The Ignite Distributed Collaborative Scientific Visualization System
Many scientific projects involve visualizations of very large data sets. For this reason, the NSF and other agencies have developed a number of high-end visualization systems, notably the CAVE and the OptIPuter. Since experts are distributed and want to interact with the visualization and with each other through the data, a number of these systems have been designed for collaborative interaction, featuring very high-bandwidth specialized networks. These systems and the networks that support them are large and expensive; it doesn't come to your desktop, much less to your hand. The Ignite Distributed Collaborative Scientific Visualization System is a web-based interactive collaborative visualization system designed to be deployed on any device, and to interact with the user seamlessly, with data sets of any size. The combination of small devices with big data implies the need for a server infrastructure to render the data for the user; the requirement for seamless interaction forces a server to be near to any user. And in a collaborative system, the users can be anywhere; hence the servers must be everywhere.
The Ignite Distributed Collaborative Scientific Visualization System features a network of data servers with replicated data and computation at a number of sites throughout the United States, Western Europe and Japan, with visualizations served on identical Lively pages. We use Lively-2-Lively as an inter-page messaging system, which permits viewers of each page to see the actions of other users: a user pans across a map in Tokyo, and the map in Washington moves. Only view-change events are sent across the wire, with a specification of the view to be displayed in the remote location.
The Ignite Visualization System provides seamless interactionand immediate updates even under heavy load and when users are widely separated: the design goal was to fetch a data set consisting of 30,000 points from a server and render it within 150 milliseconds, for a user anywhere in the world, and reflect changes made by a user in one location to all other users within a bound provided by network latency. The system was demonstrated succesfully on a significant worldwide air pollution data set, with pollutionvalues on a 10km, 25km, 50km, and 100km worldwide grid, with monthly values over an 18-year period. It was demonstrated on a wide variety of clients, including laptop, tablet, and smartphone. We demonstrated it with eight users simultaneously connected and manipulating the map, with sites in Tokyo, Victoria, San Francisco, Washington, Ghent, and Potsdam.
This is a joint project of UVic, HPI, UT-Dallas, and CDG. Our plans are to extend this to other types of scientific data sets and visualizations.