This page provides information on the Scene Assembly attribute that can be added to alembic meshes.
Overview
V-Ray's Scene Assembly attribute enables proxy representation rendering, when an alembic file is used in Maya's Assembly Definition.
UI Path
||Select mesh|| > Attribute Editor > Attributes menu > VRay > Scene Assembly
Attributes
GPU Cache Shader – An input for the alembic mesh material. Connect a material in the GPU Cache Shader slot to assign it to the proxy representation.
Not assigning a material to the alembic mesh through the GPU Cache Shader input results in no visual representation of the alembic mesh in the render.