Swimbladdered fish (SBF) object/class.

A S4 class that provides slots to contain relevant animal metadata for parameterizing models for swimbladdered fish (SBF) that are partitioned into two sets of discretized cylinders: the body and the swimbladder. Both shapes comprise independent position matrices, material properties, orientations, and other relevant shape-related data and metadata.See scatterer-class for a more detailed description on how this S4 object is organized.