Search found 433 matches

by robertw
Tue Oct 30, 2018 1:12 am
Forum: Flippant Forum
Topic: Cut-out paper version of Flippant at MathsJam
Replies: 1
Views: 85

Re: Cut-out paper version of Flippant at MathsJam

...and someone from Singapore MathsJam who created a spreadsheet with one possible solution:
https://twitter.com/nemoyatpeace/status ... 7559536640
by robertw
Mon Oct 29, 2018 3:12 am
Forum: Flippant Forum
Topic: Cut-out paper version of Flippant at MathsJam
Replies: 1
Views: 85

Cut-out paper version of Flippant at MathsJam

MathsJam is a monthly event that takes place at pubs around the world on the same night, and one of the groups comes up with a puzzle sheet for all groups to look at. Last month was our turn, so I suggested a cut-out paper version of Flippant for people to try solving. It was good to see some discus...
by robertw
Tue Oct 16, 2018 2:25 am
Forum: Stella Forum
Topic: Disphenoid tetrahedra
Replies: 2
Views: 113

Re: Disphenoid tetrahedra

How would one define a disphenoid in general? You can find most of Bruckner's noble polyhedra in Stella in "Stella Library->Bruckner". Many of these are actually compounds, and quite a few are compounds of disphenoids. So you could isolate one of those from the compound. And generally, you could use...
by robertw
Sun Oct 07, 2018 12:31 pm
Forum: Stella Forum
Topic: What is this particular model
Replies: 2
Views: 1192

Re: What is this particular model

Here's the rhombicosahedron: https://i.postimg.cc/PCxhq0yM/image.png Take the convex hull with "Poly->Create Convex Hull" and you'll see the hull is a non-uniform truncated icosahedron: https://i.postimg.cc/FdZNzvMD/image.png So try starting with a uniform truncated icosahedron and go the other way....
by robertw
Sun Oct 07, 2018 12:24 pm
Forum: Stella Forum
Topic: Announcing MoStella! Mobile app full of polyhedra.
Replies: 3
Views: 12483

Re: Announcing MoStella! Mobile app full of polyhedra.

Hey Guy, Thanks for the feedback. Unfortunately MoStella was written with development tools I don't use any more and couldn't get to work again last time I tried. Google's native development platform is terrible. If I make a new version of MoStella it will be rewritten with a different dev platform ...
by robertw
Fri Oct 05, 2018 3:35 am
Forum: Stella Forum
Topic: custom image request
Replies: 3
Views: 131

Re: custom image request

Maybe someone here will offer to help. There would be two approaches. First you could get any polyhedron and use your logo as an image on each face. Second would be to try to use your logo as the geometry itself, but this may not be so easy as your geometry may not tessellate together nicely.
by robertw
Thu Oct 04, 2018 2:57 am
Forum: Stella Forum
Topic: custom image request
Replies: 3
Views: 131

Re: custom image request

Can you be more specific? And maybe tell us a bit about your project.
by robertw
Sun Sep 30, 2018 9:35 am
Forum: Polyhedra
Topic: Constructing models with transparent faces?
Replies: 3
Views: 176

Re: Constructing models with transparent faces?

I think it was your post about straws that reminded me about transparent faces and prompted me to ask about it here. Looks like that should say UHU Por (not UHO). Apparently it's intended for gluing styrofoam to other materials. Let me know if you try plastic to plastic, or plastic to paper. One thi...
by robertw
Sun Sep 30, 2018 4:56 am
Forum: Stella Forum
Topic: origin and xyz axes
Replies: 4
Views: 177

Re: origin and xyz axes

I get the feeling you're not seeing what I'm seeing. You say the slightest mouse movement and the model goes off the rails? It should rotate at a sensible pace, roughly keeping the closest point of the model under the mouse. If it's rotating much faster than that for you, then something's different....
by robertw
Sat Sep 29, 2018 5:11 am
Forum: Polyhedra
Topic: Constructing models with transparent faces?
Replies: 3
Views: 176

Constructing models with transparent faces?

Has anyone built physical models with transparent faces? (Either some or all faces)

I'm thinking more of thin materials, like clear plastic, rather than solid glass/perspex tiles.

I tried once, but it just fell apart. Plastic doesn't glue well.
by robertw
Sat Sep 29, 2018 5:08 am
Forum: Stella Forum
Topic: origin and xyz axes
Replies: 4
Views: 177

Re: origin and xyz axes

I think I've answered most of this on your other posts, eg viewtopic.php?p=1723#p1723

There are options both for exporting and for viewing in Stella to orient a model in various ways.
by robertw
Sat Sep 29, 2018 5:02 am
Forum: Stella Forum
Topic: one step forward two steps back
Replies: 1
Views: 96

Re: one step forward two steps back

I replied to your other post re orientation when exporting. For orientation within Stella, just use the View->Orientation menu: https://i.postimg.cc/50tpyRkM/image.png "Default Orientation" will get you back, or you can explicitly look down any relevant symmetry axis, or look at/sit on specific face...
by robertw
Sat Sep 29, 2018 4:56 am
Forum: Stella Forum
Topic: All systems go
Replies: 1
Views: 98

Re: All systems go

When you export a 3D model in Stella a form appears where you can specify an orientation: https://i.postimg.cc/ydWXsSk1/image.png Choose "Sit on" and from the drop-down choose "3-fold axis". You could also choose "Sit on current face/edge/vertex/symmetry" if you first select the item you want it to ...
by robertw
Wed Sep 26, 2018 1:38 pm
Forum: Stella Forum
Topic: creating mitre angles for faces
Replies: 4
Views: 186

Re: creating mitre angles for faces

Yes, as follows: Set the scale of the model from the Scale menu (eg size of inner model) Put this model in a memory slot (Edit->Put Model in Memory, or type m1 to put it in slot 1) Set scale of model to another size (eg size of outer model) Add to model in memory slot (Edit->Add/Blend from Memory->M...
by robertw
Wed Sep 26, 2018 12:49 pm
Forum: Polyhedra
Topic: Nadia's Icosahedron
Replies: 13
Views: 359

Re: Nadia's Icosahedron

Well done Ulrich. I didn't even follow what you did really but that's OK :) To get the hexagons regular, the usual "Poly->Try to Make Faces Regular" doesn't work because they can't all be regular. Instead, use "Poly->Create Spring Model". Tick the "Start with original vertices" box and add "~5" at t...