Introduction to Virtual Reality (VR)
Virtual Reality (VR) literally makes it possible to experience anything, anywhere, anytime. It is the most immersive type of reality technology and can convince the human brain that it is somewhere it is really not. Head mounted displays are used with headphones and hand controllers to provide a fully immersive experience. With the largest technology companies on planet earth (Facebook, Google, and Microsoft) currently investing billions of dollars into virtual reality companies and startups, the future of virtual reality is set to be a pillar of our everyday lives.
What is Virtual Reality?
A realistic three-dimensional image or artificial environment that is created with a mixture of interactive hardware and software, and presented to the user in such a way that the any doubts are suspended and it is accepted as a real environment in which it is interacted with in a seemingly real or physical way.
Key Elements of a Virtual Reality Experience
1. Virtual World: A virtual world is a three-dimensional environment that is often, but not necessarily, realized through a medium (i.e. rendering, display, etc.) where one can interact with others and create objects as part of that interaction.
2. Immersion: Virtual reality immersion is the perception of being physically present in a non-physical world. It encompasses the sense of presence, which is the point where the human brain believes that is somewhere it is really not, and is accomplished through purely mental and/or physical means.
3. Sensory Feedback: Virtual reality requires as many of our senses as possible to be simulated. These senses include vision (visual), hearing (aural), touch (haptic), and more. Properly stimulating these sense requires sensory feedback, which is achieved through integrated hardware and software (also known as inputs).
4. Interactivity: The element of interaction is crucial for virtual reality experiences to provide users with enough comfort to naturally engage with the virtual environment. If the virtual environment responds to a user’s action in a natural manner, excitement and senses of immersion will remain. If the virtual environment cannot respond quick enough, the human brain will quickly notice and the sense of immersion will diminish.
Types of Virtual Reality
Several categories of virtual reality technologies exist, with more likely to emerge as this technology progresses. The various types of virtual reality differ in their levels of immersion
Non-immersive simulations are the least immersive implementation of virtual reality technology. In a non-immersive simulation, only a subset of the user’s senses are stimulated, allowing for peripheral awareness of the reality outside the virtual reality simulation. Users enter into these three-dimensional virtual environments through a portal or window by utilising standard high resolution monitors powered by processing power typically found on conventional desktop workstations.
Semi-immersive simulations provide a more immersive experience, in which the user is partly but not fully immersed in a virtual environment. Semi-immersive simulations closely resemble and utilize many of the same technologies found in flight simulation. Semi-immersive simulations are powered by high performance graphical computing systems, which are often then coupled with large screen projector systems or multiple television projection systems to properly stimulate the user’s visuals.
Fully-immersive simulations provide the most immersive implementation of virtual reality technology. In a fully-immersive simulation, hardware such as head-mounted displays and motion detecting devices are used to stimulate all of a user’s senses. Fully immersive simulations are able to provide very realistic user experiences by delivering a wide field of view, high resolutions, increased update rates (also called refresh rate), and high levels of contrast into a user’s head-mounted display (HMD).
How Does Virtual Reality Work?
In order for the human brain to accept an artificial, virtual environment as real, it has to not only look real, but also feel real. Looking real can be achieved by wearing a head-mounted display (HMD) that displays a recreated life size, 3D virtual environment without the boundaries usually seen on TV or a computer screen. Feeling real can be achieved through handheld input devices such as motion trackers that base interactivity on the user’s movements. By stimulating many of the same senses one would use to navigate in the real world, virtual reality environments are feeling increasingly more like the natural world. Below, we explore some of the key components to behind this system.
Key Elements of a Virtual Reality Experience
PC (Personal Computer)/Console/Smartphone: Virtual reality content, which is the what users view inside of a virtual reality headset, is equally important as the headset itself. In order to power these interactive three-dimensional environments, significant computing power is required. This is where PC (Personal Computer), consoles, and smartphones come in. They act as the engine to power the content being produced.
Head-Mounted Display: A head-mounted display (also called HMD, Headset, or Goggles) is a type of device that contains a display mounted in front of a user’s eyes. This display usually covers the user’s full field of view and displays virtual reality content. Some virtual reality head mounted displays utilize smartphone displays, including the Google Cardboard or Samsung Gear VR. Head-mounted displays are often also accompanied with a headset to provide for audio stimulation.
Input Devices: Input devices are one of the two categories of components that provide users with a sense of immersion (i.e. convincing the human brain to accept an artificial environment as real). They provide users with a more natural way to navigate and interact within a virtual reality environment. Some of the more common forms of virtual reality input devices include: Joysticks, Force Balls/Tracking Balls, Controller, Wands, Data Gloves, Trackpads, On-Device Control Buttons, Motion Trackers/Bodysuits, Treadmills, Motion Platforms (Virtuix Omni)
How Virtual Reality Headsets Work
Sensors The three most common sensors in a virtual reality headset are magnetometers, accelerometers and gyroscopes. These sensors work together by measuring the user’s motions and direction in space. Their ultimate goal is to achieve true six-degrees-of-freedom (6DoF), which covers all the degrees of motion for an object in space.
Magnetometer – The magnetometer tells your device which direction it is facing on the surface of the earth. The magnetometer acts as a sort of compass for the device. As such, it is able to do this by measuring magnetic fields.
Accelerometers – The accelerometer tells your device which way up it is. To do this, your device will have several accelerometers to work together measuring things like gravitational pull in relation the accelerometer measuring the device’s orientation.
Gyroscopes – A gyroscope calculates the orientation of your device. It does this to either help your device maintain a particular orientation or make sure it properly changes orientation when it should.
Tracking handles the vital task of understanding a user’s movements and then acting upon them accordingly to maintain full immersion in virtual reality. Below, we explore the three of the main types of virtual reality tracking: Head tracking utilizes a series of sensors, vital to any virtual reality headset, which includes a gyroscope, accelerometer, and magnetometer.
Motion tracking is the way in which you view and interact with your own body (e.g. hands, movements, etc). One of the most natural motion-related acts is to want to be able to see your own hands (virtually) in front of you. To do this, virtual reality input accessories such as gloves can be used.
Eye tracking technology is still maturing, however, it may be one of the most important missing pieces to complete the virtual reality full immersion puzzle. Eye tracking involves tracking the human eyes via an infrared sensor that monitors your eye movement inside the headset. The main advantage to this type of tracking is that depth of field (i.e. distance) becomes much more realistic.