How to create a custom box with ShaderMaterial?

Questions
1

I want to create a box with code, the box like this:

custom_box

The cuboid satisfies the following conditions:

  1. the border width is 2
  2. the transparency of the back faces is 0.8, and that of the other faces is 0.2;

I tried to use LineSegments, but it didn’t meet my requirements.

I guess I may need to use ShaderMaterial, but I don’t know how to write it at the moment.

2

Well, my question is wrong.
The second parameter of Mesh can be an array of Material.

const normal_face_material = new MeshBasicMaterial({
    color: 'red',
    transparent: true,
    opacity: 0.2,
})

const special_face_material = normal_face_material.clone()
special_face_material.opacity = 0.8
special_face_material.side = DoubleSide

const box = new Mesh(
    new BoxGeometry(width, height, depth),
    [special_face_material, normal_face_material, normal_face_material, normal_face_material, normal_face_material, normal_face_material]
)

It can also simplify the code

- [special_face_material, normal_face_material, normal_face_material, normal_face_material, normal_face_material, normal_face_material]
+ [special_face_material].concat( new Array(5).fill(normal_face_material) )