Look at the two pictures with your eyes crossed until you can see 3 pictures instead of two. When you can see three pictures, concentrate on the center picture and you will see it in 3D.
Just did your 3D exercise, wow who'da thunk! At first I crossed my eyes too much and it didn't work. As I relaxed my eyes it popped in. Sort of like those pictures of a few years ago that you'd stare at and a mush of dots would become an image. Is it the different hues, the slightly different angle or both. Quite interesting. Been watching your projects through the years. You're a fountian of ingenuity. All the best, Richard
