8 ms·

Show HN: WanderApp – Cast Harry Potter Spells with gyroscope data

80 points by corupta 5y ago

corupta 5y ago
Hi, there. On last weekend we entered a Hackathon, and come up with this new technology. Using gyroscope data, we can pretty much use the mobile phones as a laser pointer and draw. We created a React-Native(Expo) app in which you try to imitate spell drawings by moving/rotating your phone. The project is open-source, we haven't put it on app/play stores but you can build and install on your phones to try it out following the readme. You can check out more details and how it works in the project readme. Also, there's a voting period of the Hackathon until wednesday. If you like the project, please vote us on https://ucbuyucuturnuvasi.com/grimmauld-meydani https://ucbuyucuturnuvasi.com/grimmauld-meydani You can also, check out other awesome projects there.
sweetheart 5y ago
I love this. I originally got into programming because I figured it was the closest thing to the magic I loved in Harry Potter: a mixture of academia, history, and pragmatism. Seeing a project like this just embodies a lot of the sense of wonder I had about getting computers to do cool new things for me. Thanks for making something purely for fun and sharing it with us!
- robalni 5y ago
  Programming really is like magic. In Harry Potter: You say magic words, that make things happen. In programming: You type words in the computer, that make things happen.
  - kingcharles 5y ago
    We even have magic numbers! https://en.wikipedia.org/wiki/Magic_number_(programming) https://en.wikipedia.org/wiki/Magic_number_(programming)
mschuster91 5y ago
Awesome. I wonder if it could also detect and judge pronounciation of a spell - always remember: "It's leviOsa, not levioSA!"
- okaygenc 5y ago
  Due to Hackathon rules, we cannot update the repo until December 16th. After December 16, we will publish on expo and make new feature announcements.
  - eloeffler 5y ago
    No sorcery during summer breaks then, huh :)
lcrz 5y ago
This is full of copyright infringement. If you don't want your app to be DMCA'd I'd suggest you remove all references to Harry Potter.
- tibanne 5y ago
  Does it matter if they aren't selling anything?
  - grenoire 5y ago
    Nintendo sends cease and desists to a lot of free (as in beer or speech) projects. Some companies bully hard, I think Warner Bros is likely heavy-handed on Harry Potter.
  - moffkalast 5y ago
    Depends if it falls under fair use or not.
- charcircuit 5y ago
  Have similar things been DMCA'd before? It's very possible this just gets overlooked.
- curiousgal 5y ago
  Ya girl JK filed a report against a woman who happened to have the same last name as one of her characters so yeah. https://mobile.twitter.com/gothspiderbitch/status/1467693856690868228 https://mobile.twitter.com/gothspiderbitch/status/1467693856...
  - tzs 5y ago
    The report wasn't for having the same last name as an HP character. It was for a photo of Hogwarts that was being used commercially.
- tzs 5y ago
  Rowling is OK with fan-based HP writing if it isn't commercial, isn't obscene, and is not credited to whoever produced it and not to her [1]. There's probably a decent chance she would be OK with this if it is free. [1] https://fanlore.org/wiki/Rowling_backs_Potter_fan_fiction https://fanlore.org/wiki/Rowling_backs_Potter_fan_fiction
Moosdijk 5y ago
Nice. We did the same for a uni project back in the day, but with a dedicated imu and an arduino uno.
Gobookmart1 5y ago
https://gobookmart.com/google-play-books-vs-amazon-kindle-direct-publishing/ https://gobookmart.com/google-play-books-vs-amazon-kindle-di...
pddpro 5y ago
Years ago I had an idea. A game of magic battles. The witches and wizards would search the vicinity (very much like Pokemon go) to find other witches and wizards, challenge them to a duel and fight it out with their wands (or smartphones). The spells would be triggered by using movements i.e. gyroscopes and trickier spells would require lots of wand waving and verbal cues. I suppose when AR/VR glasses becomes the norm, we could also integrate the magical beams and cooler effects! Anyways, it brings me so much joy to see a portion of it materialize. I'll just patiently wait until someone comes up with the entire game
danhoule 5y ago
I do think that you should play it safe on this one as they might DMCA the project.
ramesh31 5y ago
Image similarity is a terrible way to do this; you lose all temporal data, which would make different speeds of motion impossible to discern. You're much better off feeding your XYZ + timeseries data into a hidden markov model, then classifying gestures with SVM prediction. There's a really great C++ gesture recognition library that I've used to do just that for a VR game that featured custom spellcasting gestures [0] [0] https://github.com/nickgillian/grt https://github.com/nickgillian/grt
- corupta 5y ago
  Hi, I totally agree, but I had like 1-2 hours left to implement the similarity check part, so I took a simple image similarity approach. (Also, I only have images for target spells for now, need to create target data with temporal data as well) Your idea for gesture recognition is interesting, I will look into that in more detail. PS: I already convert 3D to 2D with filtering so I can apply comparison of 2 2D+time data: What, I originally had in my mind was to modify and use a similarity metric such as EMD (Earth Mover’s Distance) which I believe would be a great fit for our case.

80 points by corupta 5y ago

Hi, there. On last weekend we entered a Hackathon, and come up with this new technology. Using gyroscope data, we can pretty much use the mobile phones as a laser pointer and draw. We created a React-Native(Expo) app in which you try to imitate spell drawings by moving/rotating your phone. The project is open-source, we haven't put it on app/play stores but you can build and install on your phones to try it out following the readme. You can check out more details and how it works in the project readme. Also, there's a voting period of the Hackathon until wednesday. If you like the project, please vote us on https://ucbuyucuturnuvasi.com/grimmauld-meydani https://ucbuyucuturnuvasi.com/grimmauld-meydani You can also, check out other awesome projects there.

sweetheart 5y ago

I love this. I originally got into programming because I figured it was the closest thing to the magic I loved in Harry Potter: a mixture of academia, history, and pragmatism. Seeing a project like this just embodies a lot of the sense of wonder I had about getting computers to do cool new things for me. Thanks for making something purely for fun and sharing it with us!

robalni 5y ago
Programming really is like magic. In Harry Potter: You say magic words, that make things happen. In programming: You type words in the computer, that make things happen.
- kingcharles 5y ago
  We even have magic numbers! https://en.wikipedia.org/wiki/Magic_number_(programming) https://en.wikipedia.org/wiki/Magic_number_(programming)

mschuster91 5y ago

Awesome. I wonder if it could also detect and judge pronounciation of a spell - always remember: "It's leviOsa, not levioSA!"

okaygenc 5y ago
Due to Hackathon rules, we cannot update the repo until December 16th. After December 16, we will publish on expo and make new feature announcements.
- eloeffler 5y ago
  No sorcery during summer breaks then, huh :)

lcrz 5y ago

This is full of copyright infringement. If you don't want your app to be DMCA'd I'd suggest you remove all references to Harry Potter.

tibanne 5y ago
Does it matter if they aren't selling anything?
- grenoire 5y ago
  Nintendo sends cease and desists to a lot of free (as in beer or speech) projects. Some companies bully hard, I think Warner Bros is likely heavy-handed on Harry Potter.
- moffkalast 5y ago
  Depends if it falls under fair use or not.
charcircuit 5y ago
Have similar things been DMCA'd before? It's very possible this just gets overlooked.
curiousgal 5y ago
Ya girl JK filed a report against a woman who happened to have the same last name as one of her characters so yeah. https://mobile.twitter.com/gothspiderbitch/status/1467693856690868228 https://mobile.twitter.com/gothspiderbitch/status/1467693856...
- tzs 5y ago
  The report wasn't for having the same last name as an HP character. It was for a photo of Hogwarts that was being used commercially.
tzs 5y ago
Rowling is OK with fan-based HP writing if it isn't commercial, isn't obscene, and is not credited to whoever produced it and not to her [1]. There's probably a decent chance she would be OK with this if it is free. [1] https://fanlore.org/wiki/Rowling_backs_Potter_fan_fiction https://fanlore.org/wiki/Rowling_backs_Potter_fan_fiction

Moosdijk 5y ago

Nice. We did the same for a uni project back in the day, but with a dedicated imu and an arduino uno.

Gobookmart1 5y ago

https://gobookmart.com/google-play-books-vs-amazon-kindle-direct-publishing/ https://gobookmart.com/google-play-books-vs-amazon-kindle-di...

pddpro 5y ago

Years ago I had an idea. A game of magic battles. The witches and wizards would search the vicinity (very much like Pokemon go) to find other witches and wizards, challenge them to a duel and fight it out with their wands (or smartphones). The spells would be triggered by using movements i.e. gyroscopes and trickier spells would require lots of wand waving and verbal cues. I suppose when AR/VR glasses becomes the norm, we could also integrate the magical beams and cooler effects! Anyways, it brings me so much joy to see a portion of it materialize. I'll just patiently wait until someone comes up with the entire game

danhoule 5y ago

I do think that you should play it safe on this one as they might DMCA the project.

ramesh31 5y ago

Image similarity is a terrible way to do this; you lose all temporal data, which would make different speeds of motion impossible to discern. You're much better off feeding your XYZ + timeseries data into a hidden markov model, then classifying gestures with SVM prediction. There's a really great C++ gesture recognition library that I've used to do just that for a VR game that featured custom spellcasting gestures [0] [0] https://github.com/nickgillian/grt https://github.com/nickgillian/grt

corupta 5y ago
Hi, I totally agree, but I had like 1-2 hours left to implement the similarity check part, so I took a simple image similarity approach. (Also, I only have images for target spells for now, need to create target data with temporal data as well) Your idea for gesture recognition is interesting, I will look into that in more detail. PS: I already convert 3D to 2D with filtering so I can apply comparison of 2 2D+time data: What, I originally had in my mind was to modify and use a similarity metric such as EMD (Earth Mover’s Distance) which I believe would be a great fit for our case.