Arnold for Maya (or MtoA) provides a bridge to the Arnold renderer from within Maya’s standard interface. MtoA is now shipping with the Arnold 5.0 core.
-Seamless integration with Maya shapes, cameras, lights and shaders.
-Image Based Lighting support, including a state of the art physical sky.
-Interactive rendering (IPR) allows parameter changes to be rapidly previewed without interrupting your work.
-Support for volume rendering with Maya Fluids.
-Support for Maya Hair and nHair.
-Particles and nParticles support, including particle instancer.
-Defer the creation of geometry at render time with the Stand-in placeholder nodes.
-Productivity boost: override sets, holdout mattes, shadow catcher, passes, UDIM style textures, and arbitrary primvar data.
-Extensible through plug-ins (Golaem, FumeFX for Maya, Yeti, Shave & Haircut).
-Texturable geometric lights.
-Rendering of curves.