Terrain exaggeration | ArcGIS Maps SDK for Qt

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Sample viewer app

Vertically exaggerate terrain in a scene.

Use case

Vertical exaggeration can be used to emphasize subtle changes in a surface. This can be useful in creating visualizations of terrain where the horizontal extent of the surface is significantly greater than the amount of vertical change in the surface. A fractional vertical exaggeration can be used to flatten surfaces or features that have extreme vertical variation.

How to use the sample

Use the slider to update terrain exaggeration.

How it works

Create an elevation source and add it to a new surface.
- An elevation source defines the terrain based on a digital elevation model (DEM) or digital terrain model (DTM).
Add the surface.
- The surface visualizes the elevation source.
Configure the surface’s elevation exaggeration using Surface::setElevationExaggeration.

Relevant API

Scene
Scene::baseSurface
Surface
Surface::elevationExaggeration

Sample Code

TerrainExaggeration.cpp

TerrainExaggeration.h

TerrainExaggeration.qml

main.cpp

// [WriteFile Name=TerrainExaggeration, Category=Scenes]
// [Legal]
// Copyright 2018 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

// sample headers
#include "TerrainExaggeration.h"

// ArcGIS Maps SDK headers
#include "ArcGISTiledElevationSource.h"
#include "Camera.h"
#include "ElevationSourceListModel.h"
#include "MapTypes.h"
#include "Point.h"
#include "Scene.h"
#include "SceneQuickView.h"
#include "SpatialReference.h"
#include "Surface.h"

// Qt headers
#include <QFuture>

using namespace Esri::ArcGISRuntime;

TerrainExaggeration::TerrainExaggeration(QQuickItem* parent /* = nullptr */):
  QQuickItem(parent)
{
}

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

void TerrainExaggeration::componentComplete()
{
  QQuickItem::componentComplete();

  // Create a scene and give it to the SceneView
  m_sceneView = findChild<SceneQuickView*>("sceneView");
  Scene* scene = new Scene(BasemapStyle::ArcGISTopographic, this);
  m_surface = new Surface(this);
  m_surface->elevationSources()->append(
        new ArcGISTiledElevationSource(
          QUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"),
          this));

  // Create the camera object at our initial viewpoint
  const Point initialPoint(-119.9616962169934, 46.7000413426849, 3183, SpatialReference(4326));
  const Camera initialViewpointCamera(initialPoint, 0, 7, 70, 0);

  // Set the initial ViewpointCamera for the scene
  m_sceneView->setViewpointCameraAsync(initialViewpointCamera);

  // Initialize the sceneview by applying the surface
  scene->setBaseSurface(m_surface);
  m_sceneView->setArcGISScene(scene);
}

void TerrainExaggeration::setElevationExaggeration(double factor)
{
  // If the surface exists, trigger a change in elevation exaggeration by [factor] amount
  if (m_surface)
    m_surface->setElevationExaggeration(factor);
}

// [WriteFile Name=TerrainExaggeration, Category=Scenes]
// [Legal]
// Copyright 2018 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]

#ifndef TERRAINEXAGGERATION_H
#define TERRAINEXAGGERATION_H

// Qt headers
#include <QQuickItem>

namespace Esri::ArcGISRuntime
{
class SceneQuickView;
class Surface;
}

class TerrainExaggeration : public QQuickItem
{
  Q_OBJECT

public:
  explicit TerrainExaggeration(QQuickItem* parent = nullptr);
  ~TerrainExaggeration() override = default;

  void componentComplete() override;
  static void init();
  Q_INVOKABLE void setElevationExaggeration(double factor);

private:
  Esri::ArcGISRuntime::SceneQuickView* m_sceneView = nullptr;
  Esri::ArcGISRuntime::Surface* m_surface = nullptr;
};

#endif // TERRAINEXAGGERATION_H

// [WriteFile Name=TerrainExaggeration, Category=Scenes]
// [Legal]
// Copyright 2018 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]

import QtQuick
import QtQuick.Controls
import Esri.Samples

TerrainExaggerationSample {
    id: terrainExaggerationSample
    clip: true
    width: 800
    height: 600

    SceneView {
        id: sceneView
        anchors.fill: parent
        objectName: "sceneView"

        Component.onCompleted: {
            // Set the focus on SceneView to initially enable keyboard navigation
            forceActiveFocus();
        }

        // Slider UI presentation at bottom
        Rectangle {
            anchors {
                horizontalCenter: parent.horizontalCenter
                bottom: sceneView.attributionTop
            }

            width: childrenRect.width
            height: childrenRect.height
            radius: 10
            opacity: 0.8

            // sliderCombo: A slider and text for its value
            Row {
                id: sliderCombo
                spacing: 5

                Slider {
                    id: slider
                    opacity: 0.7
                    anchors {
                        verticalCenter: parent.verticalCenter
                    }
                    // Slider controls degrees of rotation
                    from: 1
                    to: 10
                    onValueChanged: {
                        terrainExaggerationSample.setElevationExaggeration(slider.value);
                    }
                }

                Text {
                    anchors {
                        verticalCenter: parent.verticalCenter
                        margins: 5
                    }
                    horizontalAlignment: TextInput.AlignHCenter
                    font.pixelSize: 20
                    text: slider.value.toPrecision(2);
                }
            }
        }
    }
}

// [Legal]
// Copyright 2018 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]

// sample headers
#include "TerrainExaggeration.h"

// ArcGIS Maps SDK headers
#include "ArcGISRuntimeEnvironment.h"

// Qt headers
#include <QCommandLineParser>
#include <QDir>
#include <QGuiApplication>
#include <QQmlEngine>
#include <QQuickView>
#include <QSurfaceFormat>

// Platform specific headers
#ifdef Q_OS_WIN
#include <Windows.h>
#endif

#define STRINGIZE(x) #x
#define QUOTE(x) STRINGIZE(x)

int main(int argc, char *argv[])
{
  Esri::ArcGISRuntime::ArcGISRuntimeEnvironment::setUseLegacyAuthentication(false);
#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
  // Linux requires 3.2 OpenGL Context
  // in order to instance 3D symbols
  QSurfaceFormat fmt = QSurfaceFormat::defaultFormat();
  fmt.setVersion(3, 2);
  QSurfaceFormat::setDefaultFormat(fmt);
#endif

  QGuiApplication app(argc, argv);

  // Use of ArcGIS location services, such as basemap styles, geocoding, and routing services,
  // requires an access token. For more information see
  // https://links.esri.com/arcgis-runtime-security-auth.

  // The following methods grant an access token:

  // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
  // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
  // organization in ArcGIS Online or ArcGIS Enterprise.

  // 2. API key authentication: Get a long-lived access token that gives your application access to
  // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
  // Copy the API Key access token.

  const QString accessToken = QString("");

  if (accessToken.isEmpty())
  {
      qWarning() << "Use of ArcGIS location services, such as the basemap styles service, requires" <<
                    "you to authenticate with an ArcGIS account or set the API Key property.";
  }
  else
  {
      Esri::ArcGISRuntime::ArcGISRuntimeEnvironment::setApiKey(accessToken);
  }

  TerrainExaggeration::init();

  // Initialize application view
  QQuickView view;
  view.setResizeMode(QQuickView::SizeRootObjectToView);

  QString arcGISRuntimeImportPath = QUOTE(ARCGIS_RUNTIME_IMPORT_PATH);

#if defined(LINUX_PLATFORM_REPLACEMENT)
  // on some linux platforms the string 'linux' is replaced with 1
  // fix the replacement paths which were created
  QString replaceString = QUOTE(LINUX_PLATFORM_REPLACEMENT);
  arcGISRuntimeImportPath = arcGISRuntimeImportPath.replace(replaceString, "linux", Qt::CaseSensitive);
#endif

  // Add the import Path
  view.engine()->addImportPath(QDir(QCoreApplication::applicationDirPath()).filePath("qml"));
  // Add the Runtime and Extras path
  view.engine()->addImportPath(arcGISRuntimeImportPath);

  // Set the source
  view.setSource(QUrl("qrc:/Samples/Scenes/TerrainExaggeration/TerrainExaggeration.qml"));

  view.show();

  return app.exec();
}

Use case

How to use the sample

How it works

Relevant API

Tags

Sample Code