Search found 479 matches

by robertw
Sun Jun 09, 2019 2:26 am
Forum: Stella Forum
Topic: 4D Compounds from verf
Replies: 9
Views: 318

Re: 4D Compounds from verf

Ah, been a while since I did this so I'd forgotten some of how it worked, but turns out I did already add a way to set the dual name in the vertex figure. Just add "cell-of-" at the start of the dual name. The dual of the vertex figure is a cell of the dual. This tells Stella to extract the name of ...
by robertw
Thu Jun 06, 2019 1:49 pm
Forum: Stella Forum
Topic: 4D Compounds from verf
Replies: 9
Views: 318

Re: 4D Compounds from verf

I think that's correct, to count compound vertices twice, and corealmic cells twice. They are two separate items that happen to be in the same place/plane. Same happens in 3D, coplanar faces are still two faces. Re 4D dual naming, you mean you'd like to be able to name the dual even when only saving...
by robertw
Sun May 19, 2019 5:04 am
Forum: Stella Forum
Topic: 4D Compounds from verf
Replies: 9
Views: 318

Re: 4D Compounds from verf

Hmm, I don't remember, but could just come down to what order the faces are defined in, which causes it to grow each vertex in a different order.
by robertw
Wed May 15, 2019 1:24 am
Forum: Stella Forum
Topic: 4D Compounds from verf
Replies: 9
Views: 318

Re: 4D Compounds from verf

I was happy to get vertex figures to work for all 1849 uniform polychora and a bunch of scaliforms, and even some compounds. But yes, compounds are tricky because there's often multiple ways to match at each vertex, and if you take the wrong branch it can continue infinitely far without ever connect...
by robertw
Thu Apr 25, 2019 2:21 am
Forum: Polyhedron Models
Topic: PolyCross
Replies: 4
Views: 13120

Re: PolyCross

Interesting idea. Do the words always go clockwise around each number?
by robertw
Thu Apr 25, 2019 2:17 am
Forum: Polyhedron Models
Topic: Genus-41 Stewart toroid
Replies: 4
Views: 340

Re: Genus-41 Stewart toroid

Thanks Ulrich. No, if they were both regular it would be a new Johnson solid! The decagons are regular, but the dodecagons are not.
by robertw
Sat Apr 13, 2019 2:16 pm
Forum: Polyhedron Models
Topic: Genus-41 Stewart toroid
Replies: 4
Views: 340

Re: Genus-41 Stewart toroid

It's a fun investigation of something similar to Johnson solids but with one or two restrictions removed. Been a long time since I read it though.
by robertw
Tue Apr 09, 2019 2:13 pm
Forum: Polyhedron Models
Topic: Genus-41 Stewart toroid
Replies: 4
Views: 340

Genus-41 Stewart toroid

I just finished a paper model of a new Stewart toroid I discovered a while ago. This has all regular faces and is non-self-intersecting, with genus 41. All edges of the convex hull are also edges of the model (another one of Stewart's criteria). See my page about it at https://www.software3d.com/Web...
by robertw
Wed Feb 27, 2019 12:56 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 1619

Re: Non-Uniform 4D

No sorry, you can't do that. The built-in ones that ask are not from files at all, they are built directly into the code and can handle asking for a parameter.
by robertw
Sun Feb 17, 2019 8:50 am
Forum: Stella Feature Requests
Topic: Curved Shapes
Replies: 1
Views: 411

Re: Curved Shapes

Stella probably won't ever really handle curved surfaces well, although maybe it could have a way to smooth a polyhedron by creating more geometry. Another one for the todo list.
by robertw
Mon Feb 11, 2019 12:24 pm
Forum: Polyhedra
Topic: Solved twisty puzzle
Replies: 5
Views: 693

Re: Solved twisty puzzle

And I've never even listened to King Crimson :)
by robertw
Sun Feb 10, 2019 2:14 pm
Forum: Polyhedra
Topic: Solved twisty puzzle
Replies: 5
Views: 693

Re: Solved twisty puzzle

The standard Rubik's cube and many of its variations aren't too hard once you know a few basic principles. I gave a 7x7x7 cube, a teraminx and various other twisty puzzles which aren't too hard, although they may take a long time due to the number of pieces. This one though, the "curvy starminx", wa...
by robertw
Sun Feb 10, 2019 2:08 pm
Forum: Polyhedron Models
Topic: Marshmallow model
Replies: 2
Views: 375

Re: Marshmallow model

We certainly ate a few marshmallows along the way. And the model didn't survive the night.
by robertw
Sun Feb 10, 2019 3:49 am
Forum: Polyhedra
Topic: Solved twisty puzzle
Replies: 5
Views: 693

Solved twisty puzzle

After sitting scrambled on my shelf for years, I finally figured out how to solve this beautiful puzzle! Seen here sitting on the page of scribbles made while solving.

https://www.facebook.com/photo.php?fbid ... 1739136522


Image
by robertw
Sun Feb 10, 2019 3:44 am
Forum: Polyhedron Models
Topic: Marshmallow model
Replies: 2
Views: 375

Marshmallow model

Here's a model I made with marshmallows and toothpicks at MathsJam Melbourne. It could be any of the four polyhedra shown, as they all have the same edges. Three are uniform, the 4th is the compound of 5 cubes. Interesting that you can form regular triangles, squares, pentagons, and pentagrams from ...