Simlog Notes about new VR Headsets (and why they're not suitable)


New generation off-the-shelf VR Headsets from Samsung, Sony, Oculus (Facebook), HTC, etc. are generating increasing interest as display devices to make visual experiences more "immersive" e.g. to explore a virtual (simulated) world.


The objective is to track changes in the position and orientation of your head in order to present appropriate visuals on the two small displays in the VR headset right in front of your eyes.


At Simlog, we believe that such VR Headsets are not (currently) suitable for training simulation, for the following reasons:


  • In the real world, when you look forwards, you also see to the left and right. But with VR Headsets, the field of view is extremely limited, often not even 80 degrees, so you must turn your head to "see" left and right Conversely, a setup with three "front" displays can provide a field of view of 180 degrees all the time (without, of course, having to move your head).

  • The growing popularity of home entertainment systems has brought the price of "big screen" displays, especially LED HD TVs, within reach of every training budget. As a result, there is there little, if any, cost savings to purchasing a single VR Headset compared to three or even four multiple displays.

  • Wearing a VR Headset limits what you see to just the simulated world. For that reason, it can be difficult, for example, to reach for a forklift lever with your right hand (in the real world) because you cannot "see" the lever or your hand. Some VR Headsets attempt to overcome this problem by adding cameras to "superimpose" what the cameras "see" on top of the simulated world to create "augmented reality", at added cost.

  • Compared to multiple displays, using a VR Headset requires special care. First, the weight on your head, and the display fitting tightly over your eyes (to block out the world around you) makes it uncomfortable to wear for extended lengths of time, so you will be taking it on and off very often as you train. And all that "on and off" per student, times many students, inevitably leads to an increased risk of damage to the device (as well as to other problems related to hygiene). For that reason, using multiple displays is not only simpler, but much more "robust" because once the setup is complete, there is no "handling".

  • Many people experience motion sickness with VR Headsets. Here's why. The frame rate of typical simulation software (and video games) is about 30 Hz, meaning that about 30 times a second, your computer must detect a change in input (moving a joystick, pedal, etc.), decide what to change in the simulated world, perform lots of calculations about the changes, and then render those changes to see and hear the results. However, today's VR Headsets require visuals to be "refreshed" at more than 50Hz, perhaps as much as 90Hz according to some accounts.

    For that reason, when you turn your head to look in a new direction, there may be noticeable latency, or time delay, until a new view of the simulated world is displayed that reflects looking in that new direction, and that's the source of the motion sickness. This is especially true when simulated objects are moving quickly with high accelerations, making quick starts, stops and turns. This is why some research suggests limiting the duration of a typical training sessions with VR Headsets to just 15 minutes at a time. And that limitation poses an additional problem, because people typically train for an hour at a time at a simulator (airplane pilots, astronauts, and heavy equipment operators).

  • Finally, using a VR Headset alone means that only the student can "see" what is going on. So for an instructor to monitor the progress of the student, or for a second student to learn by watching the first one, an additional, conventional, display is required in any case, at added cost.


For all of these reasons, Simlog continues to believe that simulator-based training with multiple displays offers a superior simulation experience compared to VR Headsets. To learn more, please contact Simlog.



REFERENCES

"Sensory Supplements", MS&T - The International Defence Training Journal, Halldale Group, Volume 34, Issue 3, Summer 2017.

"The virtual reality head-mounted display Oculus Rift induces motion sickness", J. Munafo, M. Diedrick, T. Stoffregen, Experimental Brain Research, Volume 235, Issue 3, March 2017.