From the Piranesi website:
Our EPix add-in lets you export a 3D view from Autodesk® Revit® Architecture to a Piranesi EPix file.
Piranesi 6 Pro is required. If you have Piranesi 2010, there’s a free upgrade. Upgrades from earlier versions can be purchased from our Piranesi Shop.
Add-in for Autodesk Revit Architecture 2011
Add-in for Autodesk Revit Architecture 2012
Add-in for Autodesk Revit Architecture 2013
Add-in for Autodesk Revit Architecture 2014
Add-in for Autodesk Revit Architecture 2015
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