If Ruz's trick doesn't work, then go down to element mode and do "unhide all" but based on the video I don't think that will work in your particular case.
Maybe taking a look at Doctor Grordbort's art might be useful here. It's distinctly 50s pulp sci-fi, but it has some of the decorative elements of art deco.
Probably easier to split the edges around the collar/cuffs, then element select the inside and delete. (Or loop select the polys at the collar/cuffs and delete those, then delete the inside).
the gunship was one of the main elements that I wanted to use it to add more dynamic to the scene ... I was inspired by some concepts of this movie and finally, I designed this one...
There's also countless filters on Filter Forge that can be made seamless, and tweaked and altered, or even torn apart to see how they work, that create nebulae for 2D elements.
Can you give us any insight in the complex UE4 materials with the moving elements and flow maps or how you create the abstract shapes in your environments?