Efficient 3D Reconstruction and Streaming for GroupScale Multiclient Live Telepresence Sharing live telepresence experiences for teleconferencing or remote collaboration receives increasing interest with the recent progress in capturing and ARVR technology. Whereas impressive telepresence systems have been proposed on top of onthefly scene capture, data transmission and visualization, these systems are restricted to the immersion of single or up to a low number of users into the respective scenarios. In this paper, we direct our attention on immersing significantly larger groups of people into livecaptured scenes as required in education, entertainment or collaboration scenarios. For this purpose, rather than abandoning previous approaches, we present a range of optimizations of the involved reconstruction and streaming components that allow the immersion of a group of more than 24 users within the same scene  which is about a factor of 6 higher than in previous work  without introducing further latency or changing the involved consumer hardware setup. We demonstrate that our optimized system is capable of generating highquality scene reconstructions as well as providing an immersive viewing experience to a large group of people within these livecaptured scenes.

A VR System for Immersive Teleoperation and Live Exploration with a Mobile Robot Applications like disaster management and industrial inspection often require experts to enter contaminated places. To circumvent the need for physical presence, it is desirable to generate a fully immersive individual live teleoperation experience. However, standard videobased approaches suffer from a limited degree of immersion and situation awareness due to the restriction to the camera view, which impacts the navigation. In this paper, we present a novel VRbased practical system for immersive robot teleoperation and scene exploration. While being operated through the scene, a robot captures RGBD data that is streamed to a SLAMbased live multiclient telepresence system. Here, a global 3D model of the already captured scene parts is reconstructed and streamed to the individual remote user clients where the rendering for e.g. headmounted display devices (HMDs) is performed. We introduce a novel lightweight robot client component which transmits robotspecific data and enables a quick integration into existing robotic systems. This way, in contrast to first person exploration systems, the operators can explore and navigate in the remote site completely independent of the current position and view of the capturing robot, complementing traditional input devices for teleoperation. We provide a proofofconcept implementation and demonstrate the capabilities as well as the performance of our system regarding interactive object measurements and bandwidthefficient data streaming and visualization. Furthermore, we show its benefits over purely videobased teleoperation in a user study revealing a higher degree of situation awareness and a more precise navigation in challenging environments.