This was all done by editing existing CVEX node based shaders!Īs in Dead Island, we again lit the Hair using volumetric shadow casting proxies, which provided a good representation of the hair shape and density. This is an extensively modified version of the already flexible system provided out-of-the-box in Houdini that contains many enhancements such as curling, noises, and most importantly a new guide following method which is much better suited to controlling long styled human hair. For longer hair, we have continued to use and develop the system that we previously used in our Dead Island trailer. Sergio Caires: The buzz cuts were a creative choice motivated by the military theme of the series. Can you tell us a little more about the process involved generating this hair? SideFX: The hair on the Spartan characters looks fantastic, and like everything else, incredibly real. The new instancing system was of the utmost importance to us when rendering a highly detailed armoury in Spartan Ops Episode 1, in the shot where the Spartans get suited up - those Gyro Bays were very complex objects. The latest geo core rebuild in H12 really was perfect timing for us to be able to handle such massive amounts of data. Houdini is open enough that we could even use CVEX to modify our geometry cache data through the delayed load at render time.
The integration of our own custom render time delayed load procedural, which loads cache data directly from our animation software Maya, was completely seamless. These assets were built with user-editable artist areas allowing for procedural modification for both pre and post deformation. Our asset system was able to generate the Houdini assets automatically, along with the shader templates all hooked together with Houdini’s Digital Assets. For Spartan Ops, we rebuilt our asset system in Houdini to make it as automated as possible. Nicholas Pliatsikas: The flexibility that Houdini gave us was paramount because we had a huge amount of assets in place that created large volumes of file I/O. He built us an amazingly detailed looking model with around 26 million polygons that we completed with Mantra at an amazing success rate! He asked us the question "what is your polygon budget?" and I replied with words to the effect of "go nuts on it". In Halo 4, there is a model of a spacecraft called the Infinity that was created by Ansel Hsiao, a spaceship modeling god. Its reliability and robustness gives us supreme confidence in its ability. Sergio Caires: We have not come across any renderer (and we have been through a few big ones) that can handle anything like the amount of data that we push through Mantra so effortlessly - and then have the audacity to raytrace against it. How well did Mantra perform when handling large volumes of data? SideFX: Halo 4 Spartan Ops was surely a data intensive project with its incredible realism. You would now struggle to find a project on our website that wasn't rendered in Mantra. Sergio Caires: Yes it is and has been for a long time. SideFX: Is it true that Mantra has become your ‘go-to’ renderer for all of your projects?