A new open source, portable, and scalable 3D visualization standard is in the works. Announced by Khronos Group ANARI (Analytic Rendering Interface) 1.0 Provisional Specification for scientific visualization and scalable 3D Data visualization. ANARI will enable users to quickly and easily build a scene description and create 3D images. Most importantly, ANARI doesn’t specify the rendering details; the rendering gets left to the backend engine which provides a simplified way to develop a visualization application with cross-vendor portability including ray tracing. From the announcement:

"The scientific visualization ecosystem includes key visualization application vendors such as VMD, VTK/ParaView, and VisIt that have actively participated in ANARI’s design. There are also early ANARI implementations in development by AMD, Intel and NVIDIA that will provide access to their Radeon ProRender, OSPRay, and VisRTX rendering engines respectively".

The specification is provisional and a full version 1 should be released soon (there is an open SDK available). There is also a good (and short) Overview Video that explains the benefits of ANARI.