ARKit PickBuilding

[MephestoKhaan]

I am trying the simple task of picking buildings using the sample but using arkit. And it always select the same one (the centre one), even thought the LatLong that I am getting with the code is different.

Edit: Just to add more info, I just tried with something as simple as this:

void HighlightAtPosition (Vector3 tapPos)
        {
            var ray = lookingCamera.ScreenPointToRay (tapPos);

            RaycastHit hit;

            if (Physics.Raycast (ray, out hit))
            {
                var viewportPoint = lookingCamera.WorldToViewportPoint (hit.point);
                var latLongAlt = Api.Instance.CameraApi.ViewportToGeographicPoint (viewportPoint, lookingCamera);

                Api.Instance.BuildingsApi.GetBuildingAtLocation (latLongAlt, OnBuildingSelected);
                Api.Instance.BuildingsApi.HighlightBuildingAtLocation (latLongAlt, highlightMaterial, OnHighlightReceived);
            }
        }

        void OnBuildingSelected(bool success, Building b)
        {
            Debug.Log (b.BuildingId);
        }

I can confirm the latLongAlt has been different every time. But the b.BuildingId being printed has been the same always

[tim-jenks]

Could you please provide some example lat,lons that you are experiencing issues with?

Additionally, the buildingId returned would also help.

I'd recommend trying to debug visualise the Ray here: var ray = lookingCamera.ScreenPointToRay (tapPos); as this will help you to diagnose the issue.

[MephestoKhaan]

I did a small project that shows the problem, here is the link: https://wetransfer.com/downloads/f1aa7553eef76421521b7e96a8b3235520171018160315/96e21375156fc2b8923c53c0dad9ecc820171018160315/f3b710

An example of the results I am getting with this code:

        void HighlightAtPosition (Vector3 tapPos)
        {
            var ray = lookingCamera.ScreenPointToRay (tapPos);

            RaycastHit hit;

            if (Physics.Raycast (ray, out hit))
            {
                var viewportPoint = lookingCamera.WorldToViewportPoint (hit.point);
                var latLongAlt = Api.Instance.CameraApi.ViewportToGeographicPoint (viewportPoint, lookingCamera);

                Debug.Log(string.Format("Selecting building at: {0}  {1}",latLongAlt.GetLatitude(), latLongAlt.GetLongitude())); 
                Api.Instance.BuildingsApi.HighlightBuildingAtLocation (latLongAlt, highlightMaterial, OnHighlightReceived);
            }
        }

        void OnHighlightReceived (bool success, Highlight highlight)
        {
            Debug.Log(string.Format("Selected {0}",highlight.HighlightId));
            if (success)
            {
                StartCoroutine (ClearHighlight (highlight));
            }
        }

results:

Selecting building at: 37.8024105318418  -122.405865930829
Selected landmark_us_sf_coittower
Selected landmark_us_sf_coittower01
Selected landmark_us_sf_coittower-01
Selected landmark_us_sf_coittower02
Selected landmark_us_sf_coittower-02
Selected landmark_us_sf_coittower03
Selected landmark_us_sf_coittower-03
Selected landmark_us_sf_coittower04
Selected landmark_us_sf_coittower-04
Selected landmark_us_sf_coittower05
Selected landmark_us_sf_coittower-05
Selected landmark_us_sf_coittower06
Selected landmark_us_sf_coittower-06
Selected landmark_us_sf_coittower07
Selected landmark_us_sf_coittower-07
Selected landmark_us_sf_coittower08
Selected landmark_us_sf_coittower-08
Selected landmark_us_sf_coittower09
Selected landmark_us_sf_coittower-09

Selecting building at: 37.8024094102611  -122.405871354247
Selected landmark_us_sf_coittower
Selected landmark_us_sf_coittower01
Selected landmark_us_sf_coittower-01
Selected landmark_us_sf_coittower02
Selected landmark_us_sf_coittower-02
Selected landmark_us_sf_coittower03
Selected landmark_us_sf_coittower-03
Selected landmark_us_sf_coittower04
Selected landmark_us_sf_coittower-04
Selected landmark_us_sf_coittower05
Selected landmark_us_sf_coittower-05
Selected landmark_us_sf_coittower06
Selected landmark_us_sf_coittower-06
Selected landmark_us_sf_coittower07
Selected landmark_us_sf_coittower-07
Selected landmark_us_sf_coittower08
Selected landmark_us_sf_coittower-08
Selected landmark_us_sf_coittower09
Selected landmark_us_sf_coittower-09

[boblaublaw]

Quick nudge to check status here. (Luca and I are working together on this project.)

[tim-jenks]

Thanks, we'll investigate this for you as a priority!

[malcolm-brown]

Believe what you want to use in this case is the WorldToGeographicPoint method - this lets you convert a local Unity position into a LatLongAltitude for use with the Buildings API.

void HighlightAtPosition (Vector3 tapPos)
{
    var ray = lookingCamera.ScreenPointToRay (tapPos);

    RaycastHit hit;

    if (Physics.Raycast (ray, out hit))
    {
                var latLongAlt = Api.Instance.CameraApi.WorldToGeographicPoint(hit.point, lookingCamera);

        Debug.Log(string.Format("Selecting building at: {0}  {1}",latLongAlt.GetLatitude(), latLongAlt.GetLongitude())); 
        Api.Instance.BuildingsApi.HighlightBuildingAtLocation (latLongAlt, highlightMaterial, OnHighlightReceived);
    }
}

However, there's a bug where the WorldToGeographicPoint doesn't work if the root WrldMap object is being scaled, and in your project, it's being scaled by 1/1000. We'll get this fixed for the next release, but in the meantime you can work around this by making the following changes to Wrld/Scripts/ApiImplementation.cs:

1. Add field private Transform m_parentTransform;
2. Assign it in constructor via m_parentTransform = parentTransformForStreamedObjects;
3. In the WorldToGeographicPoint method (line 234) modify the code to be the following:

   internal LatLongAltitude WorldToGeographicPoint(Vector3 position, Camera camera)
   {
   if (m_coordinateSystem == CoordinateSystem.UnityWorld)
   {
       position = m_parentTransform.worldToLocalMatrix.MultiplyPoint(position);
       return m_frame.LocalSpaceToLatLongAltitude(position);
   }
   else
   {
       var ecefPosition = m_originECEF + position;
       return LatLongAltitude.FromECEF(ecefPosition);
   }
   }

This should transform the point into its correct space for conversion to a LatLong, and you should start seeing the correct buildings highlighting.

[MephestoKhaan]

Thanks I will try this asap. I suspected it was something related to the scale of the map indeed.

[MephestoKhaan]

Just as a note, I suspect the opposite (positioning elements in world space using latlong) will also be a problem if the map is scaled down. Is that something going in in the next update as well? Do you have an ETA?

[malcolm-brown]

You're right in that the other transforms will need similar modifications to get working too.

We're going to schedule to get the SDK properly handling scaling + transforms for a future release,

[MephestoKhaan]

Hi! I will need a similar fix for Geographic transforms, right now they appear all far away from where they should and I imagine it is the same problem. Tried modifying GeoToWorld but did not affected it.

[malcolm-brown]

Making the object with the GeographicTransform component a child of the WrldApp object that is being scaled should hopefully address this - its position should then be scaled along with the rest of the world.

We'll make a note to ensure GeographicTransforms also work correctly with a scaled map as well, reguardless of where they are in the scene, for the next release.

[yosun]

Just checking if this has been fixed?

[jonty-dawson]

Likely need to add API point to nominate a Unity camera as the instance for which projection-related API points will pull camera state from.

[tommymacdonald]

Tracked internally as MPLY-9058.

[ghost]

Believe this is now fixed - please re-open if not.