This page provides some details on the settings available for the BSDFPointParticle material node.
Overview
The BSDFPointParticle material is specifically designed for rendering points when the Render Points As (Mantra) option in the Render tab > Geometry sub-tab is set to Circles.
UI Paths
||mat Network|| > V-Ray > Material > V-Ray Point Particle
||out Network|| > V-Ray Render Element node > V-Ray > Material > V-Ray Point Particle
Nodes
The BSDFPointParticle node provides inputs for controlling various material properties. They correspond to parameters in the section below.
Parameters
Diffuse Color – Specifies the color of the points.
Use Particle Color – When enabled, renders the point colors instead of using the diffuse color.
Phase Function – Specifies how light scatters from the point particles. A value of 0.0 means perfect diffuse scattering in all directions. Values close to 1.0 specify that light scatters predominantly in the direction that it comes from. A value close to -1.0 specifies that light scatters mostly backward. The phase function is useful to simulate scattering from water mist or steam, in which case values between 0.0 and 1.0 work best. For dust particles, smoke or soot, a value of 0.0 is more appropriate. The particular phase function model that is implemented is the Henyey-Greenstein model.
Example: The Effect of the Phase Function Parameter
In the images below, we have particles randomly distributed in a plane, with two spherical lights behind and in front of the plane. The images show how the particles scatter the light coming from the spherical lights depending on the phase function parameter.
The Phase Function is 0.0 and the particles scatter light uniformly.
This is characteristic for particles that form dust, smoke or soot.
The Phase Function is 0.8 and the particles scatter light predominantly forward.
This is characteristic for the way light is scattered from water droplets.
The Phase Function is -0.8 and the particles scatter light backward.
Notes
- If the material is applied to spherical particles or regular geometry, it will render as a normal diffuse material.