this track comes close to the track clew.
sr has only a very few tracks with opened pipes
and i have some small ideas
the first one is a road-material transion like you have it with pipes (0% - no pipes/material a, 50% opened pipe/both materials mixed, 100% closed pipe/material b)
the second one isa pipe that uses two materials (like a opened pipe with a non-glass material with a turned opened glass-pipe on the other pipe, no transition between both materials)