{"id":574614,"date":"2019-03-22T12:58:33","date_gmt":"2019-03-22T19:58:33","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/research\/?p=574614"},"modified":"2019-05-31T16:29:14","modified_gmt":"2019-05-31T23:29:14","slug":"giant-steps-and-liberating-spaces-virtual-reality-is-making-cool-moves","status":"publish","type":"post","link":"https:\/\/www.microsoft.com\/en-us\/research\/blog\/giant-steps-and-liberating-spaces-virtual-reality-is-making-cool-moves\/","title":{"rendered":"Giant steps and liberating spaces \u2013 Virtual Reality is making cool moves"},"content":{"rendered":"

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Cool innovations are happening in how virtual reality researchers are resolving natural locomotion challenges and how they relate to story space, as well as in liberating users from the small, object-free player settings of today, to allow them to safely roam the real world.<\/p>\n

Virtual Reality (VR) has become familiar to many people in past years. Users can put on a head-mounted display (HMD) and immediately be transferred to an imaginary world where everything they see and hear has been authored to engulf them in an immersive experience. Until recently, tracking technologies in VR required the user to remain within a room where sensors could track their location and movement. Furthermore, all physical obstacles had to be removed from this assigned space in order to assure the safety of the user who is blind to the physical world.<\/p>\n

These restrictions required every virtual world displayed to be mapped to the same room. While non-immersive video games might move the player around the game world, doing the same in VR can generate motion sickness. When visual motion disagrees with lack of vestibular stimulation there is motion sickness. Designers of virtual experiences had resorted to imaginative\u2014and sometimes quite unnatural\u2014ways to virtually move the user while remaining confined in the room, such as teleportation to new locations (opens in new tab)<\/span><\/a>, walking in place (opens in new tab)<\/span><\/a> and moving using hand motions.<\/p>\n

Compressing distances by enlarging the user<\/h3>\n

In a new work to appear at CHI 2019<\/a>, Microsoft researchers, Mar Gonzalez-Franco<\/a>, Eyal Ofek<\/a> with collaboration with Professor Anthony Steed of UCL and Parastoo Abtahi of Stanford University, looked at different methods to improve natural locomotion in VR. One way they hit upon to overcome the space limitations was to change the scales of space or motion. Researchers found inspiration in famous fairy tales such as Alice in Wonderland and Seven-League Boots that led to innovative navigation techniques (see Figure 1) that would allow a whole world to be compressed and users able to visit a whole city by walking around their living room.<\/p>\n

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Figure 1: I\u2019m a giant. By scaling down the city the user can walk naturally, while every step is 10x larger relative to the city. The sensation is as if the user is a giant Gulliver waking in a Lilliputian world.<\/p><\/div>\n

To achieve super-speed gains when a user walks in the virtual world, steps are stretched following a known technique called Seven-League Boots (opens in new tab)<\/span><\/a>. This way, users feel as if the virtual world flies around them fast, as they move at a natural pace. However, the researchers realized that under large speeding factors (greater than 3x), they would start to lose control of the motion and overshoot, slowing up the locomotion process and increasing the user\u2019s frustrations.<\/p>\n

Instead of speeding, the researchers then also looked at scaling the users size relative to the virtual world (see Figure 2, center panel.) In contrast to the speed gain method, this technique uses a 1:1 mapping between the user\u2019s motion and the virtual avatar, enabling natural control even when the scale change is as big as 30x. Users, walking in a smaller environment, look down as though they are a giant surveying a toy city. Such a point of view might be great for traveling between large landmarks, however the distance to the environment makes it hard for the user to detect small details, such as identifying a specific door down a road. A second method, eye-level scaling, shrinks the world around the user\u2019s head, generating the impression that the user\u2019s view is positioned at a height of a normal person in the virtual world. While visible motion looks fast relative to the small world, it maintains natural control and enables a natural view of the world ground level details.<\/p>\n

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Figure 2: The virtual city as seen by a user walking in its main street at a regular scale (left). The user walking down the same street while scaled to a giant (center). When researchers maintained the user\u2019s point of view at ground level, users achieved a natural fast motion with good control.<\/p><\/div>\n

Once the user arrives at their destination and wants to go through the door of VR wonderland, they can be scaled back to 1:1.<\/p>\n

This form of locomotion for virtual reality experiences has many advantages. It is natural and requires no training, increases immersivity (compared to teleportation), and it avoids motion sickness.<\/p>\n\t