How to make City Building Billboards with emissive Lights?

Hi, anyone know how to make the Billboards used in this demo? - - YouTube

I am making an Archviz scene and need to create an apartment in a city, with a city backdrop.

What’s the confusion? You can take an image of buildings and adjust it in Photoshop to get the illuminated windows more isolated and just use that in the emissive slot in a material in UE4

Great, thanks for the feedback.