SbSpherePlaneProjector(3) on Linux
The text 3c52e38a7c90, as Debian 8 (Jessie) 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.