6DoF vs. 3DoF: Degrees of freedom in VR explained

This blog often discusses VR training and immersive learning from a practical and conceptual vantage point, underlining why this new technology capability is so groundbreaking for L&D organizations. But that doesn’t mean we don’t get deep into the technical weeds in our day-to-day work, and that includes, of course, when it comes to VR devices.

You probably didn’t even click on this blog link unless you’re already researching VR headsets, also commonly called head-mounted displays (HMDs). VR headsets are an integral part of the experience of immersive learning — or any virtual reality experience, for that matter.

6DoF vs. 3DoF

Degrees of freedom (DoF) refer to the number of axes that are tracked within a VR experience and, accordingly, how a user can move and interact within that experience.

3 degrees of freedom (3DoF) refers to the 3 rotational axes, which allow:

• Turning the head left or right (yawing)
• Looking up or down (pitching)
• Tilting the head side to side (the ear-to-shoulder movement known as rolling)

6 degrees of freedom (6DoF) includes 3 additional translational axes, which allow:

• Moving the body left or right (strafing)
• Moving the body forwards or backward (surging)
• Moving the body upwards or downwards (elevating)

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With 3DoF, you can only move in rotational ways, which essentially means you can only move your head. You can’t actually move your body around in space or get closer or farther from objects in the line of vision. But with 6DoF, you can move around the room.

360° content vs. immersive VR

If you’ve ever gone real estate window shopping online or tried to book a high-end property, you may have come across 360° content: photos or videos that enable you to look around by moving your mouse. 360° content gives you a “spherical view,” which is a vast departure from 2D photography but has limitations. For one thing, the user in the headset can only look around and experience the “view” by rotating.

3DoF is good for viewing 360° content. While it can be “enriched” by interactions, they are limited. There’s no way to move closer to or further away from objects in the field of vision — so there’s no way to go beyond what’s ultimately a pretty basic experience. Once you’ve seen all 360 degrees, that’s it.

To have a truly immersive experience inside a scene, you need 6DoF, with its orientation along six distinct axes. The 6DoF model enables a fully simulated 3D world that can be inspected and explored in detail. Imagery is rendered from every orientation, and the user can move around inside the experience.

To put it bluntly, with 3DoF, the user is observing. With 6DoF, the user is fully involved.

It’s important to note that headsets designed for 6DoF viewing can also handle 3DoF content, but the opposite is not true. A 3DoF device can only display 3DoF content. That includes VR devices like Oculus Go (which was discontinued a few years ago for this very reason).

True immersive learning requires 6DoF

At Strivr, when we talk about VR headsets, we’re primarily concerned with their use in immersive learning or VR training, and in this realm, there’s no comparison. You have to use 6DoF in order to have a deeper degree of control over movement in the environment.

What makes immersive learning different from other kinds of VR is not just that the subject matter is training-based. Immersive learning is an experiential training methodology that combines the highly realistic simulations of VR with advanced learning theory, data science, and spatial design.

For L&D organizations, a large part of the value of immersive learning is the data and metrics it provides both on individual learners and organizational goals. However, that data and insight would not be accurate or meaningful if the experience itself was not engaging and effective, and 6DoF experience makes a huge difference in this regard.

Learners within the headset experience immersive learning in a highly realistic way because they can interact and move along all six axes. They're not limited to a rotating 360° viewpoint but can move forward or backward within the experience, step to the side to avoid a hazard, use their hands to operate machinery, and more. 6DoF is an important factor in this experience, making the user’s in-headset experience more realistic and giving them a higher degree of agency over the actions they take.

The trend is clearly toward 6DoF, so while you can probably get your hands on a 3DoF headset with less cost, it’s not a great investment at this point.

If you’re curious to learn more about  immersive learning, including the technology behind Strivr’s offerings, read The ultimate guide to immersive learning.