What's the name of that 3d thing where you cross your eyes

I can’t think of the name (in fact, I’m not sure if it has a name).

You know those 3d things where if you have a tiled background, and then you sortof cross your eyes, and you see the 3d in it? Ususally, there are books with 25 or so pages of those in them, and after you are done, your eyes sometimes feel funny from staring so strangely for too long. :smiley:

I have a sortof idea in my mind how it works, and I tried creating something like that in ActionScript using a DisplacementMapFilter, and it didn’t turn out as simple and elegant as I thought it would. :trout: In fact, it was a catastrophic failure.

So if I can get the name of that 3d thing, I can likely find out how it works exactly, and see if I can get a prototype working.