Degrees of Freedom… 3DoF vs 6DoF

Degrees of Freedom… 3DoF vs 6DoF

With more and more being written about VR, we can sometimes get mired in not fully understanding the jargon. Today, we’ll look at degrees of freedom, or DoF. This term refers to the ways that you can move within a 3D space. There are three main axes (rotational) and three secondary axes (translational).
Rotational terms include:

•  Pitch (x-axis, blue line)

• Yaw (y-axis, green line)

• Roll (z-axis, purple line)

Translational terms include:

• Sway (x-axis, light blue line)

• Heave (y-axis, orange line)

• Surge (z-axis, red line)

3DoF means that you are governed by rotational movements. 6DoF means that your experience in VR will be extended to include translational movements. The quickest way to understand this is to watch this informative YouTube video, which is less than 2 minutes long.

Which is “better?”

At first blush, a Lamborghini may be thought of as a “better” car than a Toyota Camry. It has more horsepower, a stylish design and of course costs a whole lot more. But if you are looking for a very good, functional and practical car which can get you where you need to go for your everyday needs, then the Camry is the favoured choice. It also leaves you with enough money to buy gas.

The same can be said for 3DoF vs 6DoF VR devices. Consider the intended use and application, and whether those will be satisfied by a Camry, or require a Lamborghini.
Preferred uses of a 6DoF device:

• Entertainment and gaming

• High-end industrial needs requiring customized content

• Specialized medical procedures and intricate uses (high processing power needs)

Preferred uses of a 3DoF device:

• Education, which requires access to a wide range of content

• Where you may want to restrict movement (classrooms) for the sake of safety

• Simpler needs where extra immersion doesn’t significantly contribute to outcomes

The Economics of VR

Over the last number of years, a 6DoF device meant buying a VR device and also buying a powerful PC to offer up the processing power required for the increased demands of that device. For entertainment and gaming, this was an acceptable expense for many (although not most, as the market has proven out). For single users at a time, industrial training and university research, this was an understandable expense. But that sales model could never sustain in education, even for private schools with fewer budget concerns, as the content was still at its infancy and thus was expensive to acquire. Lamborghinis without gas.
This is where a 3DoF solution is a better fit. Just as you can imagine a fleet of Camrys (but not Lamborghinis), a 3DoF device can be deployed en masse throughout a school district for these reasons:

• Cheaper to buy, easier to use

• No physical movement is needed (other than rotating in place), which is safer

• An abundance of content is readily available, the gas that drives education

• Learning outcomes are not sacrificed by not having translational movement

Conclusion

Currently, 6DoF devices are more expensive than 3DoF, but the price is dropping. However, even if priced the same, the fact that there is still a scarcity of curriculum-aligned, interactive, educational content for 6DoF available is a troubling fact. The same cannot be said about 3DoF, for which a jaw-dropping plethora of content exists (https://learn.veative.com/modules).

If you require specialized content and have the time and money to get that made, then a 6DoF VR is “better” choice; however, it is not the preferred choice for education. One day it will be… but that day is not today.