism of a 3D racing venue, all the imagery must be approved by the Indy Racing League before it can be uploaded to the Net Race Live game site on the Internet.

Achieving such graphic realism for a venue as large as Indianapolis Motor Speedway, with all its unique features-including the stands, water towers, flagpoles, and its infamous yard of bricks at the start/finish line-and getting it to run well on a player's 8mb graphics card proved especially difficult. To render the images in real time, the developers used Numerical Design, Ltd.'s (NDL; Palo Alto, CA) Net Im merse game engine.

NetImmerse also provided the necessary dynamic collision detection for the game's realistic high-velocity crashes, while its continuous level-of-detail feature optimizes the scene by reducing the number of polygons used by objects that are farther from the player's view. "For in stance, continuous level of detail reduced our 800-polygon car model down to only 50 polygons as the car moves away from the camera," says Bob Case, an AniVision software engineer.

By choosing an off-the-shelf game engine, AniVision was able to bring the game to market much quicker since it could better deploy its personnel in other areas of the game's development. "Using NetImmerse, we were able to stay focused on our core competencies-telemetry gathering, data visualization, and the In ternet," Case explains.

The biggest challenge in developing Net Race Live, Boyken says, was accurately depicting the gamer's virtual car as it interacts with the race cars re-created from the streamed data. This was accomplished through in-house-developed algorithms and rule sets that would prevent the two types of vehicles (virtual and streamed) from overlapping and forcing one another off the track.

"The cars perform as they did in the real race, but they still recognize the player's presence and react accordingly as much as possible," says Perry Adams, an AniVision software engineer. For example, if the player's car is moving too slowly down the front straightaway, the event data would have the cars running through the virtual vehicle. However, an algorithm forces the cars to alter their path somewhat to avoid hitting the player's vehicle. "If the player does something really stupid-such as cutting off the other racers or trapping them in corners-the actual cars will force his virtual car to wreck," says Boyken. Unlike the virtual vehicle, though, the real cars are fairly "immortal," to the point where the player can do little to affect their performance since it's a replay of actual data.
Game data is collected through sensors placed on the cars and is then streamed to the game Web site. Subtle events, such when cars lightly bump each other, are relayed to the programmers by on-site spotters.

This patent-pending technology was derived from concepts AniVision developed as early as 1993 to train US soldiers in vir tual battlefield simulations. "We learned how to acquire data in real time off a vehicle's system and stream it over the In ter net using a very low bandwidth connection," Boyken says. "For Net Race Live, you can race against 33 other cars at In dian apolis using a 56k dial-up connection. The majority of other games just can't handle that."

Besides challenging your favorite Indy drivers, Net Race Live lets you test your skills against other virtual challengers, where players have the opportunity to win the Net Race Live Indy Championship title by accumulating points, just as real Indy racers do.

"Many fans fantasize about racing alongside their favorite drivers," says Brian Mitchell, AniVision president. "Net Race Live makes that dream a reality by letting Indy racing fans become part of the action."

Key Tool NetImmerse, Numerical Design, Ltd. (