=======================================
Sugihara Kokichi's "impossible objects"
=======================================
:CreationDate: 2019-10-05 12:22:35
:Id: modelli/sugihara-impossible-objects
:tags: - japanese
       - 3dPrint

In September 2019, `Japan House`_ hosted a presentation by `SUGIHARA
Kokichi`_, inventor of many optical illusions realised as solid
objects. He had brought some examples, and I took pictures (below).

Recently, I have managed to `re-create some of his models
</cgit/impossible-objects/tree/ambiguous-cylinders.scad>`_.

An arrow that always points to the right:

.. video:: arrow.mp4
   :loop: true
   :type: video/mp4
   :width: 320
   :height: 240

This is what it looks like when viewed from above:

.. image:: arrow-from-above-t.jpg
   :target: arrow-from-above.jpg

Four blue circles, and four heart shapes, but when seen from the other
side (here, through a plain mirror) it's a blue 4-pointed star and the
four suits of playing cards:

.. image:: card-suits-plus-pointy-circles-t.jpg
   :target: card-suits-plus-pointy-circles.jpg
   :class: twitter

and this is what they look like from the side:

.. image:: card-suits-plus-pointy-circles-from-side-t.jpg
   :target: card-suits-plus-pointy-circles-from-side.jpg

Six squares, or six circles?

.. image:: square-circles-t.jpg
   :target: square-circles.jpg

from the side:

.. image:: square-circles-from-side-t.jpg
   :target: square-circles-from-side.jpg

A ring of circles, and three concentric circles, but from the other
side it's a ring of squares, and three intersecting circles:

.. image:: braid-and-nested-t.jpg
   :target: braid-and-nested.jpg

seen from the side:

.. image:: braid-and-nested-from-side-t.jpg
   :target: braid-and-nested-from-side.jpg

detail of the concentric / intersecting circles from above:

.. image:: nested-from-above-t.jpg
   :target: nested-from-above.jpg

The four suits of playing cards, but the bottom half is made by the
reflection of the top half:

.. image:: card-suits-plane-t.jpg
   :target: card-suits-plane.jpg

Above the mirror, a fish; inside the mirror, its bones:

.. image:: fish-bone-t.jpg
   :target: fish-bone.jpg

A flower above the mirror, its flowerpot inside:

.. image:: flower-pot-t.jpg
   :target: flower-pot.jpg

There was also a workshop, in which we built this thing:

.. image:: slides-good-angle-t.jpg
   :target: slides-good-angle.jpg

If you put marbles on the slides, they roll toward the centre,
appearing to roll upwards:

.. video:: slides-up.mp4
   :type: video/mp4
   :width: 500
   :height: 300

This is how the same object looks from the opposite side:

.. image:: slides-bad-angle-t.jpg
   :target: slides-bad-angle.jpg

and another side-view:

.. image:: slides-from-side-t.jpg
   :target: slides-from-side.jpg

Marbles, of course, roll downwards:

.. video:: slides-down.mp4
   :type: video/mp4
   :width: 500
   :height: 300

.. _`Japan House`: https://www.japanhouselondon.uk/
.. _`SUGIHARA Kokichi`:
   http://www.isc.meiji.ac.jp/~kokichis/Welcomee.html