[MUSIC] Walk-in-place is another way to navigate in VR and it sits right in-between physical and virtual navigation. This method encourages the user to engage their whole body in the realistic walking motion as much as possible, but without actually moving forward. Users would literally be instructed to walk in place. Users should still be able to explore the virtual environment with their body, like bending their body to look underneath the table. But they should also be able to walk in the virtual environment by mimicking the walking motion without physically moving forward. The technical implementation could vary, but in most cases, head rotation data is used to define the direction of traveling, which is quite straightforward. The less straightforward part is to determine the speed of traveling, or simply whether the user is indeed walking or not. The very first paper which proposed this method in 1995 used a setup where only the position of head tracking is used to determine whether the user is walking or not. They used a machine learning algorithm to learn features from head position tracking while the user is moving or not moving. And with a large training data set, they were able to predict whether the user is walking. You can also use other types of tracking data, for instance head rotation or a hand position, or a combination of these to determine the speed of travel. For instance, the beauty in accelerometer and durometer which tracks the orientation could also be used to measure inertia, which can be used to determine speed. Other users can be moving their hands back and forth to mimic our arm movements when walking, and how quickly they move their hands can be used to indicate speed. One thing worth noting is that in both real walking and redirected walking there is no need to give instructions to the user of how to walk. They just walk the way they do, or at least the way they think they do. They don't need to learn how to use these interfaces. With Walk-in-place and all methods in virtual navigation, it is necessary to explain to the user how the specific method works, and ideally have a small training session where you let them have a test run until they fully get the idea. You should only let your users start the real VR experience or a game after this training session. As a developer, things that are obvious to you might not be so obvious to your user. [MUSIC]