LuxRays is a raytracing library, that belongs to LuxRender project. I'm the maintainer of graphics/luxrays ports, but as far as I know LuxRender is the only application using LuxRays (and there is currently no existing or proposed port depending on graphics/luxrays). I filed the port only to help with updating graphics/luxrender. Moreover since then the maintainer of graphics/luxrender updated it, with LuxRays bundled in. On top of that, the point of LuxRays is mostly providing a ray-oriented high-level interface to OpenCL. OpenCL support in FreeBSD isn't stellar, so even if there was some obscure application needing graphics/luxrays, it wouldn't be that useful. So I believe the best course of action is to remove graphics/luxrays and leave graphics/luxrender with its bundled copy.
I will deprecate it for removal (say 15 august)
A commit references this bug: Author: marino Date: Fri Jul 11 21:11:13 UTC 2014 New revision: 361585 URL: http://svnweb.freebsd.org/changeset/ports/361585 Log: graphics/luxrays: Deprecate; luxrender now bundles it The only known purpose for luxrays is as a dependency for luxrender, but now luxrender comes with its own bundled version of luxrays. In the opinion of the maintainer, luxrays is not useful for anything else and recommends that the port be retired (scheduled for 15 Aug 2014) PR: 191658 Submitted by: maintainer (Natacha Porte) Approved by: portmgr (implicit, NOT_STAGED) Changes: head/graphics/luxrays/Makefile