GEO Example

[gelinger777]

Hi Everybody. I struggle to find a good replacement for https://github.com/kitcarson88/ionic-augmented-reality so that we could migrate our app from ionic to flutter. Do you have maybe an example of how to detect if in front of you is a GEO POI and show a pin properly on screen?

[jeromeDms]

Hi, did you finally found a flutter plugin that handles geo AR ? Thanks

[gelinger777]

@jeromeDms unfortunately no. The only one was there was from wikitude , but after they were aquired by qualcom they struggle to release new version for newest flutter since november ! And this is when its a commercial product which costs 2k yearly ! Thats very sad

[gelinger777]

@CariusLars could you maybe find time and help us in a right direction?

[LesGrob]

Hi. If I understand you correctly, you need to position the object with the geo-position relative to the user in AR. Here is my solution to calculate position vector for ARNode:

/// Returns position vector for node
///
/// Mark: [heading] is phone angel to True North in degrees
Vector3 positionVector(Position userPosition, double heading, LatLng nodeLocation) {
  final location1 = LatLng(userPosition.latitude, userPosition.longitude);

  final double bearing = MapUtil.sphereAngel(location1, nodeLocation);
  final double distance = MapUtil.sphereDistance(location1, nodeLocation);

  final double x = distance * cos(bearing);
  final double z = -distance * sin(bearing);

  final vector = Vector3(x, -1, z);
  vector.applyAxisAngle(Vector3(0, 1, 0), radians(heading));
  return vector;
}

double radians(double degrees) => degrees * pi / 180;

class MapUtil {
  /// Earth radius in meters
  static const double earthRadius = 6372795;

  /// Returns the angle from [location1] to [location2] in radians
  static double sphereAngel(LatLng location1, LatLng location2) {
    final double lat1 = radians(location1.latitude);
    final double lon1 = radians(location1.longitude);
    final double lat2 = radians(location2.latitude);
    final double lon2 = radians(location2.longitude);

    final delta = lon2 - lon1;

    final x = cos(lat2) * sin(delta);
    final y = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(delta);
    return atan2(x, y);
  }

  /// Returns distance between [location1] and [location2] on earth sphere in meters
  static double sphereDistance(LatLng location1, LatLng location2) {
    // radians
    final double lat1 = radians(location1.latitude);
    final double lon1 = radians(location1.longitude);
    final double lat2 = radians(location2.latitude);
    final double lon2 = radians(location2.longitude);

    // cosines and sines of widths and longitude difference
    final double cl1 = cos(lat1);
    final double cl2 = cos(lat2);
    final double sl1 = sin(lat1);
    final double sl2 = sin(lat2);
    final double delta = lon2 - lon1;
    final double cdelta = cos(delta);
    final double sdelta = sin(delta);

    // calculating the length of a great circle
    final double y =
        sqrt(pow(cl2 * sdelta, 2) + pow(cl1 * sl2 - sl1 * cl2 * cdelta, 2));
    final double x = sl1 * sl2 + cl1 * cl2 * cdelta;
    final double ad = atan2(y, x);
    return ad * earthRadius;
  }
}

And then use it like this:

ARNode(
  ...
  position: positionVector(position, heading, object),
  ...
)

[marcoabat]

Sadly this example doesn't produce any consistent results on my Nothing Phone (1). Can someone share their experience with this implementation or is there a different approach I could try?

[jeromeDms]

It seems there is a branch called 'gps-objects', but last commit has about 2 years, and it seems not fully implemented. Still looking for a flutter solution to achieve geo-based POIs to AR. Did you progress on this issue ? Thanks

[gelinger777]

I am tired to search.. I think I will have to go with commercial one.I am not naming it not to seems promoting them.

[justintoth]

@gelinger777 Please do share the name of the commercial product that you're using. I'm looking to do the same thing, where I want to plot for sale / for lease sign images in front of listed properties around the user, which requires anchoring the images to the lat/long coordinates of the properties.