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https://github.com/ahmedalmasri/worldmotion

The coordinate system that represents device motion or position relative to the Earth
https://github.com/ahmedalmasri/worldmotion

3d coremotion ios realworld sensormanager swift

Last synced: 3 months ago
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The coordinate system that represents device motion or position relative to the Earth

Host: GitHub
URL: https://github.com/ahmedalmasri/worldmotion
Owner: ahmedAlmasri
License: mit
Created: 2021-04-21T20:18:49.000Z (almost 4 years ago)
Default Branch: master
Last Pushed: 2021-05-11T23:34:40.000Z (over 3 years ago)
Last Synced: 2024-11-10T21:04:00.882Z (3 months ago)
Topics: 3d, coremotion, ios, realworld, sensormanager, swift
Language: Swift
Homepage:
Size: 12.3 MB
Stars: 17
Watchers: 3
Forks: 6
Open Issues: 0
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

        # 🌏 WorldMotion 🧘🏼 (beta)

Use a CoreMotion sensor to use a coordinate system that represents device motion or position relative to the Earth. In this coordinate system:

- y points to magnetic north along the surface of the Earth.

- x is 90 degrees from y , pointing approximately east.

- z extends up into space. Negative z extends down into the ground



  



[![CI Status](https://img.shields.io/travis/[email protected]/WorldMotion.svg?style=flat)](https://travis-ci.org/[email protected]/WorldMotion)

[![Version](https://img.shields.io/cocoapods/v/WorldMotion.svg?style=flat)](https://cocoapods.org/pods/WorldMotion)

[![License](https://img.shields.io/cocoapods/l/WorldMotion.svg?style=flat)](https://cocoapods.org/pods/WorldMotion)

[![Platform](https://img.shields.io/cocoapods/p/WorldMotion.svg?style=flat)](https://cocoapods.org/pods/WorldMotion)

## Determining device orientation

Device orientation is the position of the device in space relative to the Earth's coordinate system (specifically, to the magnetic north pole).

The `getRotationMatrix()` method generates a rotation matrix from the accelerometer and geomagnetic field sensor. A rotation matrix is a linear algebra concept that translates the sensor data from one coordinate system to another—in this case, from the device's coordinate system to the Earth's coordinate system.

The `getOrientation()` method uses the rotation matrix to compute the angles of the device's orientation. All of these angles are in radians, with values from -π to π. There are three components to orientation:

*Azimuth* : The angle between the device's current compass direction and magnetic north. If the top edge of the device faces magnetic north, the azimuth is 0.



  



*Pitch* : The angle between a plane parallel to the device's screen and a plane parallel to the ground.



  



*Roll* : The angle between a plane perpendicular to the device's screen and a plane perpendicular to the ground.



  



>Note: orientation angles use a different coordinate system than the one used in aviation (for yaw, pitch, and roll). In the aviation system, the x -axis is along the long side of the plane, from tail to nose.

# Use case

Let's assume that you want to know the angle of rotation around a certain object in the real world, so you need the value `x` from the Earth's coordinate system.

1. Convert a rotation vector to a rotation matrix.

```Swift

  let matrixFromVector = rotationMatrix.getRotationMatrixFromVector()

```

2. Rotating the supplied rotation matrix so it is expressed in a different coordinate system using.

```Swift

 let coordinateMatrix = matrixFromVector.coordinateSystem(CMRotationMatrix.axisX, CMRotationMatrix.axisY)

```

3. Compute the device's orientation based on the rotation matrix.

```Swift

 let acceleration = coordinateMatrix.getOrientation()

```

> The return values is a radius that needs to be converted into degrees using `toDegrees`

##### Output



  



## Using

- EarthCoordinate:

```Swift

let earthCoordinate = EarthCoordinate()

// .......

deinit {

    earthCoordinate.stop()

}

 override func viewDidAppear(_ animated: Bool) {

        super.viewDidAppear(animated)

    earthCoordinate.delegate = self

    earthCoordinate.start(interval: 0.2, queue: .init())

 }

 // MARK: -  EarthCoordinate delegate

extension ViewController: EarthCoordinateDelegate {

   func onOrientationChange(x: Double, y: Double, z: Double) {

       // ..... calculate value degrees

    }

}

```

- RotationMatrix

```Swift

let rotationMatrix = deviceMotion.attitude.rotationMatrix

let matrixFromVector = rotationMatrix.getRotationMatrixFromVector()

let coordinateMatrix = safeSelf.getCoordinateSystem(with: matrixFromVector)

let acceleration = coordinateMatrix.getOrientation()

```

## Example

To run the example project, clone the repo, and run `pod install` from the Example directory first.

## Requirements

- Swift 4.2+

- Xcode 10.0+

- iOS 11.0+

## Installation

WorldMotion is available through [CocoaPods](https://cocoapods.org). To install

it, simply add the following line to your Podfile:

```ruby

pod 'WorldMotion'

```

## Author

Ahmad Almasri, [email protected]

## License

WorldMotion is available under the MIT license. See the LICENSE file for more info.