There are two types of VR in total – 3 DoF (degrees of freedom) VR and 6 DoF VR.
3DoF refers to the roll, pitch, and yaw rotation, which corresponds to human head motions, including turning left and right, tilting up and down, and pivoting left and right, respectively. Apart from the three motions in the directions mentioned above, a 6 DoF device shows an additional three translational motions along the X, Y, and Z axes. Jokingly, we call 3DoF VR the fake VR and 6 DoF VR the real VR.
The difference between these two VRs is whether they can detect users’ walking motion.
Currently, VR operated through mobile phones cannot detect users’ motion and are 3 DoF (fake VR) products. HMD (head-mounted display) devices such as Valve Index, HTC Vive, Meta Quest and PSVR are all 6 DoF (True VR) products.
And what is the difference between these two types of VRs for us? The most important difference is the cost of developing the hardware and content!
In addition, we can operate 3 DoF with just a mobile phone using panoramic image data and open a VR website with just a web browser. On the contrary, we need to buy an HMD (costing USD 300 – 1000) and a high-end computer (we may or may not need it, depending on the device type) to operate a 6 DoF device. A 6 DoF content uses 3D models to create a virtual environment, the production cost is several to tens of times higher than that of a panoramic view website. Therefore, it costs the developer and the audience a huge amount to produce and enjoy a real piece of 6 DoF (real VR) work!
From the audience’s perspective, we can use fake VR if they have a smartphone. They can even browse and operate the fake VR through the panoramic method using just a common browser. You can imagine that the audience of real VR will be far less than that of fake VR due to the needs of hardware. So, the VR technology you choose to serve as your development target depends totally on your business model, production purpose and target audience (TA)!
Wanna know how the 6 DoF VR positional tracking works? Please refer to the following: