Arnold for Maya (or MtoA) provides a bridge to the Arnold renderer from within Maya’s standard interface.

Features
– 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).
– XGen integration.
– Texturable geometric lights.
– Deep EXR.
– Rendering of curves.