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Announcing MoStella! Mobile app full of polyhedra.

Posted: Sat Aug 24, 2013 3:06 pm
by robertw
Hi folks,

I've finally finished my polyhedral mobile app MoStella. It's Android-only at the moment.

MoStella can display polyhedra, their duals, and show animations of polyhedra morphing into their duals and back in a couple of different ways. You can also explode faces apart to better see inside, and flag your favourites for quick access later. Rotate models in 3D with a swipe of the finger, or limit to single-axis rotation, and release your finger while still moving to let the model keep rotating continuously.

MoStella comes in 3 flavours, depending on which polyhedra are included (the free version also has ads at the top).

MoStella Free: Platonic solids, Kepler-Poinsot and Archimedean solids. ... StellaFree

MoStella Silver: adds all the remaining uniform polyhedra to the mix, including a selection of prisms and antiprisms. ... ellaSilver

MoStella Gold: adds lots of additional sets of polyhedra: Johnson solids, Stewart toroids, The 59 Icosahedra, stellations, compounds, geodesic spheres, Waterman polyhedra and more. ... StellaGold

The apps can also display some info about each shape, with a link to my paper model online where applicable.

Have fun!

Re: Announcing MoStella! Mobile app full of polyhedra.

Posted: Sun Oct 07, 2018 10:50 am
by guy
Hi Rob,

Just been playing with MoStella Free, so I thought I'd drop you a line. First time in many years that I have had a box to run one of your apps on natively, this time a Planet Gemini PDA running Android. Thoughts follow in random order:

In faces+wireframe view, the frame tends to disappear along non-convex edges, such as on the Kepler-Poinsot stars. It's erratic and could confuse the novice most likely to be using the app.

Like most netbook-style machines, my Gemini has a landscape-oriented screen. Being a pocket device, it is a typical modern smartphone screen with 2:1 aspect ratio. MoStella does not recognise the orientation and I have to hold it sideways, like reading a book. Chromebooks are beginning to sell to schools in large numbers and they also now run Android apps. On these, MoStella opens just in the middle of the screen, it looks clunky and much of the visual impact is lost. It would be nice if you could offer a landscape-optimised display option, and downright brilliant if it could adapt dynamically to the screen orientation.

Is there any way to remove a polyhedron from my Favourites list, once it has been added there? If not, it would be a thoughtful update.

I don't know if your Gold version allows file import or export, but it would be a useful feature for more advanced users. Could just import .stel files saved from the desktop version, ideally it would also accept .off. Bitmap image export would also be good. Would mean it could be used for real creative work and sharing creations/discoveries. A passing thought on implementation, since this is a mobile version you could assume Internet connectivity and provide import/export filters and similar functions as web/cloud based services rather than in-app bloatware. A file storage cloud for automatic instant access on any device and sharing with other Stella users, i.e. just appearing on the list of polyhedra available, would be cool. I do not think it should be too hard either, as my Gemini has an Agenda app written for it, with a similar cloud functionality built-in.

I find it difficult to set a very gentle rotation rate, the "sticky" zone for stopping it dead is a bit too coarse for me. But I can appreciate the need for kids to have it robust. At the other end of the scale, ridiculously high speeds are very easily triggered but not very useful. Could you do something like slowing the rotation to a half or a quarter of its present rate?

Re: Announcing MoStella! Mobile app full of polyhedra.

Posted: Sun Oct 07, 2018 12:24 pm
by robertw
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 (and in a different language). I want to do that some day, but for now I can't make any simple tweaks to the existing app.

If I do rewrite it, then it will handle landscape & portrait.

Also, this shares no code really with desktop Stella. I wouldn't easily be able to make it load .stel files.

You CAN remove shapes from the favourites folder though. Select the shape from the favourites list and you'll see a gold star on the toolbar at the bottom. Click it to remove it from the favourites. It will go back to grey.

Re: Announcing MoStella! Mobile app full of polyhedra.

Posted: Fri Nov 02, 2018 3:27 pm
by guy
Thanks for the heads-up, Rob.