Search found 42 matches

by ndl
Fri Feb 08, 2019 4:05 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

I figured out the problem: I was using the wrong formula to calculate the vertices so the ones I had were creating coplanar faces so that's probably why it was crashing. Once I fixed the formula it worked no problems.
by ndl
Thu Feb 07, 2019 2:57 pm
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

I made the following .off file but when I open it in stella4d and ask it to make convex hull the program crashes. Do you know what could be the problem?

cylindrical crind.off
by ndl
Mon Jan 21, 2019 3:39 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

Yes, convex hull is what I need and it works just fine. Thanks again
by ndl
Sun Jan 20, 2019 3:50 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

It got confused when I listed cells, but I did a listing of just the vertices and it created the 4D convex hull for me! Thanks for your help.
by ndl
Thu Jan 17, 2019 4:17 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

I'm trying to work with .off files to create 4D non-uniforms, but it's way too tedious to try to figure out all the faces and cells that would connect the vertices. I found this program called qhull (www.qhull.org) that will calculate the convex hull and create an .off file from input vertices, but ...
by ndl
Tue Jan 01, 2019 4:24 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Re: Non-Uniform 4D

What about an ability to cut off pieces of uniform polyhedra? That would give rise to lots of interesting non-uniforms. Maybe create it by choosing a cross section to cut it at (this could really be a great feature for 3D also!).
by ndl
Mon Dec 31, 2018 4:45 am
Forum: Stella Forum
Topic: Non-Uniform 4D
Replies: 17
Views: 2659

Non-Uniform 4D

I just got Stella4D and I'm trying to play around with it. It seems you covered pretty extensively 4D uniforms, but I had trouble trying to create non-uniforms. I wanted to make an Icosahedral pyramid, for example, so I tried using a J2 pentagonal pyramid as vertex figure to create it, but it only g...
by ndl
Thu Dec 20, 2018 5:07 am
Forum: Stella Feature Requests
Topic: Augmenting with polyhedra
Replies: 3
Views: 814

Re: Augmenting with polyhedra

That's good to know. Thanks again
by ndl
Thu Dec 20, 2018 4:13 am
Forum: Stella Feature Requests
Topic: Augmenting with polyhedra
Replies: 3
Views: 814

Re: Augmenting with polyhedra

Never mind, it seems that feature is already available and I overlooked it.
by ndl
Thu Dec 20, 2018 3:39 am
Forum: Stella Feature Requests
Topic: Augmenting with polyhedra
Replies: 3
Views: 814

Augmenting with polyhedra

Could there be a way to choose which matching face of existing polyhedron is used for augmentations? Often I find I want to use a different one than which is automatically chosen.
Thanks
by ndl
Thu Dec 20, 2018 2:54 am
Forum: Polyhedra
Topic: New Torus
Replies: 9
Views: 2211

Re: New Torus

And an alternate version with antiprism and cupola replacing rotunda:
J76 Genus 6 alt.JPG
J76 Genus 6 alt.JPG (57.53 KiB) Viewed 1932 times
by ndl
Thu Dec 20, 2018 2:35 am
Forum: Polyhedra
Topic: New Torus
Replies: 9
Views: 2211

Re: New Torus

Even better, I got one with a genus of 6 and retaining the original symmetry of J76 by cutting through with a Dodecahedron and 5 J11s
J76 Genus 6.JPG
J76 Genus 6.JPG (46 KiB) Viewed 1933 times
Still quasi-convex!
by ndl
Wed Dec 19, 2018 7:20 pm
Forum: Polyhedra
Topic: New Torus
Replies: 9
Views: 2211

Re: New Torus

So I created a new toroid that has Stewart's quasi-convex property that doesn't seem to be mentioned in his book (I only have first edition, though):
J76 Torus.JPG
J76 Torus.JPG (44.46 KiB) Viewed 1935 times
This is J76 with a rotunda and two icosahedra removed for a genus of 2.
by ndl
Wed Dec 19, 2018 7:12 pm
Forum: Polyhedra
Topic: New Torus
Replies: 9
Views: 2211

Re: New Torus

I found another interesting one yesterday:
J32 Torus.JPG
J32 Torus.JPG (30.31 KiB) Viewed 1938 times
This is a J91+J63 Tunnel through a J32 (Pentagonal Orthocupolarontunda)

I realized then that J32 had a cross section of 2 of those irregular hexagons that Stewart talked about inside a Rhombicosidodecahedron.
by ndl
Thu Nov 29, 2018 7:13 pm
Forum: Stella Forum
Topic: coloring for nets
Replies: 8
Views: 1532

Re: coloring for nets

Maybe you by accident selected "no tabs" in the menu? Do the tabs show up on the print preview?