A software program called Denizen was used to create over 700 distinctive characters[46] that populate the city,[50] while a new rendering system called Hyperion offered new illumination possibilities, like light shining through a translucent object (i.e., Baymax's vinyl covering).[51] Development on Hyperion started in 2011 and was based upon research into multi-bounce complex global illumination originally conducted at Disney Research in Zürich.[46] Disney in turn had to assemble a new supercomputing cluster just to handle Hyperion's immense processing demands, which consists of over 2,300 Linux workstations distributed across four data centers (three in Los Angeles and one in San Francisco).[46] Each workstation, as of 2014, included a pair of 2.4GHz Intel Xeon processors, 256 GB of memory, and a pair of 300 GB solid-state drives configured as a RAID Level 0 array (i.e., to operate as a single 600 GB single drive).[46] This was all backed by a central storage system with a capacity of five petabytes, which holds all digital assets as well as archival copies of all 54 Disney Animation films.[46]