Qbr, pronounced as Cuber, is a webcam-based 3x3x3 rubik's cube solver written in Python 3 and OpenCV.
- ๐ Accurate color detection
- ๐ Accurate 3x3x3 rubik's cube detection
- ๐ Multilingual
Isn't the default color detection working out for you? Use the calibrate mode to let Qbr be familiar with your cube's color scheme. If your room has proper lighting then this will give you a 99.9% guarantee that your colors will be detected properly.
Simply follow the on-screen instructions and you're ready to go.
- Qbr
- Table of Contents
- Introduction
- Installation
- Usage
- Getting the solution
- Keybindings
- Parameters
- Example runs
- Inspirational sources
- License
The idea to create this came personally to mind when I started solving rubik's cubes. There were already so many professional programmers around the world who created robots that solve a rubik's cube in an ETA of 5 seconds and since 2016 in 1 second (link). That inspired me to create my own. I started using images only and eventually switched to webcam.
For linux users, make sure to install the following prerequisites:
$ sudo apt-get install python3-dev build-essential
Then, continue to install the project:
$ git clone --depth 1 https://github.com/kkoomen/qbr.git
$ cd qbr
$ python3 -m venv env
$ source ./env/bin/activate
$ pip3 install -r requirements.txt
Make sure you run source ./env/bin/activate
every time you want to run the
program.
Run Qbr:
$ ./src/qbr.py
This opens a webcam interface with the following things:
This is live preview mode displaying the detected colors.
This is the snapshot state. When pressing SPACE
it will create a snapshot in
order to show you what state it has saved. You can press SPACE
as many times
as you'd like if it has been detected wrong. The center piece color is used to
detect which side to save.
The bottom left corner shows the amount of sides scanned. This is so you
know if you've scanned in all sides before pressing ESC
.
This visualization represents the whole cube state that is being saved and can be used to confirm whether the whole cube state has been scanned successfully.
In the top right corner you can see the current interface language. If you want
to change the interface language you can press l
to cycle through them.
Continue to press l
until you've found the right language.
Default language is set to English.
Available languages are:
- English
- Hungarian
- Deutsch
- French
- Spanish
- Dutch
- ็ฎไฝไธญๆ
- ๅฐ็ฃ็น้ซไธญๆ
The default color scheme contains the most prominent colors for white, yellow, red, orange, blue and green. If this can't detect your cube its colors properly then you can use calibrate mode.
Press c
to go into calibrate mode in order to let Qbr be familiar with your
cube's color scheme. Simply follow the on-screen instructions and you're ready
to go.
Note: Your calibrated settings are automatically saved after you've calibrated your cube successfully. The next time you start Qbr it will automatically load it.
Tip: If you've scanned wrong, simple go out of calibrate mode by pressing c
and go back into calibrate by pressing c
again.
Qbr checks if you have filled in all 6 sides when pressing ESC
. If so, it'll
calculate a solution if you've scanned it correctly.
You should now see a solution (or an error if you did it wrong).
There is a strict way of scanning in the cube. Qbr will detect the side automatically, but the way you rotate the cube during the time you're scanning it is crucial in order for Qbr to properly calculate a solution. Make sure to follow the steps below properly:
- Start off with the
green
side facing the camera andwhite
on top,green
being away from you. Start by scanning in thegreen
side at this point. - After you've scanned in the
green
side, rotate the cube 90 or -90 degrees horizontally. It doesn't matter if you go clockwise or counter-clockwise. Continue to do this for thegreen
,blue
,red
andorange
sides until you are back at thegreen
side. - You should now be in the same position like you started, having
green
facing the camera andwhite
on top. Rotate the cube forward 90 degrees, resulting ingreen
at the bottom andwhite
facing the camera. Start scanning in thewhite
side. - After you've scanned the
white
side, turn the cube back to how you started, havinggreen
in front again andwhite
on top. Now rotate the cube backwards 90 degrees, resulting ingreen
on top andyellow
facing the camera. Now you can scan in the lastyellow
side.
If you've done the steps above correctly, you should have a solution from Qbr.
-
SPACE
for saving the current state -
ESC
quit -
c
toggle calibrate mode -
l
switch interface language
You can use -n
or --normalize
to also output the solution in a "human-readable" format.
For example:
R
will be:Turn the right side a quarter turn away from you.
F2
will be:Turn the front face 180 degrees.
$ ./qbr.py
Starting position:
front: green
top: white
Moves: 20
Solution: U2 R D2 L2 F2 L U2 L F' U L U R2 B2 U' F2 D2 R2 D2 R2
$ ./qbr.py -n
Starting position:
front: green
top: white
Moves: 20
Solution: B2 U2 F' R U D' L' B' U L F U F2 R2 F2 D' F2 D R2 D2
1. Turn the back side 180 degrees.
2. Turn the top layer 180 degrees.
3. Turn the front side a quarter turn to the left.
4. Turn the right side a quarter turn away from you.
5. Turn the top layer a quarter turn to the left.
6. Turn the bottom layer a quarter turn to the left.
7. Turn the left side a quarter turn away from you.
8. Turn the back side a quarter turn to the right.
9. Turn the top layer a quarter turn to the left.
10. Turn the left side a quarter turn towards you.
11. Turn the front side a quarter turn to the right.
12. Turn the top layer a quarter turn to the left.
13. Turn the front side 180 degrees.
14. Turn the right side 180 degrees.
15. Turn the front side 180 degrees.
16. Turn the bottom layer a quarter turn to the left.
17. Turn the front side 180 degrees.
18. Turn the bottom layer a quarter turn to the right.
19. Turn the right side 180 degrees.
20. Turn the bottom layer 180 degrees.
Special thanks to HaginCodes for the main inspiration on how to improve my color detection.
https://github.com/HaginCodes/3x3x3-Rubiks-Cube-Solver
http://programmablebrick.blogspot.com/2017/02/rubiks-cube-tracker-using-opencv.html
https://gist.github.com/flyboy74/2cc3097f784c8c236a1a85278f08cddd
https://github.com/dwalton76/rubiks-color-resolver
Qbr is licensed under the MIT License.