This is actually the cabin of the shower, not the shower itself.
The bottom and back plate are made from wood. There is some margin in the bottom plane, to ensure that the door has space for movement.
Doors and side panels are made from 2mm acrylic plate, to give a nice glassy look.
You can simply glue everything together after milling it, and it looks just fine. I decided to make my door move, which is a bit more of a pain... There are a few ways to solve this. I decided to make a profile at the top from metal can, folded in such a way that the door can slide through it.
However, every millimeter here counts, and I'm in doubt to change this into something more precise. You can make a (aluminium or wooden) profile at the top, basically a mirror from the bottom plate. without the center piece. That way, the bottom and top are exactly the same, and the door will move perfectly.
You can find the cloud 3D model here, or download the F3D file from the repository.