A tool called hdRstr by Stefan Krake provides impressive results in real-time.
The tool is developed as a Hydra render delegate supporting the main features of Pixar’s Universal Scene Description (USD). In Houdini, hdRstr can be used as part of a USD workflow (Hydra render delegates are only supported inside Solaris). As for Maya, it can be used as an alternative to Viewport 2.0. Please note that it currently only works on Windows.