How to use custom shape mask instead using BoxMask-3D

[Summilly]

I am using a BoxMask-3D to create a square shape see-through from a human body.

Using lineTrace dynamically see through any spot on this human body and the box size can be increased or decreased.

My question is - I want to make it look like knife wound shape instead a square, It will look like this shape, Is it possible to do this?

Material blueprint：

Thanks!