Valid earthpoint?

Rhino Developer
1

I put this test in my code:
ON_EarthAnchorPoint earthPoint = doc.Properties().EarthAnchorPoint();
if (earthPoint.EarthCoordinateSystem() != ON::EarthCoordinateSystem::Unset)
{
ON_3dVector northVec = earthPoint.ModelNorth();
double lat = earthPoint.Latitude();
// and other code like this
}

but it always evaluates as earthPoint.EarthCoordinateSystem() == ON::EarthCoordinateSystem::Unset even when I have set an EarthAnchorPoint in Rhino.

If I simply retrieve the values, I do get back the values I set, but I don’t want garbage values if the EarthAnchorPoint has not been set. Is there another way to tell if my values are valid?

2

Hi @mgraham,

The EarthAnchorPoint command does not set this value. So you’ll need to do so programatically.

CRhinoCommand::result CCommandTest::RunCommand(const CRhinoCommandContext& context)
{
  const double latitude_degrees = 47.620397;
  const double longitude_degrees = -122.349179;
  const double ground_elevation_feet = 207.0;
  const double observation_deck_height_feet = 520.0;

  ON_EarthAnchorPoint eap;
  eap.SetEarthLocation(
    ON::EarthCoordinateSystem::MeanSeaLevel,
    ON::LengthUnitSystem::Feet,
    latitude_degrees,
    longitude_degrees,
    ground_elevation_feet + observation_deck_height_feet
  );

  eap.m_name = L"Space Needle";
  eap.m_description = L"Space Needle, Seattle, Washington USA";
  eap.m_url = L"https://www.spaceneedle.com/";

  context.m_doc.Properties().SetEarthAnchorPoint(eap);

  return CRhinoCommand::success;
}

Use ON_EarthAnchorPoint::EarthLocationIsSet().

static bool PrintEarthAnchorPoint(CRhinoDoc& doc)
{
  const ON_EarthAnchorPoint& eap = doc.Properties().EarthAnchorPoint();
  bool rc = eap.EarthLocationIsSet();
  if (rc)
  {
    const ON_3dmUnitsAndTolerances& doc_units = doc.Properties().ModelUnitsAndTolerances();

    ON_3dmUnitsAndTolerances meters_units;
    meters_units.m_unit_system.SetUnitSystem(ON::LengthUnitSystem::Meters);

    ON_wString sLatitudeDMS, sLatitudeDeg;
    ON_wString sLongitudeDMS, sLongitudeDeg;
    ON_wString sElevation;

    double earth_latitude = eap.Latitude(0.0);
    double earth_longitude = eap.Longitude(0.0);
    double earth_elevation = eap.ElevationInMeters();

    RhinoFormatDegreesLatitude(earth_latitude, sLatitudeDMS, 0);
    RhinoFormatDegreesLongitude(earth_longitude, sLongitudeDMS, 0);

    RhinoFormatDegreesLatitude(earth_latitude, sLatitudeDeg, 1);
    RhinoFormatDegreesLongitude(earth_longitude, sLongitudeDeg, 1);
    RhinoFormatNumber(earth_elevation, meters_units, doc_units, sElevation, true);

    if (floor(earth_latitude) == earth_latitude)
      RhinoApp().Print(L"Latitude:  %s\n", sLatitudeDMS.Array());
    else
      RhinoApp().Print(L"Latitude:  %s (%s)\n", sLatitudeDMS.Array(), sLatitudeDeg.Array());

    if (floor(earth_longitude) == earth_longitude)
      RhinoApp().Print(L"Longitude: %s\n", sLongitudeDMS.Array());
    else
      RhinoApp().Print(L"Longitude: %s (%s)\n", sLongitudeDMS.Array(), sLongitudeDeg.Array());

    RhinoApp().Print(L"Elevation: %s\n", sElevation.Array());
  }

  return rc;
}

space-needle.zip (1.2 MB)

– Dale

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