react-native-arkit

react-native-arkit

React Native binding for iOS ARKit.

Tutorial: How to make an ARKit app in 5 minutes using React Native

Sample Project: https://github.com/HippoAR/ReactNativeARKit

Note: ARKit is only supported by devices with A9 or later processors (iPhone 6s/7/SE/8/X, iPad 2017/Pro) on iOS 11. You also need Xcode 9 to build the project.

There is a Slack group that anyone can join for help / support / general questions.

Join Slack

Getting started

$ yarn add react-native-arkit

make sure to use the latest version of yarn (>=1.x.x)

(npm does not work properly at the moment. See https://github.com/HippoAR/react-native-arkit/issues/103)

Mostly automatic installation

$ react-native link react-native-arkit

! Currently automatic installation does not work as PocketSVG is missing. Follow the manual installation

Manual installation

iOS

1. In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
2. Go to node_modules ➜ add react-native-arkit/ios/RCTARKit.xcodeproj and react-native-arkit/ios/PocketSVG/PocketSVG.xcodeproj
3. In XCode, in the project navigator, select your project. Add libRCTARKit.a and PocketSVG.framework to your project's Build Phases ➜ Link Binary With Libraries
4. In Tab General ➜ Embedded Binaries ➜ + ➜ Add PocketSVG.framework ios
5. Run your project (Cmd+R)<

iOS Project configuration

These steps are mandatory regardless of doing a manual or automatic installation:

1. Give permissions for camera usage. In Info.plist add the following:

<key>NSCameraUsageDescription</key>
<string>Your message to user when the camera is accessed for the first time</string>

1. ARKit only runs on arm64-ready devices so the default build architecture should be set to arm64: go to Build settings ➜ Build Active Architecture Only and change the value to Yes.

Usage

A simple sample React Native ARKit App

// index.ios.js

import React, { Component } from 'react';
import { AppRegistry, View } from 'react-native';
import { ARKit } from 'react-native-arkit';

export default class ReactNativeARKit extends Component {
  render() {
    return (
      <View style={{ flex: 1 }}>
        <ARKit
          style={{ flex: 1 }}
          debug
          // enable plane detection (defaults to Horizontal)
          planeDetection={ARKit.planeDetection.Horizontal}

          // enable light estimation (defaults to true)
          lightEstimationEnabled
          // get the current lightEstimation (if enabled)
          // it fires rapidly, so better poll it from outside with
          // ARKit.getCurrentLightEstimation()
          onLightEstimation={e => console.log(e.nativeEvent)}

          // event listener for (horizontal) plane detection
          onPlaneDetected={anchor => console.log(anchor)}

          // event listener for plane update
          onPlaneUpdated={anchor => console.log(anchor)}

          // arkit sometimes removes detected planes
          onPlaneRemoved={anchor => console.log(anchor)}

          // event listeners for all anchors, see [Planes and Anchors](#planes-and-anchors)
          onAnchorDetected={anchor => console.log(anchor)}
          onAnchorUpdated={anchor => console.log(anchor)}
          onAnchorRemoved={anchor => console.log(anchor)}

          // you can detect images and will get an anchor for these images
          detectionImages={[{ resourceGroupName: 'DetectionImages' }]}


          onARKitError={console.log} // if arkit could not be initialized (e.g. missing permissions), you will get notified here
        >
          <ARKit.Box
            position={{ x: 0, y: 0, z: 0 }}
            shape={{ width: 0.1, height: 0.1, length: 0.1, chamfer: 0.01 }}
          />
          <ARKit.Sphere
            position={{ x: 0.2, y: 0, z: 0 }}
            shape={{ radius: 0.05 }}
          />
          <ARKit.Cylinder
            position={{ x: 0.4, y: 0, z: 0 }}
            shape={{ radius: 0.05, height: 0.1 }}
          />
          <ARKit.Cone
            position={{ x: 0, y: 0.2, z: 0 }}
            shape={{ topR: 0, bottomR: 0.05, height: 0.1 }}
          />
          <ARKit.Pyramid
            position={{ x: 0.2, y: 0.15, z: 0 }}
            shape={{ width: 0.1, height: 0.1, length: 0.1 }}
          />
          <ARKit.Tube
            position={{ x: 0.4, y: 0.2, z: 0 }}
            shape={{ innerR: 0.03, outerR: 0.05, height: 0.1 }}
          />
          <ARKit.Torus
            position={{ x: 0, y: 0.4, z: 0 }}
            shape={{ ringR: 0.06, pipeR: 0.02 }}
          />
          <ARKit.Capsule
            position={{ x: 0.2, y: 0.4, z: 0 }}
            shape={{ capR: 0.02, height: 0.06 }}
          />
          <ARKit.Plane
            position={{ x: 0.4, y: 0.4, z: 0 }}
            shape={{ width: 0.1, height: 0.1 }}
          />
          <ARKit.Text
            text="ARKit is Cool!"
            position={{ x: 0.2, y: 0.6, z: 0 }}
            font={{ size: 0.15, depth: 0.05 }}
          />
          <ARKit.Light
            position={{ x: 1, y: 3, z: 2 }}
            type={ARKit.LightType.Omni}
            color="white"
          />
          <ARKit.Light
            position={{ x: 0, y: 1, z: 0 }}
            type={ARKit.LightType.Spot}
            eulerAngles={{ x: -Math.PI / 2 }}
            spotInnerAngle={45}
            spotOuterAngle={45}
            color="green"
          />
          <ARKit.Model
            position={{ x: -0.2, y: 0, z: 0, frame: 'local' }}
            scale={0.01}
            model={{
              scale: 1, // this is deprecated, use the scale property that is available on all 3d objects
              file: 'art.scnassets/ship.scn', // make sure you have the model file in the ios project
            }}
          />
          <ARKit.Shape
            position={{ x: -1, y: 0, z: 0 }}
            eulerAngles={{
              x: Math.PI,
            }}
            scale={0.01}
            shape={{
              // specify shape by svg! See https://github.com/HippoAR/react-native-arkit/pull/89 for details
              pathSvg: `
              <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
                <path d="M50,30c9-22 42-24 48,0c5,40-40,40-48,65c-8-25-54-25-48-65c 6-24 39-22 48,0 z" fill="#F00" stroke="#000"/>
              </svg>`,
              pathFlatness: 0.1,
              // it's also possible to specify a chamfer profile:
              chamferRadius: 5,
              chamferProfilePathSvg: `
                <path d="M.6 94.4c.7-7 0-13 6-18.5 1.6-1.4 5.3 1 6-.8l9.6 2.3C25 70.8 20.2 63 21 56c0-1.3 2.3-1 3.5-.7 7.6 1.4 7 15.6 14.7 13.2 1-.2 1.7-1 2-2 2-5-11.3-28.8-3-30.3 2.3-.4 5.7 1.8 6.7 0l8.4 6.5c.3-.4-8-17.3-2.4-21.6 7-5.4 14 5.3 17.7 7.8 1 .8 3 2 3.8 1 6.3-10-6-8.5-3.2-19 2-8.2 18.2-2.3 20.3-3 2.4-.6 1.7-5.6 4.2-6.4"/>
              `,
              extrusion: 10,
            }}
          />  
        </ARKit>
      </View>
    );
  }
}

AppRegistry.registerComponent('ReactNativeARKit', () => ReactNativeARKit);

<ARKit />-Component

Props

Prop	Type	Note
debug	Boolean	Debug mode will show the 3D axis and feature points detected.
planeDetection	ARKit.ARPlaneDetection.{ Horizontal | Vertical | HorizontalVertical | None }	ARKit plane detection. Defaults to Horizontal. Vertical is available with IOS 11.3
lightEstimationEnabled	Boolean	ARKit light estimation (defaults to false).
worldAlignment	ARKit.ARWorldAlignment.{ Gravity | GravityAndHeading | Camera }	ARWorldAlignmentGravity The coordinate system's y-axis is parallel to gravity, and its origin is the initial position of the device. ARWorldAlignmentGravityAndHeading The coordinate system's y-axis is parallel to gravity, its x- and z-axes are oriented to compass heading, and its origin is the initial position of the device. ARWorldAlignmentCamera The scene coordinate system is locked to match the orientation of the camera. Defaults to ARKit.ARWorldAlignment.Gravity. See
origin	{position, transition}	Usually {0,0,0} is where you launched the app. If you want to have a different origin, you can set it here. E.g. if you set origin={{position: {0,-1, 0}, transition: {duration: 1}}} the new origin will be one meter below. If you have any objects already placed, they will get moved down using the given transition. All hit-test functions or similar will report coordinates relative to that new origin as position. You can get the original coordinates with positionAbsolute in these functions
detectionImages	Array<DetectionImage>	An Array of DetectionImage (see below), only available on IOS 11.3

DetectionImage

An DetectionImage is an image or image resource group that should be detected by ARKit.

See https://developer.apple.com/documentation/arkit/arreferenceimage?language=objc how to add these images.

You will then receive theses images in onAnchorDetected/onAnchorUpdated. See also Planes and Anchors for more details.

DetectionImage has these properties

Prop	Type	Notes
resourceGroupName	String	The name of the resource group

We probably will add the option to load images from other sources as well (PRs encouraged).

Events

Event Name	Returns	Notes
onARKitError	ARKiterror	will report whether an error occured while initializing ARKit. A common error is when the user has not allowed camera access. Another error is, if you use worldAlignment=GravityAndHeading and location service is turned off
onLightEstimation	{ ambientColorTemperature, ambientIntensity }	Light estimation on every frame. Called rapidly, better use polling. See ARKit.getCurrentLightEstimation()
onFeaturesDetected	{ featurePoints}	Detected Features on every frame (currently also not throttled). Usefull to display custom dots for detected features. You can also poll this information with ARKit.getCurrentDetectedFeaturePoints()
onAnchorDetected	Anchor	When an anchor (plane or image) is first detected.
onAnchorUpdated	Anchor	When an anchor is updated
onAnchorRemoved	Anchor	When an anchor is removed
onPlaneDetected	Anchor	When a plane anchor is first detected.
onPlaneUpdated	Anchor	When a detected plane is updated
onPlaneRemoved	Anchor	When a detected plane is removed

See Planes and Anchors for Details about anchors

Planes and Anchors

ARKit can detect different anchors in the real world:

• plane horizontal and vertical planes
• image, image-anchors See DetectionImage
• face with iphone X or similar (not implemented yet)

You then will receive anchor objects in the onAnchorDetected, onAnchorUpdated, onAnchorRemoved callbacks on your <ARKit />-component.

You can use onPlaneDetected, onPlaneUpdated, onPlaneRemoved to only receive plane-anchors (may be deprecated later).

The Anchor object has the following properties:

Property	Type	Description
id	String	a unique id identifying the anchor
type	String	The type of the anchor (plane, image)
position	{ x, y, z }	the position of the anchor (relative to the origin)
positionAbsolute	{ x, y, z }	the absolute position of the anchor
eulerAngles	{ x, y, z }	the rotation of the plane

If its a plane-anchor, it will have these additional properties:

Property	Description
alignment	ARKit.ARPlaneAnchorAlignment.Horizontal or ARKit.ARPlaneAnchorAlignment.Vertical so you can check whether it was a horizontal or vertical plane
extent	see https://developer.apple.com/documentation/arkit/arplaneanchor?language=objc
center	see https://developer.apple.com/documentation/arkit/arplaneanchor?language=objc

image-Anchor:

Property	type	Description
image	{name}	an object with the name of the image.

Static methods

Static Methods can directly be used on the ARKit-export:

import { ARKit } from 'react-native-arkit'

//...
const result = await ARKit.hitTestSceneObjects(point);

All methods return a promise with the result.

Method Name	Arguments	Notes
snapshot
snapshotCamera		Take a screenshot without 3d models (will save to Photo Library)
getCameraPosition		Get the current position of the ARCamera
getCamera		Get all properties of the ARCamera
getCurrentLightEstimation		Get current light estimation { ambientColorTemperature, ambientIntensity}
getCurrentDetectedFeaturePoints		Get current detected feature points (in last current frame) (array)
focusScene		Sets the scene's position/rotation to where it was when first rendered (but now relative to your device's current position/rotation)
hitTestPlanes	point, type	check if a plane has ben hit by point ({x,y}) with detection type (any of ARKit.ARHitTestResultType). See https://developer.apple.com/documentation/arkit/arhittestresulttype?language=objc for further information
hitTestSceneObjects	point	check if a scene object has ben hit by point ({x,y})
isInitialized	boolean	check whether arkit has been initialized (e.g. by mounting). See https://github.com/HippoAR/react-native-arkit/pull/152 for details
isMounted	boolean	check whether arkit has been mounted. See https://github.com/HippoAR/react-native-arkit/pull/152 for details

3D-Components

General props

Most 3d object have these common properties

Prop	Type	Description
position	{ x, y, z }	The object's position (y is up)
scale	Number	The scale of the object. Defaults to 1
eulerAngles	{ x, y, z }	The rotation in eulerAngles
rotation	TODO	see scenkit documentation
orientation	TODO	see scenkit documentation
shape	depends on object	the shape of the object (will probably renamed to geometry in future versions)
material	{ diffuse, metalness, roughness, lightingModel, shaders }	the material of the object
transition	{duration: 1}	Some property changes can be animated like in css transitions. Currently you can specify the duration (in seconds).
renderingOrder	Number	Order in which object is rendered. Usefull to place elements "behind" others, although they are nearer.
categoryBitMask	Number / bitmask	control which lights affect this object
castsShadow	boolean	whether this object casts shadows
constraint	ARKit.Constraint.{ BillboardAxisAll | BillboardAxisX | BillboardAxisY | BillboardAxisZ | None }	Constrains the node to always point to the camera

New experimental feature:

You can switch properties on mount or onmount by specifying propsOnMount and propsOnUnmount. E.g. you can scale an object on unmount:

<ARKit.Sphere
  position={{x:0,y:0,z:0}}
  scale={1}
  transition={{duration: 1}}
  propsOnUnmount={{
    scale: 0
  }}
/>

Material

Most objects take a material property with these sub-props:

Prop	Type	Description
diffuse	{ ...mapProperties } (see below)	diffuse
specular	{ ...mapProperties } (see below)	specular
displacement	{ ...mapProperties } (see below)	displacement
normal	{ ...mapProperties } (see below)	normal
metalness	number	metalness of the object
roughness	number	roughness of the object
doubleSided	boolean	render both sides, default is true
litPerPixel	boolean	calculate lighting per-pixel or vertex litPerPixel
lightingModel	ARKit.LightingModel.*	LightingModel
blendMode	ARKit.BlendMode.*	BlendMode
fillMode	ARKit.FillMode.*	FillMode
shaders	Object with keys from ARKit.ShaderModifierEntryPoint.* and shader strings as values	Shader modifiers
colorBufferWriteMask	ARKit.ColorMask.*	color mask. Set to ARKit.ColorMask.None so that an object is transparent, but receives deferred shadows.

Map Properties:

Prop	Type	Description
path	string	Currently require is not supported, so this is an absolute link to a local resource placed for example in .xcassets
color	string	Color string, only used if path is not provided
wrapS	ARKit.WrapMode.{ Clamp | Repeat | Mirror }	wrapS
wrapT	ARKit.WrapMode.{ Clamp | Repeat | Mirror }	wrapT
wrap	ARKit.WrapMode.{ Clamp | Repeat | Mirror }	Shorthand for setting both wrapS & wrapT
translation	{ x, y, z }	Translate the UVs, equivalent to applying a translation matrix to SceneKit's transformContents
rotation	{ angle, x, y, z }	Rotate the UVs, equivalent to applying a rotation matrix to SceneKit's transformContents
scale	{ x, y, z }	Scale the UVs, equivalent to applying a scale matrix to SceneKit's transformContents

<ARKit.Box />

Prop	Type
shape	{ width, height, length, chamfer }

And any common object property (position, material, etc.)

<ARKit.Sphere />

Prop	Type
shape	{ radius }

<ARKit.Cylinder />

Prop	Type
shape	{ radius, height }

<ARKit.Cone />

Prop	Type
shape	{ topR, bottomR, height }

<ARKit.Pyramid />

Prop	Type
shape	{ width, height, length }

<ARKit.Tube />

Prop	Type
shape	{ innerR, outerR, height }

<ARKit.Torus />

Prop	Type
shape	{ ringR, pipeR }

<ARKit.Capsule />

Prop	Type
shape	{ capR, height }

<ARKit.Plane />

Prop	Type
shape	{ width, height }

Notice: planes are veritcally aligned. If you want a horizontal plane, rotate it around the x-axis.

Example:

This is a horizontal plane that only receives shadows, but is invisible otherwise:

<ARKit.Plane
    eulerAngles={{ x: Math.PI / 2 }}
    position={floorPlane.position}
    renderingOrder={9999}
    material={{
      color: '#ffffff',
      lightingModel: ARKit.LightingModel.Constant,
      colorBufferWriteMask: ARKit.ColorMask.None,
    }}
    shape={{
      width: 100,
      height: 100,
    }}
  />

<ARKit.Text />

Prop	Type
text	String
font	{ name, size, depth, chamfer }

<ARKit.Model />

SceneKit only supports .scn and .dae formats.

Prop	Type
model	{ file, node, scale, alpha }

Objects currently don't take material property.

<ARKit.Shape />

Creates a extruded shape by an svg path. See https://github.com/HippoAR/react-native-arkit/pull/89 for details

Prop	Type
shape	{ pathSvg, extrusion, pathFlatness, chamferRadius, chamferProfilePathSvg, chamferProfilePathFlatness }

<ARKit.Light />

Place lights on the scene!

You might set autoenablesDefaultLighting={false} on The <ARKit /> component to disable default lighting. You can use lightEstimationEnabled and ARKit.getCurrentLightEstimation() to find values for intensity and temperature. This produces much nicer results then autoenablesDefaultLighting.

Prop	Type	Description
position	{ x, y, z }
eulerAngles	{ x, y, z }
type	any of ARKit.LightType	see here for details
color	string	the color of the light
temperature	Number	The color temperature of the light
intensity	Number	The light intensity
lightCategoryBitMask	Number/bitmask	control which objects are lit by this light
castsShadow	boolean	whether to cast shadows on object
shadowMode	`ARKit.ShadowMode.*	Define the shadowmode. Set to ARKit.ShadowMode.Deferred to cast shadows on invisible objects (like an invisible floor plane)

Most properties described here are also supported: https://developer.apple.com/documentation/scenekit/scnlight

This feature is new. If you experience any problem, please report an issue!

HOCs (higher order components)

withProjectedPosition()

this hoc allows you to create 3D components where the position is always relative to the same point on the screen/camera, but sticks to a plane or object.

Think about a 3D cursor that can be moved across your table or a 3D cursor on a wall.

You can use the hoc like this:

const Cursor3D = withProjectedPosition()(({positionProjected, projectionResult}) => {
  if(!projectionResult) {
    // nothing has been hit, don't render it
    return null;
  }
  return (
    <ARKit.Sphere
      position={positionProjected}
      transition={{duration: 0.1}}
      shape={{
        radius: 0.1
        }}
    />
  )
})

It's recommended that you specify a transition duration (0.1s works nice), as the position gets updated rapidly, but slightly throttled.

Now you can use your 3D cursor like this:

Attach to a given detected horizontal plane

Given you have detected a plane with onPlaneDetected, you can make the cursor stick to that plane:

<Cursor3D projectPosition={{
  x: windowWidth / 2,
  y: windowHeight / 2,
  plane: "my-planeId"
  }}
/>

If you don't have the id, but want to place the cursor on a certain plane (e.g. the first or last one), pass a function for plane. This function will get all hit-results and you can return the one you need:

<Cursor3D projectPosition={{
  x: windowWidth / 2,
  y: windowHeight / 2,
  plane: (results) => results.length > 0 ? results[0] : null
  }}
/>

You can also add a property onProjectedPosition to your cursor which will be called with the hit result on every frame

It uses https://developer.apple.com/documentation/arkit/arframe/2875718-hittest with some default options. Please file an issue or send a PR if you need more control over the options here!

Attach to a given 3D object

You can attach the cursor on a 3D object, e.g. a non-horizontal-plane or similar:

Given there is some 3D object on your scene with id="my-nodeId"

<Cursor3D projectPosition={{
  x: windowWidth / 2,
  y: windowHeight / 2,
  node: "my-nodeId"
  }}
/>

Like with planes, you can select the node with a function.

E.gl you have several "walls" with ids "wall_1", "wall_2", etc.

<Cursor3D projectPosition={{
  x: windowWidth / 2,
  y: windowHeight / 2,
  node: results => results.find(r => r.id.startsWith('wall_')),
  }}
/>

It uses https://developer.apple.com/documentation/scenekit/scnscenerenderer/1522929-hittest with some default options. Please file an issue or send a PR if you need more control over the options here!

FAQ:

Which permissions does this use?

• camera access (see section iOS Project configuration above). The user is asked for permission, as soon as you mount an <ARKit /> component or use any of its API. If user denies access, you will get an error in onARKitError
• location service: only needed if you use ARKit.ARWorldAlignment.GravityAndHeading.

Is there an Android / ARCore version?

Not yet, but there has been a proof-of-concept: https://github.com/HippoAR/react-native-arkit/issues/14. We are looking for contributors to help backporting this proof-of-conept to react-native-arkit.

I have another question...

Join Slack!

Contributing

If you find a bug or would like to request a new feature, just open an issue. Your contributions are always welcome! Submit a pull request and see CONTRIBUTING.md for guidelines.