🔍 XR Under the Microscope

Other Key Terms Every Virtual Technology Enthusiast Should Know

In the previous article, we explored the basic concepts of VR, AR, and MR.

If the world of virtual technologies has caught your interest and you want to go further, you’ve probably already come across abbreviations like FOV, 6DoF, or terms such as passthrough and hand tracking.

But what do all these mean?

In this article, I’ll walk you through the key terms and concepts that will help you better understand how XR technologies actually work.

XR Under the Microscope

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👁️‍🗨️ FOV (Field of View) – Field of Vision

FOV defines how wide a “slice of reality” your headset displays — in other words, how much you can see at once. For example, the human eye has a natural field of view of about 210°. Older VR headsets offered around 90–100°, while newer models (like the Quest 3) reach 110–120°.

Why does it matter?

The wider the FOV, the more natural and immersive the experience feels. A narrow FOV can make users feel confined or claustrophobic.

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🧭 6DoF vs. 3DoF – Degrees of Freedom

This abbreviation stands for Degrees of Freedom, referring to how freely you can move within XR:

• 0DoF – The user cannot look around or move at all. It’s a static, non-interactive experience.

• 3DoF – Head movement only (rotation: up/down, left/right, tilt).

• 6DoF – Includes spatial movement (forward/backward, up/down, sideways).

Modern XR experiences almost always use 6DoF. Headsets like Meta Quest or HTC Vive allow full movement through virtual environments, while cheaper mobile-based headsets typically support only 3DoF — rotation of the head without positional movement.

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🎥 Inside-out vs. Outside-in Tracking

XR devices must know exactly where you are in space, and there are two main tracking methods:

• Outside-in tracking – Uses external sensors (e.g., SteamVR “base stations” with HTC Vive).

• Inside-out tracking – Uses cameras built directly into the headset (e.g., Meta Quest, Pico).

Today’s trend is clear: inside-out tracking is more practical because it doesn’t require any additional hardware. Just put on the headset — and you’re in the game.

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🕶️ Passthrough – Seeing the Real World

Passthrough allows you to see the real world through your headset, usually using built-in cameras.Color passthrough (as on Meta Quest 3) is the foundation of mixed reality, where virtual objects are overlaid naturally onto your physical environment.

With passthrough, you can:

• Interact safely with your surroundings,

• See your hands or keyboard,

• Combine AR and VR experiences seamlessly.

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🧠 XR Engines – Where Virtual Worlds Are Built

Most XR applications today are developed using one of two main engines:

• Unity (highly recommended for accessibility, SDK integration, and XR simulation design)

• Unreal Engine

Both engines support VR and AR development, and even beginners can create their first interactive XR projects. If you’re curious about XR from a creator’s perspective, this is where the fun truly begins.

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✋ Hand Tracking & Eye Tracking

• Hand Tracking – Recognizes and follows hand movements without controllers.

• Eye Tracking – Tracks your gaze, allowing you to focus or control the interface with your eyes.

These technologies are changing how we interact in XR — no buttons, just natural movement — and they also open new possibilities in accessibility, gamification, and user experience design.

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🧭 Locomotion in VR – How We Move

In VR, you can’t just run freely around your room. To ensure safety, you define a play area boundary when setting up your headset. Within this space, movement methods vary:

• Teleportation – Point and instantly move to a location. Reduces motion sickness.

• Smooth locomotion – Continuous joystick movement, like in traditional video games.

• Room-scale – Physical movement within your real-world space.

• Omnidirectional treadmills (e.g., Kat Walk) – Let you “walk” in any direction while staying in place. These setups are rare and mostly found in specialized VR arcades.

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🧠 Summary

The XR world is like an onion — layered and rich. The deeper you go, the more you discover how amazing and complex these experiences can be. Even if you don’t need to understand every detail, knowing the basics helps you become a more confident user — or even a future creator.

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🔜 Coming Next:

In the next article, we’ll look at one of the most common challenges for VR beginners — motion sickness, the discomfort often associated with using VR headsets.