ONE-eyed zombie with bloodied teeth lumbers toward you through the South American mountains. Such beasts appear everywhere you look. Each swipe of their hideous arms reverberates through your body, or at least through your fingertips.

But the thud of their blows is really just the pulse of a 25-gram motor releasing 150 grams of force against your palm through a computer mouse. The beasts are the product of sophisticated shadow-rendering algorithms exploiting a 3-D accelerator card in the game Serious Sam: the Second Encounter.

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These are among the latest ways in which video game programmers have found new ways to cast consumers inside a virtual world.

Improvements in graphics and sound have already raised the bar. Now, the physically immersive technology known as haptics is beginning to deliver on the science-fiction dream of interactive alternative realities. Innovations with roots in automotive and medical engineering are making gamers feel a part of their games as never before.

Haptics technology explores how peripheral computing devices can impart force and vibrations in response to what is taking place on the screen. The military began research in the field in the 1960's. Later the focus shifted to bringing a more tactile computing experience to users of medical and automotive technologies.

Now companies are racing to bring the technology to the entertainment market. One new peripheral, Essential Reality's wireless P5 glove, allows its wearer to move and act within a gaming world through an optical tracking system. For example, a player wearing the glove in the first-person shooter game Unreal Tournament 2003 can depress a trigger with the flick of a finger.

Other new haptics devices are in development, most in the area of force feedback. This takes game information from the computer and translates it into instructions for a motor or vibrator in a peripheral device like a steering wheel or a fishing rod.

"Right now, force feedback is at the level of 8-bit graphics," said Dean Chang, senior director in the computing and entertainment group of Immersion, a leading producer of haptics devices based in San Jose, Calif. "There's plenty of room for improvement."

Improvements will arise from an understanding of neurology. The founder of Immersion, Louis Rosenberg, researched the nuances of perception while completing a doctorate in mechanical engineering and robotics at Stanford University. One result is technology that aims to convince the brain that it is feeling, say, a quarter-ounce change in pressure from a haptic device. Haptic research has also drawn on the work of scientists who have inserted probes into patients' arm nerves to determine the effects of various tactile experiences.

"Ultimately, though, you can only ask consumers if they thought it was realistic or not,'' Mr. Chang said. "You can't put probes in their brain and measure."

High-end medical and automotive touch technologies in particular will likely trickle down into prototypes for the home market. The automotive industry is exploring an Immersion product called CyberGrasp, a glove that can be programmed to exert varying degrees of force on the wearer's fingers. The technology is being used by automotive engineers to give them the feel of assembling a motor virtually.

The industry is also experimenting with so-called electronic perception to create a new breed of input devices. Developed by Canesta, a small company in San Jose, this technology is a low-cost solution that allows an electronic device to create a three-dimensional image of its surroundings and respond to changes in real time. The "perception" process works by creating a relief map of a computer's surrounding area using a variation of infrared technology. The chip releases a series of imperceptible light beams and calculates an object's shape based on the amount of time it takes the light to bounce back.

An automobile manufacturer could use electronic perception technology to determine the position and size of a passenger prior to airbag deployment, a crucial factor when the passenger is a child who might be injured by improper airbag release. And the video game industry could use it to develop an entirely new and intuitive array of input devices, from a virtual steering wheel to a baseball game in which the player hurls a ball simply by moving his hands.

In the medical field, devices could use actuator motors to simulate the subtle difference between cutting a tendon and puncturing skin.

It may be only a matter of time and market demand before the sensations of everyday life become part of the gaming experience. "We can't simulate difference between cotton and satin," said Mr. Chang, "but we're working on it."

What is the ultimate conclusion of these advances? When technologists imagine the ultimate virtual world, they inevitably recall a 1987 television episode of "Star Trek: The Next Generation" called "Encounter at Farpoint." In one scene, the first captain opens a door inside the ship that reveals, to his astonishment, a lush garden of Eden. The captain looks around and steps dubiously inside, only to see the door fade, leaving him in this paradise. "I can't believe these simulations can be this real," he says with awe.

He was at the Holodeck, which could simulate immersive environments for relaxation and entertainment. It wasn't the first imagining of an immersive virtual world, but it presented just the kind of experience that feeds the imaginations of video game engineers.

Still, it remains to be seen whether a more convincing experience is necessarily the kind of immersion players want. Reality, after all, is what a gamer wants to escape.