there’s this now
it looks a thousand times better, but you also control over the buffers. for instance if you use roughness even a resolution of 32x32px will work, this reduces the impact by a lot. you can see it by clicking the “meshPhysical” toggle in that codesandbox linked in the tweet, look at the time per frame these two materials need to render. MTM takes like 0.2ms on my system, MPM is consistently over 2ms, this i think is due to the smaller buffer.
you find the vanilla material here MeshTransmissionMaterial: more realistic glas/epoxy/gelatin - #11 by drcmda although that one has the same issue as MPM, you would have to use the one from drei.