The Volume module allows to import and edit OpenVDB data.

VolumeObject represents a volume in a scene, see VolumeObject Manual.
VolumeBuilder is a scene object used to create volumes, see VolumeBuilder Manual.
VolumeSet is a scene object containing multiple volume objects, see VolumeSet Manual.
maxon::VolumeInterface defines a core volumes, see VolumeInterface Manual.
maxon::VolumeToolsInterface provides tools to handle volumes, see Volume Tools Manual.