(Only lighted parts of object visible, Shadows transparent) visible in viewport

[Adom25]

Hi everyone, here's a difficult one :

For a project I need to have only the lighted parts of an object visible. Everything that is not in the spot light should be transparent. And this particularity should be visible in the viewport.

Let's say I use a spotlight on a plan, I want only the part of the mesh in the circle of light to be opaque and everything out of it is transparent.

Please let me know if you have any ideas.

Thanks for your time

[Christoph_Schaedl]

If the object is highres you could try to use vertexcolors.