Here’s a new version of the abcimport shader that is compatible with mental ray 3.12 and mental ray for Maya 2015. It can be downloaded from this link. The package contains a version for Windows, Linux and Mac OS X, as well as the .mi file with the new shader declaration.

The new features:

• Support for hair import
  Alembic curve objects are translated into mental ray hair geometry. The curves can be defined with linear segments, quadratic bezier and cubic b-spline (either uniform or with given knot vector). Hair approximation quality can be set with the shader parameter “subdivisions”  (default 0). The parameter controls the number of subdivisions for hair segments. The picture shows a rendering of an Alembic file generated by Ornatrix 3, with linear hair segments and using the shader “mib_illum_hair_x”.                                                                         Hair alembic file courtesy Ephere Inc
• Faceset material support
  In Maya, the facesets are assigned with material names. Our abcimport shader now uses this information to reference materials with these names. Facesets can be either triangle or polygon mesh. (Facesets for subdivision surfaces will be added later.) Faceset translation is enabled by default and can be turned off by setting the shader parameter “facesetmaterials” to off.
• User data support
  Triangle meshes now can reference user data such as color3, color4, point, normal, float, integer. The user data must be attached as “arbitrary geometry parameter property” to objects in the abc file. Please, contact us for more details.
• Subdivision control for hair, NURBS and subdivision surfaces
  The “subdivision” parameter is now also applied to hair, NURBS trim curves, NURBS, and subdivision surfaces.
• Motion blur issues fixed
  Motion blur for topology changing abc files is now possible. We fixed an issue with the velocities in Alembic which were not interpreted correctly.

These features will be incorporated into the upcoming versions of mental ray this year.