Rt
From BRL-CAD
The rt command is the primary ray-tracer in BRL-CAD. The rt command can generate a variety of visualizations for a given BRL-CAD geometry database model depending on the selected lighting model and options used. The rt command can be invoked both on the command-line and on the mged command-line and is the default ray-tracer specified in MGED saveview scripts and Tools->Raytrace renderings.
