its not entirely straightforward - conventionally you'd use bitwise operators for this sort of stuff. here's a link to get you started https://gamedev.stackexchange.com/questions/7859/hlsl-pack-4-values-into-32-bit-float I'm fairly confident it can be done in substance designer - it doesn't have bitwise operations but…
What's been done in this shader is unconventional and tbh looks a bit masturbatory Personally I'd have taken the sss and roughness out, compressed them as a 2 channel texture and halved the size if I was desperate to save memory. if the cost of one extra texture read per tree material is causing you problems then I'd…