Occlusion mask

Hello everyone,

Is it possible only through the material editor to get a result like this?

Or will I have to make custom shaders and scripts?

Taking a closer look, the effect also removes the shadow of the occluder, that I would not like to happen. i want just to see throgh the mesh so I can see my character.

I am pretty sure you can accomplish this using the current material graph editor by setting transparency of the objects around the player to 0 and using cutout mode (for performance). Shadows might be removed so you will need to ensure the shader still writes to the shadowmaps though (or not use alpha clip but I strongely advise against that due to performance reasons).