In this blog post, we’ll explore “tracking” technology—a key issue in the VR market—examining what it is, how it works, and what obstacles stand in the way of its commercialization.
The VR Market and the Tracking War
In March 2014, public interest exploded when Facebook founder Mark Zuckerberg acquired Oculus, a VR device company, for approximately 2.5 trillion won. VR stands for Virtual Reality, a technology that allows users to view and interact with computer-generated environments as if they were real. One of the reasons that acquisition decision garnered so much attention was “tracking,” which remained a core challenge in VR development at the time.
Tracking is, quite literally, the technology that tracks a user’s movements and reflects them in a virtual environment. Key examples include head tracking, which tracks head rotation; position tracking, which tracks the user’s location; and eye tracking, which tracks eye movements. The devices currently dominant in the market are HMDs (Head-Mounted Displays), and both the HMD itself and the handheld controllers require tracking technology.
Types of Tracking and How They Work
Head tracking is a technology designed to reflect head movements in a way that feels natural to the user. Head rotation can be described in three ways: nodding the head up and down is called pitch, turning the head from side to side is called yaw, and tilting the head is called roll. These rotations are measured by an IMU (Inertial Measurement Unit), which combines an accelerometer and a gyroscope (rotation sensor), and most HMDs are equipped with this inertial sensor.
Position tracking is a technology that tracks the user’s position in three-dimensional space, ensuring that when the head or hands move in reality, the same movement occurs in the virtual world. Implementing position tracking offers the benefits of enhanced immersion and reduced dizziness. However, since HMDs block the user’s field of view, movement is restricted without a large open space, and accurate position tracking is difficult to achieve without external cameras or separate equipment. Incorporating position tracking into controllers makes hand movements more natural and expands the range of interaction.
Position Tracking and Oculus’s Approach
Oculus has developed an external infrared-based tracking method called the Constellation Tracking System. In this system, multiple infrared light-emitting diodes (LEDs) are placed on the HMD, and external infrared sensors read the pattern of these lights to calculate position and orientation. For example, when four dots form a square pattern, the pattern shrinks as the user moves forward, shifts sideways as the user moves laterally, and becomes distorted as the user turns their head. By analyzing these changes, the HMD’s position and rotation can be determined, and the more dots there are, the lower the error.
However, position tracking increases cost and complexity. Products that omit position tracking—such as those where a smartphone is simply inserted into the HMD (e.g., Samsung’s Gear VR)—are relatively inexpensive, whereas PC-based devices like the Oculus Rift, which include external sensors, were released at a higher price point. Furthermore, these devices require high-performance computers, increasing the initial cost. Ultimately, implementing position tracking has the limitation that it requires separate hardware and complex computations.
Eye Tracking and the Challenges of Mass Adoption
Eye tracking is a technology that tracks the user’s eye movements to change the screen or move the cursor. It has already been used as an assistive input method for users with limited motor skills and is similar to the technology used by figures like Stephen Hawking. However, in current VR applications, gaze-based control often causes dizziness or lacks sufficient practicality, preventing its widespread adoption. As the technology advances further, there is a possibility that it will be adopted more naturally.
Technical progress alone cannot guarantee the mass adoption of VR. No matter how much tracking improves and immersion increases, if there is a lack of “killer content” that consumers are willing to pay a premium for and enjoy consistently, it may remain nothing more than a fleeting experience. Additionally, lowering prices is crucial. The recent Pokémon GO craze has sparked growing interest in AR and VR, but AR also requires precise tracking for virtual objects to align properly with real-world coordinates. In the near future, tracking capable of replicating everything from facial expressions to full-body movements—essentially mirroring our real-world selves—may become commonplace. Ultimately, the leaders of this new era will be those who are the first to achieve perfect tracking in virtual reality.
