subsurface transparent material

Hi,

I am using a subsurface material on a lampshade, so that I get the light transmission from the bulb inside the lampshade to light the outside surface of the lampshade (one sided material). This works well, but it seems like I don’t have any control over the transparency of the material (opacity when in subsurface mode determines how much light scatters - according to the unreal docs).

What I am trying to achieve is to have some light shine through the lampshade and cast light onto the adjacent wall. Currently I get no light as the lampshade is blocking the light. I would like to add a little transparency so the light can be cast on the wall.

How can this be done?

Cheers,
Jim

It sounds like this is the parameter I need to turn on, and would do what I want, however, turning this on doesn’t seem to make any difference.