basics on how Anaglyph ( red/blue) 3d works..
the red lens sees blue dot as black and red dot disappears
the blue lens sees the red dot as black and the blue dot disappears
the mind assumes that the black dot coming from each eye is the same dot
and plots it's position..

1 the dot appears to float above the paper
2 they overlap and appear on the surface
3 shift the other way dots appear below the surface

the concept is easy and applying it can be as complicated as you want to make it by having different parts deep or protruding. it can be a good puzzle.

this shows the difference between the red and blue by moving between the 2 views in black and white.

zoomed