This repository developed in Native Android - Java demonstrates how to place objects & draw routes between them in ARCore scene using Latitude & Longitude. The code doesn't require any use of Google Geospatial API or any such library.
Developed by: Bhaskar Kaura (https://www.linkedin.com/in/bhaskar-kaura-300b09272/)
This app uses ARCore with Sceneform to support AR & render objects in AR World. The current location of user is continuously calculated and also the yaw(azimuth) aka the rotation of the device around it's -z axis which is respective to north. Now, we have our current Latitude, Longitude & our rotation so we assume that we are an origin point on graph (0,0) and we added a Latitude & Longitude of a coordinate into the graph say it's (3,3). So, we convert this (3,3) via a CoordinateHelper class which converts LatLng into local coordinates using our current location, yaw and the target Location. Now we got the local coordinates, we set this as a LocalPosition to our AnchorNode in AR World.
This solution is pretty accurate as it doesnt rely on any external system and just requires user location & yaw. But, keep in mind that if the location LatLng & yaw of user is incorrect or inaccurate, then this may affect the resulted coordinates.
Anchor placed in AR World using LatLng
Route lines draw between different LatLng in AR World
- Get current user location & yaw
- Convert entered Latitude & Longitude into local coordinates
- Place anchor & object on LatLng using coordinate converter in AR Scene
- Draw routes between different LatLng using coordinate converter in AR Scene
implementation ('es.situm:situm-sdk:2.85.3@aar') {
transitive = true
}
implementation 'com.google.android.gms:play-services-maps:18.1.0'
implementation 'com.google.ar.sceneform.ux:sceneform-ux:1.17.1'
implementation 'com.github.appoly:ARCore-Location:1.2'
implementation 'com.google.android.gms:play-services-location:21.0.1'
implementation 'de.javagl:obj:0.2.1'
implementation 'com.google.ar:core:1.31.0'
implementation 'com.google.ar.sceneform:core:1.17.1'
Using the code below, retrieve & update the current user location
private LatLng currentLatLng =
new LatLng(0, 0);
private LocationManager locationManager;
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0L, (float) 0, new LocationListener() {
@Override
public void onLocationChanged(@NonNull Location location) {
// this location LatLng can be highly inaccurate if being used in indoor location
// or places where it's hard to navigate, it is suggested to use special
// navigation systems like indoor navigation system for accurate results.
// this inaccurate latlng can affect the coordinates of poi anchors, for testing
// try with a fixed current latlng on which you are currently placed.
currentLatLng = new LatLng(location.getLatitude(), location.getLatitude());
binding.instrText.setText("Place your camera slightly next to your foot and tap on the
floor shadow to begin!");
}
});
Using the code below, retrieve the device yaw or the azimuth
private float I[] = null; //for magnetic rotational data
private float accels[] = new float[3];
private float mags[] = new float[3];
private float[] values = new float[3];
private float yaw;
private float pitch;
private float roll;
private SensorManager sensorManager;
private Sensor sensor;
//sensor manager & sensor required to calculate yaw
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
sensor = sensorManager.getDefaultSensor(Sensor.TYPE_GEOMAGNETIC_ROTATION_VECTOR);
Inside OnResume() :
Sensor accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
if (accelerometer != null) {
sensorManager.registerListener(this, accelerometer,
SensorManager.SENSOR_DELAY_NORMAL, SensorManager.SENSOR_DELAY_UI);
}
Sensor magneticField = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
if (magneticField != null) {
sensorManager.registerListener(this, magneticField,
SensorManager.SENSOR_DELAY_NORMAL, SensorManager.SENSOR_DELAY_UI);
}
Now, implement the SensorEventListener in activity class and add these functions
@Override
public void onSensorChanged(SensorEvent sensorEvent) {
switch (sensorEvent.sensor.getType())
{
case Sensor.TYPE_MAGNETIC_FIELD:
mags = sensorEvent.values.clone();
break;
case Sensor.TYPE_ACCELEROMETER:
accels = sensorEvent.values.clone();
break;
}
if (mags != null && accels != null) {
Rot = new float[9];
I= new float[9];
SensorManager.getRotationMatrix(Rot, I, accels, mags);
// Correct if screen is in Landscape
float[] outR = new float[9];
SensorManager.remapCoordinateSystem(Rot, SensorManager.AXIS_X,SensorManager.AXIS_Z, outR);
SensorManager.getOrientation(outR, values);
// here we calculated the final yaw(azimuth), roll & pitch of the device.
// multiplied by a global standard value to get accurate results
// this is the yaw or the azimuth we need
yaw = values[0] * 57.2957795f;
pitch =values[1] * 57.2957795f;
roll = values[2] * 57.2957795f;
//retrigger the loop when things are repopulated
mags = null;
accels = null;
}
}
This code will help you to convert your desired LatLng into local coordinates to place model on it. It uses CoordinatesHelper class to do conversion. Make sure you call this code inside OnTapPlane Listener.
// instantiating our cordinates helper class with our current coordinate
CoordinatesHelper cartesianHelper=new CoordinatesHelper(currentLatLng);
cartesianHelper.setCenter_(currentLatLng);
// converting the LatLng coordinates of poi to local coordinates to get place in AR
Coordinate coordinate1 =
cartesianHelper.GetLocalCoordinates(new LatLng(
"Latitude", "Longitude"), yaw);
Below, we used onTapPlane to get information about our environment and set a node inside it. You can instantly place object without tapping the plane by using OnUpdateListener of ArFragment ArFrame. It is suggested to place first anchor on foot of user or beneath the camera for best results
arFragment.setOnTapArPlaneListener(new BaseArFragment.OnTapArPlaneListener() {
@Override
public void onTapPlane(HitResult hitResult, Plane plane, MotionEvent motionEvent) {
if(!poiPlaced) {
// calling it here as we want to calculate coordinates only when tapped
convertCoordinates("Latitude", "Longitude");
Anchor anchor= hitResult.createAnchor();
AnchorNode anchorNode = new AnchorNode(anchor);
// passing the coordinates of target from the list of coordinates,
// in your case you can set your own lat long and convert it into local coordinates,
// passing the anchorNode as the reference node to place other anchors in world.
// make sure you point the ar camera on your foot and then tap on ar shadow to place anchor
PlacePOIinRealWorld(coordinate1, anchorNode);
}
}
});
private void PlacePOIinRealWorld(CartesianCoordinate coordinate, AnchorNode reference) {
// prepare renderable model for POI
ModelRenderable.builder().
setSource(
ARActivity.this,
RenderableSource
.builder()
.setSource(ARActivity.this, Uri.parse(
poi_uri)
, RenderableSource.SourceType.GLTF2)
.setScale(.3f)
.build())
.setRegistryId(poi_uri)
.build()
.thenAccept(modelRenderable -> addPOIinScene( modelRenderable,reference, coordinate ))
.exceptionally(throwable -> {
Toast.makeText(ARActivity.this, "error:"+throwable.getCause(), Toast.LENGTH_SHORT).show();
return null;
});
poiPlaced=true;
binding.instrText.setVisibility(View.GONE);
}
private void addPOIinScene(ModelRenderable modelRenderable, AnchorNode reference, CartesianCoordinate targetCoordinate_) {
AnchorNode anchorNode1=new AnchorNode(null);
anchorNode1.setRenderable(modelRenderable);
arFragment.getArSceneView().getScene().addChild(anchorNode1);
CartesianCoordinate Singlecoordinate= targetCoordinate_;
//set the position of your POI model based on the coordinates calculated by
// the coordinate convertor
anchorNode1.setLocalPosition(new Vector3(
(float) (reference.getLocalPosition().x+ Singlecoordinate.getX()),
reference.getLocalPosition().y+.15f,
(float) (reference.getLocalPosition().z-Singlecoordinate.getY())
));
//set rotation if needed (optional)
anchorNode1.setLocalRotation(Quaternion.axisAngle(new Vector3(0f, -1f, 0f), 30f));
Toast.makeText(ARActivity.this, "POI added in scene.", Toast.LENGTH_SHORT).show();
poiPlaced= true;
}
Below, we used onTapPlane to get information about our environment and set a node inside it. You can instantly place object without tapping the plane by using OnUpdateListener of ArFragment ArFrame. It is suggested to place first anchor on foot of user or beneath the camera for best results
arFragment.setOnTapArPlaneListener(new BaseArFragment.OnTapArPlaneListener() {
@Override
public void onTapPlane(HitResult hitResult, Plane plane, MotionEvent motionEvent) {
if(!routePlaced) {
// calling it here as we want to calculate coordinates only when tapped
addDatainPOIList();
Anchor anchor= hitResult.createAnchor();
AnchorNode anchorNode = new AnchorNode(anchor);
DrawLinesBetweenPOIs(anchorNode, false);
for(int i=0; i<coordinateList.size(); i++) {
AnchorNode repNode= new AnchorNode(null);
repNode.setLocalPosition(
new Vector3((float) (anchorNode.getLocalPosition()
.x + coordinateList.get(i).getX()), anchorNode.getLocalPosition()
.y, (float) (anchorNode.getLocalPosition()
.z - coordinateList.get(i).getY())));
DrawLinesBetweenPOIs(repNode, true);
}
routePlaced=true;
binding.instrText.setVisibility(View.GONE);
}
}
});
private AnchorNode lastAnchorNode = new AnchorNode();
private void DrawLinesBetweenPOIs(AnchorNode anchorNode, boolean place_) {
if (lastAnchorNode != null) {
anchorNode.setParent(arFragment.getArSceneView().getScene());
Vector3 point1, point2;
point1 = lastAnchorNode.getWorldPosition();
point2 = anchorNode.getWorldPosition();
if(place_) {
final Vector3 difference = Vector3.subtract(point1, point2);
final Vector3 directionFromTopToBottom = difference.normalized();
final Quaternion rotationFromAToB =
Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
Texture.Sampler sampler = Texture.Sampler.builder()
.setMinFilter(Texture.Sampler.MinFilter.LINEAR_MIPMAP_LINEAR)
.setMagFilter(Texture.Sampler.MagFilter.LINEAR)
.build();
Texture.builder()
.setSource(() -> getApplicationContext().getAssets().open("arrow_texture.png"))
.setSampler(sampler)
.build().thenAccept(texture -> {
MaterialFactory.makeTransparentWithTexture(getApplicationContext(), texture) //new Color(0, 255, 244))
.thenAccept(
material -> {
ModelRenderable model = ShapeFactory.makeCube(
new Vector3(.3f, .006f, difference.length()),
Vector3.zero(), material);
AnchorNode node = new AnchorNode();
node.setParent(anchorNode);
node.setRenderable(model);
node.setWorldPosition(Vector3.add(point1, point2).scaled(.5f));
node.setWorldRotation(rotationFromAToB);
}
).exceptionally(new Function<Throwable, Void>() {
@Override
public Void apply(Throwable throwable) {
Toast.makeText(ARActivity.this, "Error: "+
throwable.getMessage().toString(), Toast.LENGTH_SHORT).show();
return null;
}
});
});
}
Log.d("position:",anchorNode.getLocalPosition().toString());
lastAnchorNode = anchorNode;
}
}
Thank you for viewing my repository, i hope it helped you achieve your desired results
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For any question or bug report, please send an email to bhaskar7005blur@gmail.com