# AprilTag Marker Tracking in Unity

## Survey source

1. April Tag: https://april.eecs.umich.edu/software/apriltag
2. OpenMV(official): https://openmv.io/
3. OpenMV(CN): https://book.openmv.cc/image/apriltag.html
4. Unity Package: https://github.com/keijiro/jp.keijiro.apriltag

---

## Support system:
Windows (x86-64), macOS (x86-64), Linux (x86-64), iOS (arm64), Android (arm64)

## Environment

1. OS: Windows11
2. Unity Editor: 2021.3.7f1
3. Keijiro/AprilTag: 1.0.2
4. Keijiro/Test Tools: 1.0.4

## Prepare Apriltag
1. TagDetector component only supports the `tagStandard41h12`.

2. Download `tagStandard41h12` from the repo:
https://github.com/AprilRobotics/apriltag-imgs

3. Use imagemagick to rescale image.
https://imagemagick.org/script/index.php

4. Scale image commond line:

https://github.com/AprilRobotics/apriltag-imgs
![](https://i.imgur.com/Chr46XY.png)

5. Result:
Convert Tag-0 ![](https://i.imgur.com/8RrLFVK.png) to ![](https://i.imgur.com/ZWo4Dbl.png)
Convert Tag-66 ![](https://i.imgur.com/XGREbMn.png) to ![](https://i.imgur.com/JlR7XmO.png)


## Tracking apriltag in Unity

1. Setup scoped registrise
![](https://i.imgur.com/7XnPmZh.png)

2. Package Manager/Packages: My Registries/
Import `AprilTag` and `Test Tools`.
![](https://i.imgur.com/QbOYgk4.png)

3. Open Scene `DetectionTest`

4. Drop test video into project.

5. Change `Source Type` to `Video` on inspector and run project. 
Or choose sources type to Webcam.
![](https://i.imgur.com/HUTQ6Wx.png)

6. Result
![](https://i.imgur.com/uqT7CLE.gif)
![](https://i.imgur.com/DMb2hgJ.gif)