The general rule for Christopher Nolan's work is that if an effect looks unearthly and impossible, he probably demanded a way to do it for real. For example, remember in Interstellar when (spoilers ahead, dummy) Matthew McConaughey flies into a wormhole and sees the intangible fabric that weaves together space and time? You know, this trippy s**t:
Pictured: God's butthole.
You probably didn't even think about how they made that scene, because, well, this is exactly what CGI was invented for. How else could they do it, by swinging McConaughey in front of some sort of fucked up fun house? Yeah, pretty much.