If you're a bit familiar with virtual reality goggles, you'll have come across the term 3DoF and 6DoF in relation to tracking. What exactly is meant by this.
3 DOF (Degrees of Freedom) and 6 DOF are terms that refer to the freedom of movement of a VR headset.
3 DOF (Degrees of Freedom) ergo only head tracking
A virtual reality headset with 3 DOF only captures the rotations of the user's head around the Pitch, Yaw and Roll axes. This means that the user can tilt their head up and down, turn left and right, and tilt their head to the side. The headset is not able to detect if the user is walking or leaning forward or backward. A virtual reality headset with 3 DOF can be used in situations where the user is primarily performing static or sedentary activities that do not require movement around the room. It is also beneficial when providing seating to show content that only allows rotation tracking.
Popular 3DOF headsets on the market: Current shark sets in this category are Pico G2 and Pico G3
Older models like the Oculus Go are no longer sold, but are still used for presentations and trade shows.
Lower acquisition costs: 3 DOF headsets are usually much cheaper than headsets that enable position tracking.
Less space required: Without position tracking, 3DOF headsets do not require a special room or special sensors. This makes them ideal for situations where space is limited or movement is not possible, such as when sitting on an airplane.
Less battery consumption: Since 3DOF headsets require fewer sensors and processing power, they may consume less power and last longer than 6DOF headsets.
Simpler setup: Without external sensors or base stations, 3DOF systems are often less complicated to set up.
Portability: Many 3DOF headsets are lighter and more compact, making them more portable. This is ideal for use on the go or for quick VR sessions without much preparation.would be for example:
Applications for 3DOF headsets
here are examples of applications that also run best on 3DOF VR glasses.
- 360° photos
- 360° photo tours
- 360° videos or 180° videos of any kind
- Virtual tours or guided tours
Google Cardboard - The cheap 3DOF "headset
Another product in the smartphone VR headset category is the Google Cardboard. you can argue whether this is a headset or rather a gimmick. As the name suggests, this headset is mainly made of cardboard and serves as a simple and extremely inexpensive introduction to the VR world. Users fold the Cardboard into the right shape, insert their smartphone and use the Google Cardboard app to experience various VR experiences. The VR apps are iOS or Android apps from their respective app stores that support a Cardboard function. Despite its democratic approach to making VR accessible to everyone, the Google Cardboard has some significant weaknesses that significantly reduce its quality compared to other VR solutions:
Poor material: The cardboard material does not provide the durability or comfort of professionally manufactured plastic or cloth headsets. It can be easily damaged and is not ideal for extended periods of use.
No specialized hardware: The Cardboard relies entirely on the smartphone for both rendering and tracking. This means that there are no special sensors or controls that could improve the VR experience.
Simple lens design: The lenses in the Google Cardboard are not as high-quality or as accurately calibrated as those in more expensive headsets. This can lead to less clear pictures and possible distortions. Furthermore, the field of view is clearly restricted (tunnel vision).
Compatibility and fit: Because it is designed for a variety of smartphones, there is no one size or shape that is perfect for all devices. This may cause problems with the display or insertion of the smartphone.
All these weaknesses are probably the reason why the use of Cardboards as a presentation medium for VR content or 360° videos is declining strongly.
There have also been 3DOF VR headsets in the past that have more complex lenses and plastic housings. Examples of such products were the Samsung Gear VR and the Google Daydream View. Both are holders into which a compatible smartphone is inserted. The associated lenses of the headset then enlarge the image displayed on the smartphone so that it fills the user's entire viewing area.
Despite their simplicity and accessibility, these smartphone-based VR headsets cannot compete with standalone solutions in terms of quality.
6 DOF (Degrees of Freedom) ergo head tracking plus position tracking
A VR headset with 6 DOF also allows the user to move spatially in space in addition to rotating the head. This means that the user can move within the virtual space by moving forward, backward, left or right and can also move up and down. The headset thus not only detects the head's rotations, but also its movements in space.
A VR headset with 6 DOF, on the other hand, is required in activities that require spatial movements, such as:
- Virtual games or sports activities, where the user has to move in different directions
- Virtual conferences or collaborations with other users in the virtual space, where the user can move within the virtual space and interact with other users
- Virtual simulation of real-world activities, such as flight or vehicle control, where the user must perform various movements in space.
It is possible to cover all applications with a 6DoF headset that a 3DoF headset can play, but the reverse is of course not the case. 3DoF headsets like the Pico G2 and Pico G3 are more affordable and easier to use. This aspect can be decisive, especially when it comes to virtual reality presentations with many participants. 6 DoF headsets like the Meta Quest, Pico 4 and Vive Focus are real all-rounders. However, they also cost considerably more.
Overview of 3DoF and 6DoF headsets
|VR headset||DOF||Controller||Tracking||Price||Year of publication|
|Pico G3||3 DOF||Touchpad controller||Head tracking||ca.350€||2023|
|Oculus Quest 2||6 DOF||Two touch controllers||Inside-Out Tracking||from approx. 350€||2020|
|Pico 4 Enterprise||6 DOF||Two touch controllers||Inside-Out Tracking||from approx. 600€||2022|
|Meta Quest pro||6 DOF||Two touch controllers||Inside-Out Tracking||from approx. 1200€||2022|
|HTC Vive Cosmos Elite||6 DOF||Two SteamVR controllers||Lighthouse tracking||from approx. 900€||2020|
|Pico G2||3 DOF||Touchpad controller||Head tracking||ca.300€||2015|