Inside THRILL Rides!

The newest "scream machine" makes you feel like you're plunging five stories to your doom--without lifting you more than a few feet in the air!

A gang of villains straight out of Spider-Man comics has kidnapped the Statue of Liberty. They threaten to take New York City hostage. Your mission: help Spider-Man nab the outlaws. You climb aboard the "Scoop," a futuristic takes you on a crash course through Manhattan's back streets.

Villain bombards the Scoop, causing it to lurch and reel out of control. Suddenly, wicked Doc Octopus zaps the car with an anti-gravity ray gun, shooting you 152 meters (500 feet) into the air. Next thing you know, you're plunging headlong towards the ground! Aaaaahhhhhh!

If you thought roller coasters were the ultimate scream machines, check out America's newest thrill ride: "The Amazing Adventures of Spider-Man," which premiered last summer at Universal Studios Islands of Adventure in Orlando, Florida. Spider-Man, which cost $100 million and took five years to build, belongs to a class of amusement-park attractions called immersive thrill rides or simulator rides.

Immersive thrill rides combine larger-than-life movies with gut-wrenching motion bases (machines you sit in that tilt, sway, and roll) to trick your mind and body into thinking you're on the ride of your life. Unlike other simulator rides where the motion base is bolted to the floor, the Scoop zooms past 13 huge screens inside the theater. In addition, images you see in front of you are all computer-generated and in 3-D--characters seem to lunge from the screen at you. (Riders wear night-vision goggles, which are actually 3-D glasses in disguise.) Finally, real physical effects complete the illusion: For example, when fiendish Hobgoblin hurls an explosive jack-o'-lantern at you, you feel the heat from the blast. "It's really unlike anything you've ever done," raves Phil Hettema, senior vice president of attraction development at Universal Studios. "It feels like you've entered a comic-book world."

MAKE-BELIEVE

Using technology to fake reality is not new. The military first used flight simulators in the 1940s to train pilots to fly war planes. When the pilot pulls the plane's control column to ascend, for instance, the front of the simulator tilts up. Images on the "cockpit window" show the ground falling away.

With immersive thrill rides, you can't manipulate the simulator scenery. And forget about reality! These rides take you on a fantastical journey and convince you that what's imaginary is totally real.

To create thrills, simulator rides manipulate two factors: vision and motion. Vision is what you see in front of and around you. When you get on a simulator ride, you see a wide screen that covers nearly your entire field of view. Objects on-screen seem to fly right at you and whiz by to make you believe you're blasting through air.

Your peripheral vision--what you see at the edges of your field of view--lets you sense motion. "When you're in a car, your sense of how fast you're going comes from visual cues you get from the side," explains Ginger Watson, a simulation researcher at the University of Iowa. "But vision alone doesn't give you that much sense of motion."

Fluid in your inner ears also tells your brain whether you're tilting, swaying, rising, or falling. "But the only way your inner ear senses motion is from real motion," Watson says. That's where motion bases come in.

MOVE IT!

Simulator rides are set on a motion base that gyrates in up to six different directions, called degrees of freedom: heave (moving up and down), pitch (tilting forward and back), roll (tilting side-to-side), surge (moving forward and back), sway (moving side-to-side), and yaw (twisting side-to-side).

Most simulator rides have only three degrees of freedom--Spider-Man has all six. Computers control pistons, cylinders that move back and forth, under the motion base to rock the simulator in sync with an on-screen image. For example, the first time Spider-Man appears, he jumps on the Scoop's hood and the car bounces as he lands.

PROGRAMMED THRILLS

How does a projected 3-D image make a car jolt? Call it the magic of motion-ride programming. A ride programmer first studies screen images to decide what movements would convince viewers, for instance, that they're soaring or falling. Then the programmer uses a joystick to program the base to move in a way that fools your brain.

Take the scene where Doc Octopus lifts the Scoop hundreds of feet in the air then lets it fall. If you were actually in a car that shoots off the ground, then drops headfirst, the force of the car moving forward would thrust you back against the seat. That's because of inertia, your body's resistance to a change of speed or direction. To simulate this motion, the programmer quickly tilts the rear of the base downward to push you back. Of course, seeing the ground rush up on-screen helps convince you that you're headed for a total smash-up.

Suddenly, a gigantic web shoots out between you and the ground. The front of the motion base quickly tilts down and back up to fling your body forward as the web catches the Scoop in midair. SpiderMan saves the day!