I suppose most of us are pretty familiar with this – impossible triangle optical illusion.

Impossible Triangle Sketch

What about a 3D printed one?

3D Printed Impossible Triangle

It’s actually curved.

Check out the side view.

Don’t mind the triangle, we were too excited to check out the optical illusion instead of cleaning it properly (it was printed in rubber-like material from Polyjet). Do you have any optical illusion stuff to share with us?