SbSpherePlaneProjector(3) on Linux
The text 933c77b7b19b, as Debian 6.0 (Squeeze) shipped it.
The SbSpherePlaneProjector class projects 2D points to a half-sphere and a plane. This projector uses a plane along with the half-sphere of SbSphereSectionProjector for projections. If the 2D point mapping 'misses' the sphere section, the 3D point will be projected onto the plane.