SbDPViewVolume(3) on Linux
The text ec8d1d64224e, as Debian 6.0 (Squeeze) shipped it.
The SbDPViewVolume class is a double precision viewing volume in 3D space. This class contains the necessary information for storing a view volume. It has methods for projection of primitives from or into the 3D volume, doing camera transforms, view volume transforms etc.