This page provides information on the V-Ray PhxShaderSim node.
V-Ray VolumeGrid Shader node works together with a volume object to produce a V-Ray Volume Grid. This node controls the rendering and shading properties of the volumetric cache. See the Volumetric Grid page for additional information on how to set up a V-Ray Volume Grid.
When rendering volumetric effects with the Volume Grid Shader, please use the VDB file format for caching the simulation to disk. Houdini's native volumes are supported, however, those are always baked to the VRScene instead of referenced from disk.
The Field tab on the VolumeGrid Shader, expects vector fields to be represented as three separate float fields. E.g. vel should be vel.x, vel.y, and vel.z when you middle-click on the node holding the volumes. The same goes for Cd and for rendering the native Houdini volumes. Technically speaking, there is no requirement to convert them to VDBs and cache them to a disk, but it makes things more efficient. Otherwise, the entire volume is baked to the VRScene file instead of being read from a disk.
||mat Network|| > V-Ray > Volume > V-Ray VolumeGrid Shader
The V-Ray VolumeGrid Shader divides its parameters into several tabs:
The V-Ray VolumeGrid Shader also provides several rendering presets for specific types of simulations. They are accessible through the gear icon: