Henry Segerman's recent shapeways model of the {3,3,6} H3 honeycomb inspired me to make a similar model using...

Henry Segerman's recent shapeways model of the {3,3,6} H3 honeycomb inspired me to make a similar model using different media... laser engraved crystal.  I took the tessellation a few levels deeper and rendered edges with proper thicknesses in the Poincare ball model.

The print has a very ghostly feel to it, which is quite nice for including lots of tetrahedra and still being able to see the the cells living towards the interior of the ball.  I think it would work well with even more cells added.  Lighting has a big effect on how things look!

The {3,3,6} is one of 15 regular honeycombs in hyperbolic 3-space.  It is one of 11 that have infinite cells and/or vertex figures.  For more info, see:

Henry's video about his shapeways model:
Regular triangulation of H³

Coxeter's paper, "Regular Honeycombs in Hyperbolic Space":
http://www.mathunion.org/ICM/ICM1954.3/Main/icm1954.3.0155.0169.ocr.pdf









Comments

  1. Wow, that looks amazing! Can I buy one?

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  2. Yes, but as luck would have it, you don't need to :)  They accidentally sent me two of these, so I have an extra with your name on it.  Shoot me an email with a mailing address, and I'll drop it in the mail this week.  (I don't have an extra lighted base, however - those are available at http://www.lasercrystalawards.com/catalog/presentation-bases.html)

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  3. For anyone else interested, these can be purchased from www.lasercrystalawards.com for a little under $40.  You can upload a dummy model file during checkout and leave a note pointing them to the (large) stl file here:  http://www.gravitation3d.com/lasercrystal/H3_336.stl

    Trying to upload this large file to their servers fails, which is the reason for the dummy model file.

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  4. Roice Nelson Thanks so much! I'll email you my address. Someone needs to do a Shapeways for crystal engraving...

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  5. Very nice! How the STL file is rendered? As the vertices of triangles or do they generate some new dots?

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  6. Fantastic. If it's not too much trouble, I'd love to see a video where the camera moves around the cube!

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  7. Vladimir Bulatov, the rendering is the result of many tiny dot microfractures in the glass.  The stl I made is just triangles though (about 1.3 million of them).  Laser crystal awards does the rest.  I know Bathsheba has made her own special algorithms for her engraved crystals controlling exactly where dots go, but I haven't found this necessary.

    http://www.bathsheba.com/crystal/process/

    I will say that on the {3,3,6} model, only the surface gets turned into dots, and this does have a little bit of a downside near the really crowded vertices (leading to small voids), so that is potentially improvable if I tried to control the dots myself.

    By the way, this is the third model I've had engraved, and all have been very pleasing.  Here's some pics of another:

    https://lh3.googleusercontent.com/hdkOy3am_6Ao8sOgilX1Fl98c_QIuK42FEs999VRVg4ANPZ5Zb18YRd995T3Erd8rSnsVPHrRSOjv4fg_nobvGwDgLUwiHn_v00=s0

    The last was a portion of a 120-cell, but it was a gift and unfortunately I didn't take pics before giving it.

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  8. Allen Knutson, I just made a video for you.  All I have to record is my phone, and things are a little blurry, but hopefully it gives a view like you were hoping :)

    {3,3,6} H3 Honeycomb

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  9. Vladimir Bulatov, sorry, I misunderstood your question earlier, so edited my previous response.  In short, they generate new dots (it is not just triangle vertices that are rendered).

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  10. This may be of interest to you Mark Bruce, perhaps you could have your bust in optical crystal by this means.

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  11. DON,T UNDERSTAND A WORD BUT LOVE THE PICTURE OF YOU AND SARAH  SEND ME ONE AND THE CHRYSTAL IS BEAUTIFUL  LOVE GRANDMA

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  12. Looks cool. Maybe I will try to 3d print this stereolithography file on the rapid prototype machine at work. :)

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  13. Roice Nelson I'm told that the package has arrived in Oklahoma, I'm looking forward to seeing it in person!

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