Before you actually start with any Virtual Reality, you will need to make a choice for a headset. At the HMI-lab we have a number of different Headsets available. The word Headset and HMD (Head-Mounted Display) tend to be used interchangeably for these items.

All of these headsets were released around different times and have different pro's and con's for certain usages. The following is a list of all available headsets in no apparent order with links to their respective pages.

• Fove
• Valve Index
• HTC Vive
• HTC Vive Pro
• HTC Vive Pro Eye
• Oculus Quest 1
• Oculus Quest 2

The specifications down below are according to the pages referenced.

	Fove (1)	Valve Index (2)	HTC Vive (3)	HTC Vive Pro (4)	HTC Vive Pro Eye (5)	Oculus Quest 1 (6)	Oculus Quest 2 (7)
Resolution per Eye	1280 × 1440	1440 × 1600	1080 x 1200	1440 × 1600	1440 x 1600	1440 × 1600	1832 × 1920
Refresh Rate (Hz)	70 Hz	144 Hz	90 Hz	90 Hz	90 Hz	72 Hz	72 Hz
Field of View (degrees)	100	130	110	110	110	90	90
Tethered	Yes	Yes	Yes	Yes	Yes	Yes	No
Tracking Method	Fove/SteamVR Stations	SteamVR 2.0 Stations	SteamVR 1.0 Stations	SteamVR 2.0 Station	SteamVR 2.0 Stations	Headset	Headset
Tracking Area*	Seated	5mx5m (2), up to 10mx10m (4)	5mx5m (2), up to 10mx10m (4)	5mx5m (2), up to 10mx10m (4)	5mx5m (2), up to 10mx10m (4)	2mx2m for room-scale	2mx2m for room scale
Game Engine Integrations**	Unreal, Unity	Unreal, Unity	Unreal, Unity	Unreal, Unity	Unreal, Unity	Unreal, Unity	Unreal, Unity
Release Date (YYYY-MM-DD)	2017-01-22	2019-05-01	2016-04-05	2018-04-05	2019-06-06	2019-11-18	2020-10-13

• * : These are the specs published, real world experiences might vary based on size of the tracking space.
• **: Integration capacity as given by manufacturer, ease of implementation might difffer. Do your own (google) research.

For more info see: VRcompare and wikipedia

Depending on what the goal of your research is going to be, a few choices can be made. Not every headset given above is a good pick for every kind of research, as their design differs. Not all of these choices will be clear from the table up above, therefore we have made a small list.

A few of the most common selection criteria:

• Set-up anywhere: Oculus Quest 2, (HTC Vive Pro could technically do this, but HMI does not have the required parts;
• Tracking extra objects: Any SteamVR connectable HMD, such as the HTC Vive and Valve Index and their variants;
• Eye-tracking: FOVE or HTC Vive Pro Eye.
• Room-size free movement: Any HMD should work, see table for size. FOVE is exception
• Integration with other devices: Some other devices only work on specific environments and/or integrations. Often at least SteamVR and Oculus integrations are offered. Check the manufacturers websites/manuals for precise details.

Usually, multiple options are still available after looking at these selection criteria. After this the next best option is to ask your supervisor and people around you if they have any knowledge or experience.

Most VR devices have integrations available with either Unreal or Unity. Both of these are widely used game engines with editors in which a visual representation of the environment is visible. Both have a drag-and-drop method of creating things, but more powerful functions are hidden in their scripting/programming interactions.

For scripting the choice between Unity and Unreal is slighly different. Unity supports C# (C-sharp), while Unreal supports C++ (C-plus-plus). In general, C# tends to be more friendly for new programmers, although it's learning curve is still quite steep.

Other integrations might exist or be created, but these two are the most supported engines out there right now.

• When starting, try finding a 'how to set up' video or guide. This can help figuring out how to best approach

• When starting with a HMD it is okay to just play around with it. This will give you a feel of what the device can do, but also what VR itself can do. The HMI steam account has some VR games.

• Don't be afraid to play with the focus distance and between-eye distance of the HMD, this might with finding a comfortable experience.

• Keep your accessories charged when you expect you will need them. They don't have large batteries.

• Don't change the core of your developing set-up too often. It might be tempting to try out a new update of a piece of software, but in the case of VR integrations this generally causes a lot of headaches and fixing problems. Stick with the versions available when you started developing something
• Make back-ups! VR is sometimes finicky and you can loose progress or break something with a few wrongly placed clicks.
• Explore what other people have done on the internet!

• Learn Unity Basics: A tutorial about Unity (not VR) that goes over all the essential basic skills and knowledge for setting up and developing games in Unity with C#
• raywenderlich.com: A programming website which can be helpful for a lot of general progamming/implementation topics in VR.
• reddit.com/r/virtualreality/: Community full of VR enthusiasts, can give a good grasp on experiences which exist/are possible.
• Youtube: Fairly self-explanatory, but most games video's of people playing them on Youtube. Easy to check out. Also useful for developing
• Games:
  • The Lab: a VR experience created by Valve, good exploration of possiblities
  • Tilt Brush: A VR drawing tool by Google.
  • Beat Saber: One of the most popular VR rhythm games.
  • Keep Talking and Nobody Explodes: A thrilling bomb-defusing game, 2+ players.