ar-location-based-android: This AR app generally show where things are in the real-world by indicating where the app thinks they are over the camera view when the user holds the phone up and moves it about.

fork from ： https://github.com/dat-ng/ar-location-based-android

# AR Location-based for Android
This AR app generally show where things are in the real-world by indicating where the app thinks they are over the camera view when the user holds the phone up and moves it about.

### Theoretical base
**Augmented Reality** will transfer real coordinates system to camera coordinates system. In AR Location-based, the real coordinate is [Geographic coordinate system] (https://en.wikipedia.org/wiki/Geographic_coordinate_system).
We will convert the **GPS coordinate (Latitude, Longitude, Altitude)** to **Navigation coordinate (East, North, Up)**, then transfer **Navigation coordinate** to **Camera coordinate** and display it on camera view.

### GPS coordinate to Navigation coordinate
There are two steps:

1. Convert GPS coordinate to ECEF coordinate (Earth-centered Earth-fixed coordinate): 
2. Convert ECEF coordinate to Navigation coordinate

[Here is PDF file about convert GPS coordinate to Navigation coordinate.](http://digext6.defence.gov.au/dspace/bitstream/1947/3538/1/DSTO-TN-0432.pdf)

###ENU coordinate to Camera coordinate

To convert **ENU coordinate** to **Camera coordinate**, we will multiply camera projection matrix with ENU coordinate vector, the result is a vector [v0, v1, v2, v3].

Then x = (0.5 + v0 / v3) * widthOfCameraView and y = (0.5 - v1 / v3) * heightOfCameraView.

**ENU coordinate vector:** [n -e u 1]

**Camera projection matrix** is result of **Original camera projection matrix** and **Rotation matrix** multiplying

**Original camera projection matrix:**

![alt text](./perspMatrix.png)

**Rotation matrix**: you can get this value by using Android sensors

### Demo
![alt text](./AR-Demo.png)

asdtiang/ar-location-based-android

简介

发行版

贡献者

近期动态

asdtiang/ar-location-based-android .gitee-modal { width: 500px !important; }

简介

发行版

贡献者

近期动态

搜索帮助

asdtiang/ar-location-based-android