Saw some posts 'bout the new Ray Portal BSDF shader node in 4.2.0 alpha, wanted to try it out:
Used build blender-4.2.0-alpha+main.02f2d73b78f4-windows. Store Transform and part of RayPortal.Material.000 copied from tv_scene_packed.blend by david494, see the pullreq. Please note that I don’t really know what I’m doing or why pretty much any of this worked, just playing around.