Saw the Numberphile video about the Herschel enneahedron and thought I'd make one in Stella.

https://www.youtube.com/watch?v=3X2aQIMx5bs

Turned out to be pretty easy. Here are the steps.

(1) Start with a triangular prism. You can do this by hitting Ctrl+N (or "File->Polyhedron List" from the menu ...

Ah sorry, I see. Hmm, is it important? I'm not sure why it ends up different, just something being done in a different order, but it does end up with a valid colouring. There's nothing really "correct" about the original colouring. When changing back to the original symmetry, it's kind of free to ...

Nope, not a mistake. The model is recoloured according to the new symmetry. It means that under tetrahedral symmetry, not all squares can be transformed to align with all the other squares.

If you want to maintain the initial colouring though, you can disable "Options->Recolor Sub-symmetries ...

Nope, no list yet. One of the boring admin things I still need to work on will be a list of updates, as well as the documentation, website etc. Yes there's lots of changes, but a lot of time was spent fixing bugs and getting it working with the latest dev tools (the last version was built using dev ...

It's a good idea, but I probably won't get it done before the next release. Maybe a minor release after that.

I imagine fly mode and rotate-around-camera mode would go together wouldn't they? One toggle would change both?

There's lots of possibilities, like moving mouse controls forward linear ...

As it happens, I've already added this as an option for the next version.

For now, the anti-aliasing can be avoided by changing "Over-sampling" to 1 in the export dialog.

OK, NOOOOW I've finally got all the types working, as far as I can tell, for cells, faces, edges and vertices. I made some tests to run through every 4D uniform polytopes (plus others polychora in the library) and do some tests, like confirming that the types identified match between base and dual ...

Seems to be a common mistake, but that page is by Robert Austin, who uses Stella, but this Stella forum and Stella itself are by me, Robert Webb.

So I'm not sure how he made that model, although you may be able to do it by creating a geodesic sphere from an icosahedron and then using faceting mode ...

You can use the "Edit->Put Model in Memory" submenu to pick a slot to save it to (or keyboard shortcut "m"). Then load other model. Then combine them with "Edit->Add/Blend from Memory".

If they have the same symmetry, then they should align well. If not, your milage may vary.

Sorry yes 2191. I was forgetting the highest number wasn't in Cat 30. But don't worry, I've got them too.

Currently Stella4D only has 4D compounds that can be generated from their vertex figures in the library, although yes you can bring them in via OFF if one is created outside.

I've now got every known uniform polyhedron added to Stella4D's library for the next release, including all the new ones, all the way up to 2188! And all the vertex figures work now (some of the new ones had issues initially).

The folder you linked to is missing a lot still. Cat 29 only has 2 out ...

I've got it working for all the test cases you've given now. Spittid and spiddit are 3, 9, 4, 1 (cell types, face types, edge types, vert types). J37 prism is 5, 9, 7, 2. Siggissido is 5, 9, 6, 1.

It still can't distinguish chiral pairs or types in a compound. Those will probably have to wait.

Did you borrow Miratope's algorithm to improve 4D element type calculation?

No, I have no intention of looking at how Miratope does anything. Frankly it would be much harder trying to understand someone else's code than just doing it myself. This has been on my to-do list for many years along ...

J37 is easy enough to build in Stella4D. Load J37 then use "4D->Create 4D Prism on Current Polyhedron".

Maybe your instinct is better, but it's not immediately obvious to me when it gets types wrong, eg in spittid. Takes me some playing around to see the pentagonal prisms come in two types. So ...

Can you provide examples other than spittid? Need examples in order to fix things.