Hi!
At Future Lighthouse we wanted to record and display stereo billboards like Kite&Lightning’s “Senza Peso” with the latest versions of Unreal, and I achieved this solution. It’s a shader that checks in what half of the screen is being rendered the pixel and applies the alpha mask from the offsets. You can test it with the videos of senza peso’s project. We have achieved nice results with DK2 and UE 4.9.2.
Enjoy 
