Simple cloud modeled with openvdb toolset, which i am implementing in ICE. rendered in arnold, image is noisy to gain reasonable times ( ~22 sec per frame 720p ) youtube.com/watch?v=0OlSnAm69x4
If you like to learn more about openvdb features, see this presentation for example:
Thanks to Steven Caron for helping with arnold and initial vdb plugin for softimage
Openvdb is efficient voxel strorage format which i believe is already became the standard for industry like alembic.