Six Degrees of Freedom: Why More is Better in Virtual Reality
Many people aren’t aware of the differences between 360 video and immersive VR. At Foundry 45, we have worked with both. There is a fundamental difference between the two main types of immersive experiences: interaction with the virtual world. In order to discuss this we need to understand degrees of freedom, and how they relate to user experience in virtual reality.
Degrees of Freedom
Degrees of freedom refer to the number of directions in which a rigid object can move in a 3D space. In terms of VR, the degrees of freedom refer to the number of directions a user can move in the virtual space. VR headsets on the market offer either three degrees of freedom (3 DoF) or six degrees of freedom (6 DoF).
3 DoF allows the user to move in the following three directions:
6 DoF adds three more directions in which the user can move:
Now that we understand degrees of freedom, let’s compare 360 degree video with immersive VR.
- 360 video: These are videos that are shot using special omnidirectional cameras. The user is ‘teleported’ to the location where the video was shot and can look around their surroundings. Because 360 video limits users to 3 DoF, the user is merely an observer and cannot move around. This also prevents the user from interacting with the environment and engaging with content in a hands-on manner.
- Fully immersive Virtual Reality (VR): An immersive VR experience is created using high-end graphic design and 3D modelling software. It aims to create a completely virtual world in which the user can move around and perform actions. In 6DoF experiences the user can move in all six directions, allowing them to explore their environment and to fully engage with the material.
Both the above technologies have their applications but Immersive VR is becoming the preferred technology for digital immersion.
As mentioned before, developers create 360 video by using special cameras that record an omnidirectional view of a given surrounding. Although it gives a very life-like view of the surrounding, it poses multiple challenges in creating an immersive experience.
- 360 video offers only three degrees of freedom. As discussed above this limits the movement of the user in the virtual environment. The major complaint from the user-experience standpoint is that users can sometimes feel nauseated while navigating through the experience. This is caused by a phenomenon known as sensory conflict. Sensory conflict occurs when the information received by the eyes does not match up with what the body feels.
This problem occurs more frequently with 3 DoF experiences as by definition there are only three ways the user can move in the virtual reality experience. There is also an element of depth that is missing in a 3 DoF virtual experience. The combination of these restrictions in the user’s movements causes a disconnect with what the body is used to in the real world, leading to nausea.
- 360 video limits the user’s interaction with the VR environment. 360 videos are recordings of live action. This limits what developers can include in a VR experience. The level of interaction is therefore restricted to simple kiosks and button-pressing which are not sufficient to create an immersive experience.
- Changes to 360 videos are costly. Because 360 video is a recording of actual people on an actual set, any changes to be made necessitate reassembling talent, sets, props and film crews. Even minor changes require significant filming, which take up valuable time and resources to put together.
Immersive VR places a user in a virtual world in which they decide what to do, because they are actually there and things are happening in real time. At Foundry 45, we create experiences exclusively in 6 DoF. This provides a more immersive experience that imitates real-life more closely than watching a 360 video.
- Immersive VR allows for 6 DoF. Providing 6 DoF makes user’s movements more realistic. The user can perform tasks like extending their hands which makes actions such as picking up objects and using tools feel closer to reality. Also, because the user’s movements in a 6 DoF VR environment mimic the real world better, there is less sensory conflict and users do not feel nauseated in the experience.
- Immersive VR allows for interactions that would be impossible in 360 video. Because objects in immersive VR are all created through computer graphics, there is room for creativity with interactions in the VR environment. Developers have the liberty of going into great detail when designing experiences in immersive VR, which is essential for training use cases.
As an example, VR training solutions for machine maintenance requires the freedom to move in six degrees. The user must be able to interact with objects in the virtual world as they would in the real world. Although it is possible to create such training using 360 video, it would lack the ability for users to interact with the machine and be no more effective than a training video.
- Immersive VR allows for changes at any point in production. Unlike 360 video, changes can be made at any time without the need to go back and redo previous content. Because of this flexibility immersive VR lends itself to agile development, saving costs when compared to traditional development processes.
The right tool for the job
To sum it up, there are use cases to both 360 video and immersive VR. The former can be utilized as a sales and marketing tool where the objective is a one way communication to the user. However, if the application involves the user interacting, learning and engaging with the virtual experience, immersive VR is the clear winner. This is why Foundry 45 develops the best VR experiences for employee training purposes. Allowing the employee to actually perform the actions is what helps the learning process. Without that it’s just a fancy training video.