Casting light without surface to cast light on

Hello. What is the best way of display light without any surface to cast light on? I want to display light cone but I don’t want any wall behind my light emitor.

This is more understandable in pictures:

First picture: There is no wall between cube and horizontal pipe visible behind the cube. Light is on, but has no sufrace to be cast on.

Second picture: There is wall between cube and pipe. Light cone is visible because is casted on wall.

Third picture: This is what I want. There is no wall between pipe and cube, still light cone is visible.

I don’t have a surface behind cube but i want light visible. I would like to cast shadow by moving the cube.
If I use static mesh I will need to place surface behind the cube.
I tried use particle system like light emitter but this seems to be very ineffective.

What is best way to achieve this effect?

What you ultimately want is volumetric lights, which aren’t available in UE4 yet–it’s one of the next-gen type features.

Thanks for you reply.
What would you recommend to use instead of volumetric lights ?

Can you make like a partially transparent static mesh in that conical shape you’re going for? I think that’s how it was done in the ye olde days.