Hyperion is Disney's proprietary inhouse renderer. The quesion I ask myself is: Well, they have a world class renderer in the company, called Renderman, so why develop a completly new renderer?
Hyperion first use in a complete animated features was in BigHero6. The intersting thing about Hyperion is that it does grouped an sorted ray batches. This way a lot of similar rays can be grouped together and make an more efficient usage of shading informations. It allows out of core rendering of geometry, that means it can render geometry which does not fit into ram, what have to be a huge amount of geometry with todays computers. It is a unidirectional pathtracer and with some quasi bidirectional tricks, they can efficiently render caustics, what in most unidirectional pathtracers is a problem. Of course they use mulitple importance sampling to reduce noise. Similiar to Animal Logics Glimpse, the renderer does not do spectral rendering because it is not needed at the moment.
Once again fxguide has a great article about Hyperion.
Disney itself has a very nice article about Hyperion and a interesting video about how pathtracing works.
Last update: 09.2016