Search found 76 matches

by marcelteun
Thu Apr 01, 2021 5:31 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

Hi I created my own web-page about Crossohedra. Then I have all the freedom, e.g. use "Crossohedra" instead of Sharpohedron. The page is here: https://tunnissen.eu/polyh/crossohedra/list.html And it is far from complete and needs a lot of work still. To this page I added a few Crossohedra with prism...
by marcelteun
Wed Mar 31, 2021 5:38 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

Updated the list below: Renamed crosso-S4xI_o2o4.off to crosso-S4xI-o2_and_o4.off Added: https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/crosso/crosso-S4xI-o2_and_o4-faceted.off&distance=45&stencil=on https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/crosso/crosso-S4xI-o4_to_o3-f...
by marcelteun
Tue Mar 30, 2021 6:19 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

In some cases where the crosses are on the 2-fold axes it could be a good idea to extend the crosses to obtain regular faces. E.g. https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/crosso/elongated_crosso-S4A4-o2.off&distance=25 https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/cro...
by marcelteun
Mon Mar 29, 2021 7:34 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

Updated the list below Added one by Ulrich: https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/crosso/Faceted_Augmented_Trunc_Cubocta_2.off&distance=40&stencil=on Also did some renaming and added this one https://tunnissen.eu/polyh/local_off.html?off_file=etc/off/crosso/crosso-S4xI-o4_to_o3-...
by marcelteun
Wed Mar 17, 2021 10:32 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

Updated the list below
by marcelteun
Mon Mar 15, 2021 9:07 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

I updated the list below. Almost all names were updated. I will try to keep that list up to date. the links from the other posts might become broken later.
by marcelteun
Mon Mar 15, 2021 9:37 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Crossohedra

Added one with prism symmetry to the list below:
https://tunnissen.eu/polyh/local_off.ht ... istance=20 (by Don Romano)
by marcelteun
Mon Mar 15, 2021 7:49 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Crossohedra

Ulrich wrote:
Mon Mar 15, 2021 7:37 am
Up to now the best one imho was this:
https://tunnissen.eu/polyh/local_off.ht ... istance=15
Yes, that one I like too. I built a model of the first one, but that one is going to be the next one. The snub, I didn't like so much, though.
by marcelteun
Mon Mar 15, 2021 7:31 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Crossoshedra

by marcelteun
Sun Mar 14, 2021 6:54 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Crossohedra

Ulrich wrote:
Sun Mar 14, 2021 4:35 pm
The penultimate is the best.
Which one is that?

I updated the list from before with
https://tunnissen.eu/polyh/local_off.ht ... istance=42 (by Don Romano)
https://tunnissen.eu/polyh/local_off.ht ... istance=35
by marcelteun
Sat Mar 13, 2021 10:46 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Crossohedra

I found some more variations on this theme. So are super simple and some can be found in Brückner, some are quite neat, though they are probably rediscoveries, but that doesn't spoil the fun. The following models were found by Don Romano, Ulrich Mikloweit and me (last updated 2021-03-17) Tetrahedra...
by marcelteun
Thu Mar 11, 2021 9:34 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Sharpohedron

Good found, thanks Ulrich, also from my friend Don! I was quite convinced this would be a rediscovery, since it was such a simple model. Apparently it was known at least in 1568. I think I will build a model of it in the Swiss colours. And I might look into more of these "positive" models. Cheers! M...
by marcelteun
Wed Mar 10, 2021 7:57 pm
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Re: Crossohedra

Yes, that is another way of looking at it! It seems that in his book from 1900 Brückner did come a"cross" some polyhedra with the cross (as pointed out by my friend). See for instance on the right side of plate 8: row 1, #2 and row 3, #2. The former can easily be transformed by moving the crosses to...
by marcelteun
Wed Mar 10, 2021 10:54 am
Forum: Polyhedra
Topic: Sharpohedron
Replies: 18
Views: 736

Sharpohedron

Hi Some time ago George Hart posted a polyhedron on Instagram and some time late, since he got some questions, he made a little video, which can be found here: https://www.youtube.com/watch?v=D1tAv3cfmvI&authuser=0 I forwarded this to a friend of mine, Don Romano, who quickly built a model. Then he ...