Hello from Eric

The place to talk about Stella4D, Great Stella, and Small Stella. Feel free to ask questions about them here.
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EricRegener
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Joined: Sun Aug 03, 2014 10:25 pm

Hello from Eric

Post by EricRegener » Mon Aug 04, 2014 5:22 pm

Dear Robert Webb and other forum members,

I am delighted to discover Stella, your software, your models and your forum. I have been interested in polyhedra since I was in 4th grade and constructed the Platonic (and some Archimedean?) solids from diagrams I saw in school. My late father, a physics professor, saw the models I had made, and in 1954 he happened to see the famous paper on Uniform Polyhedra by Coxeter et al. as it crossed his desk. He bought a copy of the paper and had it bound, and it was my Bible for the next many years.

I constructed a number of Coxeter's models from scratch using drawing instruments. The most complex was the great truncated cuboctahedron, I think - I was fascinated by the little holes! Finally I got interested in coloring the faces and made a compound of five tetrahedra for my future ex-wife, with colors that were different shades of each other for each of the five tetrahedra. (If I can find a picture of the thing I will post it.)

Now that I have finally retired I would like to take up this hobby again. Stella makes so many things possible that I could only imagine before. Thank you for your wonderful contribution to the world of knowledge and possibility!

There are many things I would like to do here which I'm not sure I yet know how to. For example, I would like to make complex models whose "unfolded" nets include more than one color, to avoid having to glue together so many eensy weensy tiny tabs. When I can describe better what I want, I'll make specific posts on the "Making Polyhedra" subforum.

Thanks again for this wonderful software and all the ideas it suggests!

All the best, Eric Regener

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Peter Kane
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Post by Peter Kane » Tue Aug 05, 2014 2:41 pm

Welcome to the stella fan-club ! I'm sure stella will give you hours of fun and I look forward to seeing some of your models. It was interesting to read how you got into the subject. I myself saw some models at a museum around 1970 and it was love at first sight. I can still picture some of the models, but I can't for the life of me remember which museum I saw them in (I suspect that it was the science museum in London, but it could have been Munich).

Pete K

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robertw
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Post by robertw » Sun Aug 10, 2014 6:41 am

Hi Eric, and welcome to the forum!

Thanks for your feedback. I know what you mean about the great truncated cuboctahedron. Those small triangular holes that open into large caves inside. It's amazing how a bunch of regular polygons satisfying the seemingly simple rules of uniformity can lead to such diverse three dimensional shapes.

I remember polyhedra being hard to come by too. Orthogonal sketches in old books left a lot to the imagination. Now computers allow us to see them as solids rotating in 3D, and with Stella, to print out nets for their physical construction in the real world (or even to be 3D printed directly). And of course, it's also easier to investigate new stellations, facetings, and other polyhedra like never before.

You asked about printing nets which include more than one colour. The menu item you need is "Nets->Net/Paper Color Mixing". This is actually a submenu, which you can read about in the manual:

http://www.software3d.com/StellaManual. ... olorMixing

Thanks,
Rob.

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oxenholme
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Post by oxenholme » Sat Aug 16, 2014 11:48 am

Hi Eric!

My first bible was Mathematical Models by Dr H. Martyn Cundy & A.P. Rollett. My second was Uniform Polyhedra by H.S.M. Coxeter, Dr J.C.P. Miller & M.S. Longuet-Higgins.

Way back then I used to sit and look bewildered at the drawings of the non-convex snub polyhedra.

History is repeating itself. A month or two ago I stumbled on the net that I drew for one of the snubs from Mr Buckley's numerical data. I didn't try to make it back then, but this time I completed it using 17 colours.

I've been sat psyching myself up to make the snub with the tiny facets, again I'll be using Mr Buckley's numerical data, but this one will use 22 colours - 6 for the pentagrams, 10 for the icosahedral triangles and another 6 for the snub triangles.

If you listen you'll know when I've begun as the air turns blue.

Image

EricRegener
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Post by EricRegener » Sun Aug 17, 2014 3:31 pm

Peter Kane, RobertW, Oxenholme,

Thanks for your kind welcomes and your replies! Sorry I am so slow to write. It's interesting to read from each of you about the history of your fascination with polyhedra and how you got into them.

RobertW, thank you for pointing out "Paper color mixing," which I had not noticed at all. This option is really great, and the nets you show are wonderful - just for one example, the great icosicosidodecahedron. Did you work out the nets yourself? I'm so impressed.

Now I can print these unfolded nets to PDF and pull them into CorelDraw to fix up the colors... somehow. Thirty-two nets, even if they are complex, are so much easier to deal with than 1232 individual facelets! :roll:

Oxenholme, thank you for the photo of the almost-completed, umm, snub icosidodecadodecahedron. (I wish the names weren't all twelve syllables long!) It's fascinating to see inside it!

I haven't actually done any real work yet, as you might have gathered by now. I've been assembling materials. I found a blueprint company with a flatbed printer that will print in color on heavy-weight A3 paper.

Soon I'll be going (back) to China, maybe they have equipment like that there too. I want to leave Montreal before the snow sets in.

I am very happy to join your community, thanks again for your welcome & your enthusiasm.

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robertw
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Post by robertw » Thu Aug 21, 2014 11:55 am

EricRegener wrote:RobertW, thank you for pointing out "Paper color mixing," which I had not noticed at all. This option is really great, and the nets you show are wonderful - just for one example, the great icosicosidodecahedron. Did you work out the nets yourself? I'm so impressed.
Stella works out all the nets. I just had to work out how to make it do that!

For most models, I prefer to let Stella separate the colours and print onto coloured paper. There's more edges to glue, but nets with lots of parts become unweildy and may bend or tear under their own weight.
I found a blueprint company with a flatbed printer that will print in color on heavy-weight A3 paper.
I find not-too-heavy paper is better, but you might be making larger models than me.

EricRegener
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Post by EricRegener » Sun Aug 31, 2014 4:12 am

Rob,

I was blown away - again - by what Stella can do. I assigned colors to all the faces of a polyhedron and found, to my delight, that Stella automatically prints the unfolded nets with all the colors I chose, in all the right places. I feel like I've gone to heaven!

Sorry to go all starry-eyed over this, but you have to imagine what it was like to design these things and assemble then by hand - almost 60 years ago, before computers even were!

I'm finally working on a model, will send pictures when it's ready. Should be done before I leave Montreal for China in a few weeks.

Eric

EricRegener
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Finally constructed sth!

Post by EricRegener » Tue Sep 16, 2014 9:03 pm

I finally constructed something! Not very pretty, but so much fun! One image below, others in the Polyhedron Models subforum. I'm delighted with the color mixing and color choice options, and with the fact that the nets are automatically printed with the colors you chose in the display.

Rob, thanks again for putting together this wonderful software and making it available for all of us!

Eric

Image

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