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Talk:Great icosahedron

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For the Kepler-Poinsot solids, I think it would be better to forego the symmetric colouring, and instead use an arrangement of multiple colours so that neighbouring faces do not share the same colour. This should let the faces stand out more while keeping consistent lighting. Unfortunately my copy of
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On further examination of the SVG, I see that different parts of the same triangular face have different shades of red that cannot be explained by their orientation (because the parts oriented towards the viewer are darker instead of brighter). This is pretty much the same problem as the inconsistent
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I'm not sure what's meant about it being "nigh-impenetrable". The SVG looks pretty intelligible to me. Furthermore, I can't see that "indecisive on when shadows should exist for the edges" is sufficient grounds for rejecting that image. Surely, what's most important is that it's not misleading.
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misleading: as a result of several face orientations having the same shade of red, together with the absence of edge lines where faces intersect, some of the hollows appear as flat faces, and therefore it shows a number of the faces as being pentagrams. In fact, all the faces are triangles.
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should be able to do this (IIRC Stella has such schemes listed as icosahedral colour arrangements or something similar). In the meantime, however, the lighting concerns lead me to favour the current PNG until such a replacement is made (preferably for the other three regular stars as well).
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Thanks! I think both versions (multicoloured PNG and original PNG) are good now. I prefer the multicoloured one as the lede image, but not strongly since sometimes the pure red one reflecting its symmetries makes more sense (as in the truncation sequence further down the article).
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I'll ask around where the name came from. Norman Johnson named all the full symmetry constructions. Richard Klitzing has the only list I know for all of the Wythoff constructions and includes 3 names: great icosahedron, retrosnub tetrahedron, retrosnub tetratetrahedron.
401:; a discussion will now take place over on Commons about whether to remove the file. This gives you an opportunity to contest the deletion, although please review Commons guidelines before doing so. 325:; a discussion will now take place over on Commons about whether to remove the file. This gives you an opportunity to contest the deletion, although please review Commons guidelines before doing so. 249:; a discussion will now take place over on Commons about whether to remove the file. This gives you an opportunity to contest the deletion, although please review Commons guidelines before doing so. 140: 612:'s comment on reverting to the PNG: "that SVG which is nigh-impenetrable at small sizes and seems oddly indecisive on when shadows should exist for the edges - nah, not better" 790:
Thanks both. It's certainly better now. Not perfect, but better. It really ought to be an SVG, but anyhow. Can't make up my mind what I think to the coloured version.... —
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This isn't to say the SVG can't be improved. But since the PNG is misleading, I can't see it as being better on any level. As such, I say the right course of action is:
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shadows on some edges. So I would claim that the SVG is actually more misleading as it doesn't reflect how the great icosahedron looks from any angle, while the PNG does.
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I added a multicolored face version above, similar orientation. I also remade the original one to better show face-plane shading.
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I'm glad to help. I agree SVG can be superior, but I did upload as a large 2000x2000 pixel image (slightly smaller cropped).
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for its octahedral/pyritohedral construction in 2002 and 2006 messages. But I still can't say about published references.
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Produce an SVG that shows, accurately and more clearly at small sizes, what a great icosahedron looks like
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If this can't be done quickly, then use the existing SVG for the time being, as the lesser of two evils.
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on Knowledge. If you would like to participate, please visit the project page, where you can join
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Stella (the software that made the original PNG) died with my previous computer, but
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Coxeter lists the | 2 3/2 3/2 construction in his paper, but doesn't name it, IIRC.
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This name is not supported by the references given. I strongly suspect that it is
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and needs to be deleted. Can anybody confirm a source for this name? — Cheers,
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Why is it that the net of the great icosahedron is not given? Presumably there
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then you may need to upload it to Knowledge (Commons does not allow fair use)
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then you may need to upload it to Knowledge (Commons does not allow fair use)
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then you may need to upload it to Knowledge (Commons does not allow fair use)
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41 {2 3/2 3/2} s*TT = Retrosnub tetratetrahedron = great icosahedron
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File:Second compound stellation of icosahedron.png Nominated for Deletion
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File:Third compound stellation of icosahedron.png Nominated for Deletion
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41 {3/2}|4 2| s*O = Retrosnub octahedron = great icosahedron
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Talk:Great_dodecahedron#Conway-style_notation_for_star_polyhedra
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File:First stellation of icosahedron.png Nominated for Deletion
15: 193:. See the mathworld article on the great icosahedron. 101:, a collaborative effort to improve the coverage of 412:If the image isn't freely licensed and there is no 336:If the image isn't freely licensed and there is no 260:If the image isn't freely licensed and there is no 306:File:Second compound stellation of icosahedron.png 230:File:Third compound stellation of icosahedron.png 181:To make the great icosahedron you start with a 625:. At the size they're shown in this article: 8: 615:This is applicable to both this article and 189:dimples. In the dimples one needs to affix 19: 47: 502:, sr{3/2,5/3}, compared to sr{3/2,3/2}. 442:Conway-style notation for star polyhedra 382:File:First stellation of icosahedron.png 627: 582: 49: 421:This notification is provided by a Bot 345:This notification is provided by a Bot 269:This notification is provided by a Bot 384:, has been nominated for deletion at 308:, has been nominated for deletion at 232:, has been nominated for deletion at 7: 95:This article is within the scope of 416:then it cannot be uploaded or used. 340:then it cannot be uploaded or used. 264:then it cannot be uploaded or used. 38:It is of interest to the following 14: 835:Low-priority mathematics articles 500:great retrosnub icosidodecahedron 115:Knowledge:WikiProject Mathematics 830:Start-Class mathematics articles 654: 642: 630: 597: 585: 390:Deletion requests September 2011 373: 314:Deletion requests September 2011 297: 238:Deletion requests September 2011 221: 118:Template:WikiProject Mathematics 82: 72: 51: 20: 380:An image used in this article, 304:An image used in this article, 228:An image used in this article, 135:This article has been rated as 543:12:26, 18 September 2014 (UTC) 517:I found message archives from 512:10:58, 18 September 2014 (UTC) 489:09:24, 18 September 2014 (UTC) 1: 649:Great icosahedron colored.png 465:18:04, 23 December 2013 (UTC) 433:11:01, 3 September 2011 (UTC) 357:10:58, 3 September 2011 (UTC) 281:10:55, 3 September 2011 (UTC) 109:and see a list of open tasks. 576:The two images of this shape 388:in the following category: 312:in the following category: 236:in the following category: 208:14:21, 28 August 2009 (UTC) 851: 568:23:50, 18 March 2015 (UTC) 525:as far back as 1996, and 176:10:09, 26 July 2009 (UTC) 134: 67: 46: 800:14:31, 31 May 2018 (UTC) 764:14:11, 30 May 2018 (UTC) 742:10:33, 30 May 2018 (UTC) 728:02:23, 30 May 2018 (UTC) 696:21:39, 29 May 2018 (UTC) 141:project's priority scale 98:WikiProject Mathematics 425:CommonsNotificationBot 349:CommonsNotificationBot 273:CommonsNotificationBot 28:This article is rated 661:Great icosahedron.svg 637:Great icosahedron.png 604:Great icosahedron.svg 592:Great icosahedron.png 523:retrosnub tetrahedron 471:Retrosnub tetrahedron 191:pentagrammic pyramids 580:Currently, we have: 531:retrosnub octahedron 121:mathematics articles 498:. 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