Chilean artist Fredo (Wladimir Inostroza) draws 3D images on paper. He started one day drawing a butterfly that seemed to be floating above the drawing paper. He added some shade and took a picture. Since then, he has experimented and drawn countless 3D images.
This is a bit similar to the “Out of Bounds” photography technique where you select an object in your photo, cut the surroundings away and draw a frame around it to make it look like it pops out of the frame. Of course, you can let your imagination soar and the sky is then the limit.