[MUSIC] One of the most basic VR interactions is the user's ability to move around, and explore the virtual environment. There are different ways you can design navigation in VR, depending on what you want the users to do. They might not need to move that much if they're watching a football match, especially if they're already sitting in the best seat. If they're doing sports, such as playing ping pong in VR, then they should be able to use their body as naturally as possible, but within a relatively small area, this can be simply supported by. Or if you want to use this to be able to explore a larger space, something bigger than the physical space they're actually in. For instance, they might want to walk around and view the space in the 3D model of a house before it's built. Then you will have to be a bit more creative. We will introduce a few methods for you to consider in this situation. The user's ability to navigate in VR is also restricted by the VR system they're using. High end VR is supported by a desktop or laptop. It usually comes with position tracking of the headset. This allow the users to explore the environment in a naturalistic way, as the graphics in the virtual world will just update according to the physical position detected by the tracking system. So high end VR with precision tracking supports physical navigation, where the users physical motion is used to transport a user through the virtual world. With most mobile VR system where the precision tracking is not supported, we're physically kind of stuck in a fixed point in the virtual world. So we can't bend our body to see what's underneath the table. And we can't walk up to an object to observe it up close. In other words, due to that limitation in tracking, our physical movement cannot be fully captured and translated into the virtual world. But it does not mean that we can't move in the virtual world. We just need to find other ways to tell our mobile phone which renders VR that we want to move. The most common way of doing this is to borrow what we do when playing games on the 2D screen. Where we normally navigate the environment using a patchpad or a joystick. This is normally called virtual navigation. With this method, users are no longer restricted by the physical space they're in, and their body remains stationary even though the viewpoint moves. But it is less natural, and it's more likely to cause simulation sickness. Both physical navigation and virtual navigation have their pros and cons. And in many cases, some hybrid methods are used to benefit from both. In the rest of this week, we'll explain a couple of different methods developed in the past few decades, in VR research. [MUSIC]