Point Particle

The V-Ray Point Particle material is specifically designed for rendering particles coming from Alembic or .vrmesh files when Particle render mode in the V-Ray Proxy object is set to Points. 

Diffuse Color - The diffuse color of the material.

Phase Function - Determines the general way light scatters inside the material through a value between -1.0 and 1.0. Its effect can be somewhat likened to the difference between diffuse and glossy reflections from a surface, however the phase function controls the reflection and transmittance of a volume. A value of 0.0 means that light scatters uniformly in all directions (isotropic scattering); positive values mean that light scatters predominantly forward in the same direction as it comes from; negative values mean that light scatters mostly backward. Most water-based materials (e.g. skin, milk) exhibit strong forward scattering, while hard materials like marble exhibit backward scattering. This parameter affects most strongly the single scattering component of the material. Positive values reduce the visible effect of single scattering component, while negative values make the single scattering component generally more prominent.

Use Particle Color - Enable to render the Particle Color instead of the diffuse color.