When the user's cursor hovers over a bookmark, a preview of the point of view is displayed to the user, and when the user clicks on a bookmark, the camera smoothly moves from its current position to the bookmarked point of view.
We conduct a within-subject user-study on 51 participants, where each user starts with a tutorial to get used to the 3D navigation controls, and then tries successively to perform a task with and without bookmarks.
We show that not only the presence of bookmarks causes a faster task completion, but also that it allows users to see a larger part of the scene during the same time span.
However, in a streaming scenario, this phenomenon leads to higher network requirements to maintain the same quality of service\todo{not sure if service or experience}.
In the last part of this chapter, we simulate streaming by replaying the traces collected during the user study, and we show that knowing the positions of the bookmarks beforehand allows us to pre-compute information that we can reuse during streaming to compensate for the harm caused by the faster navigation with bookmarks.
