Skip to main content

Word Adventure, gather letters to complete the word!

This is an interactive installation that aims to combine learning words and fun in devising strategies to gather letters.


Collect letters to complete the word

The letters are dangling at various locations, and only the yellow colored characters can collect them. But these characters cannot jump that high, so players need to put blocks as stepping stones to help these cute yellow fellas to reach the letters. The blocks are generated by touching the screen (wall) and can be removed by touching it again.

System overview

The system is simply a projector and a laser range finder to detect touches on the wall. You may realize the black object in the photo above at the top of the wall. This is the laser range finder and for this project I used Hokuyo's UST10-LX. Content is developed with Unity.

How the touch detection works

Readings from the sensor

This image is the visualization of the data points detected. With the sensor placed on top of the wall looking down, if there are no hands touching the wall the laser beams will reach the floor. This will result in a rectangular shape with the floor points aligning as a straight line. However, if someone touches the wall, its position will be detected as shown in the above image. So to detect the touches we just have to first define the rectangular touch area, and all points that are within this area are touch (hand) points.

Limitations

There are some limitations in accuracy and detection rate. If there are two hands (touch points) that overlap each other from the sensor's point of view, the one on the outer side will not be detected.

Undetected touch point

As shown in the image,  the bottom touch point will not be detected because it is hidden by the other one above it. The black line represents the laser beam that sweeps the wall for obstacles (hand/touch points) and we can see it cannot reach the bottom point.



Comments

Post a Comment

Popular posts from this blog

Using FCM with the new HTTP v1 API and NodeJS

When trying to send FCM notifications I found out that Google has changed their API specifications. The legacy API still works but if you want to use the latest v1 API you need to make several changes. The list of changes is listed on their site so I won't be repeating them again but I'll just mention some of the things that caused some trial and error on my project. The official guide from Google is here : Official Migration Guide to v1 . The request must have a Body with the JSON containing the message data. Most importantly it needs to have "message" field which must contain the target of the notification. Usually this is a Topic, or Device IDs. Since my previous project was using GAS, my request had a field called "payload" instead of "body". Using the request from my previous project, my request in Node JS was as follows: request ({ url: 'https://fcm.googleapis.com/v1/projects/safe-door-278108/messages:send' , method: ...
Post a Comment
Read more

Object detection with Google Colab and Tensorflow

This is just a memo of the challenges I faced when running a model training on Google Colab, while following a great tutorial here . Mind the versions Tensorflow is currently at version 2.2.0 but most tutorials are still using the contrib package, and there is no known easy way to update the code to remove dependency on contrib. So my best bet is to downgrade the tensorflow version to 1.x. Since Google Colab only gives the options of either 1.x or 2.x and we cannot specify the exact version, I ended up with version 1.15.2. Even with the command :  %tensorflow_version  1.15.0 I ended up with : 1.15.2 Another pitfall was the version of numpy. Installing numpy gives us the version 1.18.3 but for some reason this generates the error : TypeError: 'numpy.float64' object cannot be interpreted as an integer Downgrading numpy to version 1.17.4 solved this for me. It seems we don't need ngrok for tensorboard With the command :  %load_ext tensorboard W...
Post a Comment
Read more

Microsoft Azure Face API and Unity

During one of my projects, I came across Microsoft's face recognition API (Azure Face API) and it looked good enough to recognize people's faces and detect if a person is a newcomer or a repeating customer to our store. As our installations mainly use the game engine Unity, I wanted to be able to use the Face API from Unity. Face API does not have an SDK for Unity but their requests are just HTTP requests so the Networking classes in Unity can be wrapped into methods to make it easy to call these APIs. First of all, to those who just want to see the code, here it is . My tests focus on the identification of a face in an input image. The full tutorial I followed can be found here . The Main scene goes through the steps in the tutorial such as creating a PersonGroup and adding Persons to the group if it is not created yet. Just make sure you: Change the API key. I used a free trial key which is no longer valid. Use whatever images you want. I don't mind you us...
Post a Comment
Read more