3rd Person Camera Shader? - Make Polys that Obscure the Character Translucent

How do I do this?

Is there already a script out there that does this or do I need a shader that makes obscuring polygons transparent?

Some objects in the game, like a spiral staircase, or a castle, is one large mesh. If this whole object become transparent, then the character would be walking on on a half visible staircase! This is unacceptable, so the way I see it I have to make a ton of small objects, or have a clever script that calculates what polygons to make transparent.

Is there a clever script that does this already out?

I think I can do this with a script that does a raytrace from the camera’s perspective toward the character, and access the object in front of him. But then can I find the material properties and add a transparency shader to just the obscuring polygons based on uv coords?.

Is there a script or some code someone could show me to help out?

Any input greatly appreciated, thanks!

Would some sort of projector fixed to the camera work? Get the projection information and route it through to the alpha of the shader of objects in the way of the player…

Or a screen UV coords texture (assuming the camera’s always fixed looking at the player)?