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\section{Introduction}

In Chapter~\ref{bi}, we described how it is possible to modify a user interface to ease user navigation in a 3D scene, and how the system can benefit from it.
In Chapter~\ref{d3}, we presented the DASH-3D streaming system, which does not depend on the interface nor on the user interaction. 
In this chapter, we will analyze how the user interaction can impact performances of DASH-3D.
In order to do so, we followed these two steps:

\begin{itemize}
    \item we design an interface allowing to navigate in a 3D scene on both desktop and mobile devices;
    \item we improve and adapt the bookmarks described in Chapter~\ref{bi} to the context of DASH-3D and to mobile interaction.
\end{itemize}

In Section~\ref{sb:interaction}, we present the different choices we made for the interfaces, and we describe the new mobile interface.
In Section~\ref{sb:bookmarks}, we describe how we embed the bookmarks into our DASH framework, and how we precompute data in order to improve the user quality of experience.
In Section~\ref{sb:evaluation}, we describe the user study we conducted, the data we collected and we analyse the results.
