Distance measurement analysis

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QML

C++

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Sample viewer app

Measure distances between two points in 3D.

screenshot

Use case

The distance measurement analysis allows you to add to your app the same interactive measuring experience found in ArcGIS Pro, City Engine, and the ArcGIS API for JavaScript. You can set the unit system of measurement (metric or imperial). The units automatically switch to one appropriate for the current scale.

How to use the sample

Choose a unit system for the measurement. Click any location in the scene to start measuring. Move the mouse to an end location, and click to complete the measurement. Click a new location to clear and start a new measurement.

How it works

Create an AnalysisOverlay object and add it to the analysis overlay collection of the SceneView object.
Specify the start location and end location to create a LocationDistanceMeasurement object. Initially, the start and end locations can be the same point.
Add the location distance measurement analysis to the analysis overlay.
The measurementChanged signal will trigger if the distances change. You can get the new values for the directDistance, horizontalDistance, and verticalDistance from the MeasurementChanged object returned by the signal.

Relevant API

AnalysisOverlay
LocationDistanceMeasurement
MeasurementChanged

Additional information

The LocationDistanceMeasurement analysis only performs planar distance calculations. This may not be appropriate for large distances where the Earth's curvature must be considered.

Sample Code

DistanceMeasurementAnalysis.cppDistanceMeasurementAnalysis.cppDistanceMeasurementAnalysis.hDistanceMeasurementAnalysis.qml
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// [WriteFile Name=DistanceMeasurementAnalysis, Category=Analysis]
// [Legal]
// Copyright 2022 Esri.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]

#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD

#include "DistanceMeasurementAnalysis.h"

#include "AnalysisListModel.h"
#include "AnalysisOverlay.h"
#include "AnalysisOverlayListModel.h"
#include "ArcGISSceneLayer.h"
#include "ArcGISTiledElevationSource.h"
#include "Camera.h"
#include "CoreTypes.h"
#include "Distance.h"
#include "ElevationSourceListModel.h"
#include "LayerListModel.h"
#include "LinearUnit.h"
#include "LocationDistanceMeasurement.h"
#include "MapTypes.h"
#include "Point.h"
#include "Scene.h"
#include "SceneQuickView.h"
#include "SpatialReference.h"
#include "Surface.h"
#include "TaskWatcher.h"
#include "Viewpoint.h"

#include <QUuid>

using namespace Esri::ArcGISRuntime;

DistanceMeasurementAnalysis::DistanceMeasurementAnalysis(QObject* parent /* = nullptr */):
  QObject(parent),
  m_scene(new Scene(BasemapStyle::ArcGISTopographic, this))
{
  // create a new elevation source from Terrain3D REST service
  ArcGISTiledElevationSource* elevationSource = new ArcGISTiledElevationSource(
        QUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"), this);

  // add the elevation source to the scene to display elevation
  m_scene->baseSurface()->elevationSources()->append(elevationSource);

  // Add a Scene Layer
  ArcGISSceneLayer* sceneLayer = new ArcGISSceneLayer(QUrl("https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Brest/SceneServer/layers/0"), this);
  sceneLayer->setAltitudeOffset(1); // The elevation source is a very fine resolution so we raise the scene layer slightly so it does not clip the surface

  m_scene->operationalLayers()->append(sceneLayer);
}

DistanceMeasurementAnalysis::~DistanceMeasurementAnalysis() = default;

void DistanceMeasurementAnalysis::init()
{
  // Register classes for QML
  qmlRegisterType<SceneQuickView>("Esri.Samples", 1, 0, "SceneView");
  qmlRegisterType<DistanceMeasurementAnalysis>("Esri.Samples", 1, 0, "DistanceMeasurementAnalysisSample");
}

SceneQuickView* DistanceMeasurementAnalysis::sceneView() const
{
  return m_sceneView;
}

// Set the view (created in QML)
void DistanceMeasurementAnalysis::setSceneView(SceneQuickView* sceneView)
{
  if (!sceneView || sceneView == m_sceneView)
    return;

  m_sceneView = sceneView;
  m_sceneView->setArcGISScene(m_scene);
  emit sceneViewChanged();

  // Add Analysis Overlay
  AnalysisOverlay* analysisOverlay = new AnalysisOverlay(this);
  m_sceneView->analysisOverlays()->append(analysisOverlay);

  // Create and add the LocationDistanceMeasurement
  const Point startLocation(-4.494677, 48.384472, 24.772694, SpatialReference::wgs84());
  const Point endLocation(-4.495646, 48.384377, 58.501115, SpatialReference::wgs84());
  m_distanceAnalysis = new LocationDistanceMeasurement(startLocation, endLocation, this);
  m_distanceAnalysis->setUnitSystem(UnitSystem::Metric);
  analysisOverlay->analyses()->append(m_distanceAnalysis);

  // Set initial viewpoint
  constexpr double distance = 400.0;
  constexpr double pitch = 45.0;
  constexpr double heading = 0.0;
  constexpr double roll = 0.0;
  const Camera initCamera(startLocation, distance, heading, pitch, roll);
  const Viewpoint initViewpoint(startLocation, distance, initCamera);
  m_scene->setInitialViewpoint(initViewpoint);

  connectSignals();
}

void DistanceMeasurementAnalysis::connectSignals()
{
  // connect to signal to obtain updated distances
  connect(m_distanceAnalysis, &LocationDistanceMeasurement::measurementChanged, this, [this](const Distance& directDistance,
                                                                                             const Distance& horizontalDistance,
                                                                                             const Distance& verticalDistance)
  {
    m_directDistance = QString::number(directDistance.value(), 'f', 2) + QString(" %1").arg(directDistance.unit().abbreviation());
    m_horizontalDistance = QString::number(horizontalDistance.value(), 'f', 2) + QString(" %1").arg(horizontalDistance.unit().abbreviation());
    m_verticalDistance = QString::number(verticalDistance.value(), 'f', 2) + QString(" %1").arg(verticalDistance.unit().abbreviation());
    emit directDistanceChanged();
    emit horizontalDistanceChanged();
    emit verticalDistanceChanged();
  });

  // connect to mouse signals to update the analysis

  // When the mouse is pressed and held, start updating the distance analysis end point
  connect(m_sceneView, &SceneQuickView::mousePressedAndHeld, this, [this](QMouseEvent& mouseEvent)
  {
    m_isPressAndHold = true;
    m_sceneView->screenToLocation(mouseEvent.position().x(), mouseEvent.position().y());
  });

  // When the mouse is released...
  connect(m_sceneView, &SceneQuickView::mouseReleased, this, [this](QMouseEvent& mouseEvent)
  {
    // Check if the mouse was released from a pan gesture
    if (m_isNavigating)
    {
      m_isNavigating = false;
      return;
    }

    // Ignore if Right click
    if (mouseEvent.button() == Qt::RightButton)
      return;

    // If pressing and holding, do nothing
    if (m_isPressAndHold)
      m_isPressAndHold = false;
    // Else get the location from the screen coordinates
    else
      m_sceneView->screenToLocation(mouseEvent.position().x(), mouseEvent.position().y());
  });

  // Update the distance analysis when the mouse moves if it is a press and hold movement
  connect(m_sceneView, &SceneQuickView::mouseMoved, this, [this](QMouseEvent& mouseEvent)
  {
    if (m_isPressAndHold)
      m_sceneView->screenToLocation(mouseEvent.position().x(), mouseEvent.position().y());
  });

  // Set a flag when mousePressed signal emits
  connect(m_sceneView, &SceneQuickView::mousePressed, this, [this]
  {
    m_isNavigating = false;
  });

  // When screenToLocation completes...
  connect(m_sceneView, &SceneQuickView::screenToLocationCompleted, this, [this](const QUuid&, const Point& pt)
  {
    // If it was from a press and hold, update the end location
    if (m_isPressAndHold)
      m_distanceAnalysis->setEndLocation(pt);
    // Else if it was a normal mouse click (press and release), update the start location
    else
      m_distanceAnalysis->setStartLocation(pt);
  });

  // Set a flag when viewpointChanged signal emits
  connect(m_sceneView, &SceneQuickView::viewpointChanged, this, [this]
  {
    m_isNavigating = true;
  });
}

void DistanceMeasurementAnalysis::setUnits(const QString& unitName)
{
  if (!m_distanceAnalysis)
    return;

  if (unitName == "Metric")
    m_distanceAnalysis->setUnitSystem(UnitSystem::Metric);
  else
    m_distanceAnalysis->setUnitSystem(UnitSystem::Imperial);
}

QString DistanceMeasurementAnalysis::directDistance() const
{
  return m_directDistance;
}

QString DistanceMeasurementAnalysis::horizontalDistance() const
{
  return m_horizontalDistance;
}

QString DistanceMeasurementAnalysis::verticalDistance() const
{
  return m_verticalDistance;
}

ArcGIS Maps SDK for QtC++ samples

Distance measurement analysis

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ArcGIS Maps SDK for QtC++ samples

Distance measurement analysis

Use case

How to use the sample

How it works

Relevant API

Additional information

Tags

Sample Code

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