Opacity mask Everything Behind

Hi

Currently i´m developing a game that revolves around visibility mechanics

While working on the prototype in UDK I have been looking for ways to make a dynamic mesh that is opacity masked to also mask the objects behind it.

To make my self clear, i made this demo in a compositing program (BMD Fusion), using the 3d renderer (opengl renderer)

and here is viewport example

So basically the mesh moving across has a material property called IsMatte

DemoForumUDK_Twinsg.gif

Reading the Fusion Manual to find the ways of how this is done, is explained that a “special texture is used”

Now, i am not specting a one button solution, but does any body know how can this be done in UE4?

Should I follow the path of the Custom Depth Buffer?

Or something like this

Perhaps gaining access to g buffers ???