Translucency/Subsurface question, show a shape inside a box

[Cgi_Layers]

Hello everyone ^^
I’m tring to recreate an effect in UE5 (5.4 or 5.5 bc I need a plugin that only works on those versions) and would love to get some general direction or tips/tricks to help me get closer to i.

The idea is to make a subsurface material, apply it on a box/cube and when it gets lit from the back you should be able to see a shape inside the box.
The closes I’ve managed to get can be seen in the screenshot, the left one is a projection of the shadow on a SSS material, the right one is a thickness mask. As you can see in both cases the final result is only a 2D shape visible only from one side, what I need is to be able to rotate a light around it and be able to see the shape.

Thank you beforehand!

[Cgi_Layers]

Managed to get this by using substrate, and combining 3 meshes in the same spot, one with the opacity (TranslucentColoredTransmitance - surface tranlucency volume) one controlls the blurry tranlucency (TranslucentColoredTransmitance - Surface Forward shadowing) and one last mesh with invierted normals and SSS. Then inside the mesh is simply a black unlit material.