I’ve been looking lately into the idea of creating 3D images using a technique called crossview. Basically, it’s two pictures side by side, but when you look at it and slowly cross your eyes, they merge into a “third” image, that appears 3D. The brain creates this in real time by noting the differences between the two images and interprets that as true stereoscopic vision. The brain is amazing.

Here is how to view them:
how to view crossview 3D

And here are some samples I made!

Note that even reflections take on 3D!