Ray traced shadows

I would like to know if there is a way of implementing ray traced shadows described in this article:

I am sure that it can be coded but i am interested in a blueprint implementation. Can it be done?
Is someone interested in developing such a system? Or helping me BP this?

My idea so far is to do a line trace per pixel in the direction of the main lightsource (sun). The outcome (probably an array converted to an image) will be used as a mask for the light pass and then blended with the diffuse pass.

There are some issues with this, obviously. First is transparency and one solution would be to do a hybrid implementation where transparency is done the old fashioned way (shadow maps) and fully opaque objects are line traced.
Another issue is performance, so what i was thinking is doing traces just for the edges of the objects.

If this seems like a random rambling of a noob, well it kinda is. I just wanted to get a discussion going so that i can poke the minds of people much more competent than i am.

If you can shed some light (pun intended) on this or know someone that is working on something similar, please feel free to chip in.