Nah sure it isn’t free but I mean this is how Nintendo made metal Mario on the N64. I’d argue the majority of glass in games use opaque materials cubemapping in for fake transparency, or even more expensive tricks like parallax environment mapping. All of these techniques are still pretty much universally cheaper than translucent while integrating into the lighting much better.
UE5 transparency is pretty compromised unless you enable tons of extra cost features like high quality translucent reflections and order independent transparency.
I’m actually surprised when I see a true transparent shader in a game for glass instead of opaque fakery. Usually only because it is relevant for gameplay (such as windows you can shoot through).
God of War Ragnarok: Bottles are using fake transparency with cubemaps.
Half Life Alyx: cubemaps.
Dying Light 2: Despite being an RT heavy title, car and bus windows are opaque fake transparency with parallax. Even the glass on light fixtures is fake parallax offset shader tricks.
Almost every non-breakable window in every game ever, opaque, dirty and maybe a bit of parallax trickery that has been common since the early 2010s. BioShock Inf., CS2, Spiderman…
Last of Us: most water and glass are cubemaps except breakable windows.
I could go on.
I think something noteworthy is all of these games received significant praise for their their visuals and those who noticed the tricks often feel impressed rather than decieved.
But I do look forward to the day pathtracing is the norm and we can leave all this nonsense behind for most cases.