3DNSITE: a networked interactive 3D visualization system to simplify location awareness in crisis management

We report on the 3DNSITE system, a web-based client-server 3D visualization tool for streaming and visualizing large tridimensional hybrid data (georeferenced point clouds and photographs with associated viewpoints and camera parameters). The system is motivated by the need to simplify data acquisition and location recognition for crisis managers and first responders during emergency operations or training sessions. In this peculiar context, it is very important to easily share 3D environment data among people in a distributed environment, accessing huge 3D models with embedded photographs on devices with heterogenous hardware capabilities and interconnected on different network types. Moreover, since the specific end-users are not necessary skilled with virtual reality and 3D objects interaction, the navigation interface must be simple and intuitive. Taking into account these constraints, we propose a mixel object-based/image-based system, which enhances the current state-of-the-art by exploiting a multi-resolution representation for the 3D model and a multi-level cache system for both the images and 3D models structure. A novel low-degree-of-freedom user interface is presented to navigate in the scenario with touchscreen devices. The proposed implementation, included in a more general training and decision framework for emergency operations, is evaluated on real-world datasets.