A Krasnikov Tube is a permanent space warp created behind a spaceship as it travels at near lightspeed to some distant star system, and then uses the resulting tube for the return trip. The tube would provide a distortion of space such that it gets you back home shortly after you left. Painted in Photoshop, the main image uses no 3d, just various photos and hand painted elements. Will post a tutorial on the process in the near future.
Part of the Megastructures book project, to be released late 2021 / early 2022: http://www.neilblevins.com/books/megastructures/megastructures.htm