When it comes to Virtual Reality (VR), full-body tracking provides the ultimate experience. While having a good VR headset is important, why stop at just tracking your hands? With the help of motion trackers, attaching these additional trackers to your joints or other objects can capture real-world movements in real-time and accurately map them into the virtual environment. This allows you to move from head to toe, taking the immersive experience to the next level! VR tracking technology plays an indispensable role in various fields such as VR social interaction, VR gaming, medical rehabilitation, and professional training.
VR tracking technology perfectly unifies your body with your Avatar.
To achieve precise location tracking in virtual space, base station systems (such as the Lighthouse technology used by SteamVR and HTC VIVE Base Station) play a crucial role. These base stations act like an indoor satellite navigation system, using emitted light beams or wireless signals to locate trackers and VR headsets in the tracked space. This allows every movement and subtle action to be precisely detected, mapped, and tracked.
The advantage of this technology is its high precision, making it suitable for pro-level players or applications that require high accuracy, such as detailed motion capture or professional training simulations. The downside is that setting up base stations can be a bit of a hassle, with many variables and limitations to consider. In addition to having enough space to set up these base stations, you also need to be mindful of the layout of the space and potential issues with light reflection. Moreover, if you want to play VR in another room, you'll have to go through these tedious setup procedures again.
The setup process of using base station tracking is more complex, but correspondingly, the accuracy is higher. (Source: HTC VIVE)
If you say, "I just want to 'come alive' in the virtual world" and don't want all the hassle of doing a setup, then a lightweight and portable IMU tracker might be a good choice. For example, Sony's popular Mocopi tracker uses IMU technology and is aimed at general consumers.
IMU (Inertial Measurement Unit) is a device built into the tracker, typically using a three-axis gyroscope and accelerometers in three directions to measure and calculate the object's relative motion. These sensors provide data about the object's velocity, orientation, and acceleration, thereby inferring changes in the object's position. The benefit of IMU technology is that users can move freely without the need for any base stations to track their movements. However, this system is not perfect; IMU tracking can only provide motion data relative to the starting position, and it does not know the object's absolute position in space. Therefore, without external reference points and without strong algorithms for calibration, IMU tracking can easily and quickly accumulate errors over time, leading to “drift”, latency, and other serious tracking issues.
In response to the limitations of the two technologies mentioned above, self-tracking, which is primarily based on Computer Vision (CV) with IMU as a supplement, has emerged. This was first seen in HTC VIVE's VIVE Ultimate Tracker, released in 2023. This technology not only provides relative positioning data from IMU technology but also senses the space through two wide-angle cameras on the tracker (similar to the cameras on VR headsets), and then uses AI technology to calculate the precise absolute position in real-time.