VRayVolumeGrid is a special kind of volumetric effect that works with grid-based cache formats, compared to Environment Fog which is a general purpose volumetric effect. The Volumetric Grid reads its data from an input file which supports grid-based representation of the volume.
Currently, VRayVolumeGrid supports three volume formats:
Fancy Bullets
type
circle
OpenVDB (.vdb ) - Supported by Houdini ® , FumeFX ® and RealFlow ®
Field3D (. f3d ) - Supported by FumeFX ® and Maya ® (using 3rd party plugins)
Immediately after the VRayVolumeGrid is created, a dialog appears for selecting the input file. After selection of the input file, a number of options are available to fine-tune and customize the volume.