Add QgsMapLayerElevationProperties subclass for raster layers

Allows elevation properties to be set for raster layers, including:

- whether raster values represent heights
- scale
- offset

These properties can be set through the new "Elevation" tab in
the raster layer properties dialog

python/core/auto_generated/qgsmaplayerelevationproperties.sip.in

@@ -25,12 +25,17 @@ how an individual :py:class:`QgsMapLayer` behaves with relation to z values or e
 %TypeHeaderCode
 #include "qgsmaplayerelevationproperties.h"
 #include "qgspointcloudlayerelevationproperties.h"
+#include "qgsrasterlayerelevationproperties.h"
 %End
 %ConvertToSubClassCode
     if ( qobject_cast<QgsPointCloudLayerElevationProperties *>( sipCpp ) )
     {
       sipType = sipType_QgsPointCloudLayerElevationProperties;
     }
+    else if ( qobject_cast<QgsRasterLayerElevationProperties *>( sipCpp ) )
+    {
+      sipType = sipType_QgsRasterLayerElevationProperties;
+    }
     else
     {
       sipType = 0;

python/core/auto_generated/raster/qgsrasterlayer.sip.in

@@ -421,6 +421,8 @@ to be drawn outside the data extent.
 
     virtual QgsMapLayerTemporalProperties *temporalProperties();
 
+    virtual QgsMapLayerElevationProperties *elevationProperties();
+
 
   public slots:
     void showStatusMessage( const QString &message );

python/core/auto_generated/raster/qgsrasterlayerelevationproperties.sip.in

@@ -0,0 +1,112 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/raster/qgsrasterlayerelevationproperties.h                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsRasterLayerElevationProperties : QgsMapLayerElevationProperties
+{
+%Docstring(signature="appended")
+Raster layer specific subclass of :py:class:`QgsMapLayerElevationProperties`.
+
+.. versionadded:: 3.26
+%End
+
+%TypeHeaderCode
+#include "qgsrasterlayerelevationproperties.h"
+%End
+  public:
+
+    QgsRasterLayerElevationProperties( QObject *parent /TransferThis/ );
+%Docstring
+Constructor for QgsRasterLayerElevationProperties, with the specified ``parent`` object.
+%End
+
+    virtual bool hasElevation() const;
+
+    virtual QDomElement writeXml( QDomElement &element, QDomDocument &doc, const QgsReadWriteContext &context );
+
+    virtual bool readXml( const QDomElement &element, const QgsReadWriteContext &context );
+
+    virtual bool isVisibleInZRange( const QgsDoubleRange &range ) const;
+
+    virtual QgsDoubleRange calculateZRange( QgsMapLayer *layer ) const;
+
+
+    bool isEnabled() const;
+%Docstring
+Returns ``True`` if the elevation properties are enabled, i.e. the raster layer values represent an elevation surface.
+
+.. seealso:: :py:func:`setEnabled`
+%End
+
+    void setEnabled( bool enabled );
+%Docstring
+Sets whether the elevation properties are enabled, i.e. the raster layer values represent an elevation surface.
+
+.. seealso:: :py:func:`isEnabled`
+%End
+
+    double zOffset() const;
+%Docstring
+Returns the z offset, which is a fixed offset amount which should be added to z values from
+the layer.
+
+.. note::
+
+   Any scaling specified via :py:func:`~QgsRasterLayerElevationProperties.zScale` is applied before any offset value specified via :py:func:`~QgsRasterLayerElevationProperties.zOffset`
+
+.. seealso:: :py:func:`setZOffset`
+%End
+
+    void setZOffset( double offset );
+%Docstring
+Sets the z ``offset``, which is a fixed offset amount which will be added to z values from
+the layer.
+
+.. note::
+
+   Any scaling specified via :py:func:`~QgsRasterLayerElevationProperties.zScale` is applied before any offset value specified via :py:func:`~QgsRasterLayerElevationProperties.zOffset`
+
+.. seealso:: :py:func:`zOffset`
+%End
+
+    double zScale() const;
+%Docstring
+Returns the z scale, which is a scaling factor which should be applied to z values from
+the layer.
+
+.. note::
+
+   Any scaling specified via :py:func:`~QgsRasterLayerElevationProperties.zScale` is applied before any offset value specified via :py:func:`~QgsRasterLayerElevationProperties.zOffset`
+
+.. seealso:: :py:func:`setZScale`
+%End
+
+    void setZScale( double scale );
+%Docstring
+Sets the z ``scale``, which is a scaling factor which will be applied to z values from
+the layer.
+
+.. note::
+
+   Any scaling specified via :py:func:`~QgsRasterLayerElevationProperties.zScale` is applied before any offset value specified via :py:func:`~QgsRasterLayerElevationProperties.zOffset`
+
+.. seealso:: :py:func:`zScale`
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/raster/qgsrasterlayerelevationproperties.h                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/core_auto.sip

@@ -577,6 +577,7 @@
 %Include auto_generated/raster/qgsrasterinterface.sip
 %Include auto_generated/raster/qgsrasteriterator.sip
 %Include auto_generated/raster/qgsrasterlayer.sip
+%Include auto_generated/raster/qgsrasterlayerelevationproperties.sip
 %Include auto_generated/raster/qgsrasterlayertemporalproperties.sip
 %Include auto_generated/raster/qgsrasterminmaxorigin.sip
 %Include auto_generated/raster/qgsrasternuller.sip

src/app/CMakeLists.txt

@@ -130,6 +130,8 @@ set(QGIS_APP_SRCS
   pointcloud/qgspointcloudlayerproperties.cpp
   pointcloud/qgspointcloudlayerstylewidget.cpp
 
+  raster/qgsrasterelevationpropertieswidget.cpp
+
   vectortile/qgsvectortilelayerproperties.cpp
 
   vertextool/qgslockedfeature.cpp

src/app/qgisapp.cpp

@@ -117,6 +117,8 @@
 #include "options/qgsgpsdeviceoptions.h"
 #include "options/qgscustomprojectionoptions.h"
 
+#include "raster/qgsrasterelevationpropertieswidget.h"
+
 #ifdef HAVE_3D
 #include "qgs3d.h"
 #include "qgs3danimationsettings.h"
@@ -1478,6 +1480,7 @@ QgisApp::QgisApp( QSplashScreen *splash, bool restorePlugins, bool skipBadLayers
   registerMapLayerPropertiesFactory( new QgsPointCloudLayer3DRendererWidgetFactory( this ) );
 #endif
   registerMapLayerPropertiesFactory( new QgsPointCloudElevationPropertiesWidgetFactory( this ) );
+  registerMapLayerPropertiesFactory( new QgsRasterElevationPropertiesWidgetFactory( this ) );
   registerMapLayerPropertiesFactory( new QgsAnnotationItemPropertiesWidgetFactory( this ) );
   registerMapLayerPropertiesFactory( new QgsLayerTreeGroupPropertiesWidgetFactory( this ) );
 

src/app/raster/qgsrasterelevationpropertieswidget.cpp

@@ -0,0 +1,107 @@
+/***************************************************************************
+    qgsrasterelevationpropertieswidget.cpp
+    ---------------------
+    begin                : February 2022
+    copyright            : (C) 2022 by Nyall Dawson
+    email                : nyall dot dawson at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsrasterelevationpropertieswidget.h"
+#include "qgsstyle.h"
+#include "qgsapplication.h"
+#include "qgsmaplayer.h"
+#include "qgsrasterlayer.h"
+#include "qgsrasterlayerelevationproperties.h"
+
+QgsRasterElevationPropertiesWidget::QgsRasterElevationPropertiesWidget( QgsRasterLayer *layer, QgsMapCanvas *canvas, QWidget *parent )
+  : QgsMapLayerConfigWidget( layer, canvas, parent )
+{
+  setupUi( this );
+
+  mOffsetZSpinBox->setClearValue( 0 );
+  mScaleZSpinBox->setClearValue( 1 );
+  mElevationGroupBox->setChecked( false );
+
+  syncToLayer( layer );
+
+  connect( mOffsetZSpinBox, qOverload<double >( &QDoubleSpinBox::valueChanged ), this, &QgsRasterElevationPropertiesWidget::onChanged );
+  connect( mScaleZSpinBox, qOverload<double >( &QDoubleSpinBox::valueChanged ), this, &QgsRasterElevationPropertiesWidget::onChanged );
+  connect( mElevationGroupBox, &QGroupBox::toggled, this, &QgsRasterElevationPropertiesWidget::onChanged );
+}
+
+void QgsRasterElevationPropertiesWidget::syncToLayer( QgsMapLayer *layer )
+{
+  mLayer = qobject_cast< QgsRasterLayer * >( layer );
+  if ( !mLayer )
+    return;
+
+  mBlockUpdates = true;
+  const QgsRasterLayerElevationProperties *props = qgis::down_cast< const QgsRasterLayerElevationProperties * >( mLayer->elevationProperties() );
+  mElevationGroupBox->setChecked( props->isEnabled() );
+  mOffsetZSpinBox->setValue( props->zOffset() );
+  mScaleZSpinBox->setValue( props->zScale() );
+  mBlockUpdates = false;
+}
+
+void QgsRasterElevationPropertiesWidget::apply()
+{
+  if ( !mLayer )
+    return;
+
+  QgsRasterLayerElevationProperties *props = qgis::down_cast< QgsRasterLayerElevationProperties * >( mLayer->elevationProperties() );
+  props->setEnabled( mElevationGroupBox->isChecked() );
+  props->setZOffset( mOffsetZSpinBox->value() );
+  props->setZScale( mScaleZSpinBox->value() );
+  mLayer->trigger3DUpdate();
+}
+
+void QgsRasterElevationPropertiesWidget::onChanged()
+{
+  if ( !mBlockUpdates )
+    emit widgetChanged();
+}
+
+
+//
+// QgsRasterElevationPropertiesWidgetFactory
+//
+
+QgsRasterElevationPropertiesWidgetFactory::QgsRasterElevationPropertiesWidgetFactory( QObject *parent )
+  : QObject( parent )
+{
+  setIcon( QgsApplication::getThemeIcon( QStringLiteral( "propertyicons/elevationscale.svg" ) ) );
+  setTitle( tr( "Elevation" ) );
+}
+
+QgsMapLayerConfigWidget *QgsRasterElevationPropertiesWidgetFactory::createWidget( QgsMapLayer *layer, QgsMapCanvas *canvas, bool, QWidget *parent ) const
+{
+  return new QgsRasterElevationPropertiesWidget( qobject_cast< QgsRasterLayer * >( layer ), canvas, parent );
+}
+
+bool QgsRasterElevationPropertiesWidgetFactory::supportLayerPropertiesDialog() const
+{
+  return true;
+}
+
+bool QgsRasterElevationPropertiesWidgetFactory::supportsStyleDock() const
+{
+  return true;
+}
+
+bool QgsRasterElevationPropertiesWidgetFactory::supportsLayer( QgsMapLayer *layer ) const
+{
+  return layer->type() == QgsMapLayerType::RasterLayer;
+}
+
+QString QgsRasterElevationPropertiesWidgetFactory::layerPropertiesPagePositionHint() const
+{
+  return QStringLiteral( "mOptsPage_Metadata" );
+}
+

src/app/raster/qgsrasterelevationpropertieswidget.h

@@ -0,0 +1,65 @@
+/***************************************************************************
+    qgsrasterelevationpropertieswidget.h
+    ---------------------
+    begin                : February 2022
+    copyright            : (C) 2022 by Nyall Dawson
+    email                : nyall dot dawson at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSRASTERELEVATIONPROPERTIESWIDGET_H
+#define QGSRASTERELEVATIONPROPERTIESWIDGET_H
+
+#include "qgsmaplayerconfigwidget.h"
+#include "qgsmaplayerconfigwidgetfactory.h"
+
+#include "ui_qgsrasterelevationpropertieswidgetbase.h"
+
+class QgsRasterLayer;
+
+class QgsRasterElevationPropertiesWidget : public QgsMapLayerConfigWidget, private Ui::QgsRasterElevationPropertiesWidgetBase
+{
+    Q_OBJECT
+  public:
+
+    QgsRasterElevationPropertiesWidget( QgsRasterLayer *layer, QgsMapCanvas *canvas, QWidget *parent );
+
+    void syncToLayer( QgsMapLayer *layer ) override;
+
+  public slots:
+    void apply() override;
+
+  private slots:
+
+    void onChanged();
+
+  private:
+
+    QgsRasterLayer *mLayer = nullptr;
+    bool mBlockUpdates = false;
+
+};
+
+
+class QgsRasterElevationPropertiesWidgetFactory : public QObject, public QgsMapLayerConfigWidgetFactory
+{
+    Q_OBJECT
+  public:
+    explicit QgsRasterElevationPropertiesWidgetFactory( QObject *parent = nullptr );
+
+    QgsMapLayerConfigWidget *createWidget( QgsMapLayer *layer, QgsMapCanvas *canvas, bool dockWidget, QWidget *parent ) const override;
+    bool supportLayerPropertiesDialog() const override;
+    bool supportsStyleDock() const override;
+    bool supportsLayer( QgsMapLayer *layer ) const override;
+    QString layerPropertiesPagePositionHint() const override;
+};
+
+
+
+#endif // QGSRASTERELEVATIONPROPERTIESWIDGET_H

src/core/CMakeLists.txt

@@ -657,6 +657,7 @@ set(QGIS_CORE_SRCS
   raster/qgsrasterinterface.cpp
   raster/qgsrasteriterator.cpp
   raster/qgsrasterlayer.cpp
+  raster/qgsrasterlayerelevationproperties.cpp
   raster/qgsrasterlayerrenderer.cpp
   raster/qgsrasterlayertemporalproperties.cpp
   raster/qgsrasterminmaxorigin.cpp
@@ -1648,6 +1649,7 @@ set(QGIS_CORE_HDRS
   raster/qgsrasterinterface.h
   raster/qgsrasteriterator.h
   raster/qgsrasterlayer.h
+  raster/qgsrasterlayerelevationproperties.h
   raster/qgsrasterlayerrenderer.h
   raster/qgsrasterlayertemporalproperties.h
   raster/qgsrasterminmaxorigin.h

src/core/qgsmaplayerelevationproperties.h

@@ -41,6 +41,7 @@ class CORE_EXPORT QgsMapLayerElevationProperties : public QObject
 {
 #ifdef SIP_RUN
 #include "qgspointcloudlayerelevationproperties.h"
+#include "qgsrasterlayerelevationproperties.h"
 #endif
 
     Q_OBJECT
@@ -51,6 +52,10 @@ class CORE_EXPORT QgsMapLayerElevationProperties : public QObject
     {
       sipType = sipType_QgsPointCloudLayerElevationProperties;
     }
+    else if ( qobject_cast<QgsRasterLayerElevationProperties *>( sipCpp ) )
+    {
+      sipType = sipType_QgsRasterLayerElevationProperties;
+    }
     else
     {
       sipType = 0;

src/core/raster/qgsrasterlayer.cpp

@@ -59,6 +59,7 @@ email                : tim at linfiniti.com
 #include "qgsruntimeprofiler.h"
 #include "qgsmaplayerfactory.h"
 #include "qgsrasterpipe.h"
+#include "qgsrasterlayerelevationproperties.h"
 
 #include <cmath>
 #include <cstdio>
@@ -107,8 +108,8 @@ QgsRasterLayer::QgsRasterLayer()
   , QSTRING_NOT_SET( QStringLiteral( "Not Set" ) )
   , TRSTRING_NOT_SET( tr( "Not Set" ) )
   , mTemporalProperties( new QgsRasterLayerTemporalProperties( this ) )
+  , mElevationProperties( new QgsRasterLayerElevationProperties( this ) )
   , mPipe( std::make_unique< QgsRasterPipe >() )
-
 {
   init();
   setValid( false );
@@ -123,6 +124,7 @@ QgsRasterLayer::QgsRasterLayer( const QString &uri,
   , QSTRING_NOT_SET( QStringLiteral( "Not Set" ) )
   , TRSTRING_NOT_SET( tr( "Not Set" ) )
   , mTemporalProperties( new QgsRasterLayerTemporalProperties( this ) )
+  , mElevationProperties( new QgsRasterLayerElevationProperties( this ) )
   , mPipe( std::make_unique< QgsRasterPipe >() )
 {
   mShouldValidateCrs = !options.skipCrsValidation;
@@ -1070,6 +1072,11 @@ QgsMapLayerTemporalProperties *QgsRasterLayer::temporalProperties()
   return mTemporalProperties;
 }
 
+QgsMapLayerElevationProperties *QgsRasterLayer::elevationProperties()
+{
+  return mElevationProperties;
+}
+
 void QgsRasterLayer::setContrastEnhancement( QgsContrastEnhancement::ContrastEnhancementAlgorithm algorithm, QgsRasterMinMaxOrigin::Limits limits, const QgsRectangle &extent, int sampleSize, bool generateLookupTableFlag )
 {
   setContrastEnhancement( algorithm,

src/core/raster/qgsrasterlayer.h

@@ -47,6 +47,7 @@ class QgsRasterPipe;
 class QgsRasterResampleFilter;
 class QgsBrightnessContrastFilter;
 class QgsHueSaturationFilter;
+class QgsRasterLayerElevationProperties;
 
 class QImage;
 class QPixmap;
@@ -467,6 +468,7 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     bool ignoreExtents() const;
 
     QgsMapLayerTemporalProperties *temporalProperties() override;
+    QgsMapLayerElevationProperties *elevationProperties() override;
 
   public slots:
     void showStatusMessage( const QString &message );
@@ -552,6 +554,8 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     //! Pointer to temporal properties
     QgsRasterLayerTemporalProperties *mTemporalProperties = nullptr;
 
+    QgsRasterLayerElevationProperties *mElevationProperties = nullptr;
+
     //! [ data provider interface ] Timestamp, the last modified time of the data source when the layer was created
     QDateTime mLastModified;
 

src/core/raster/qgsrasterlayerelevationproperties.cpp

@@ -0,0 +1,60 @@
+/***************************************************************************
+                         qgsrasterlayerelevationproperties.cpp
+                         ---------------
+    begin                : February 2022
+    copyright            : (C) 2022 by Nyall Dawson
+    email                : nyall dot dawson dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsrasterlayerelevationproperties.h"
+#include "qgsrasterlayer.h"
+
+QgsRasterLayerElevationProperties::QgsRasterLayerElevationProperties( QObject *parent )
+  : QgsMapLayerElevationProperties( parent )
+{
+}
+
+bool QgsRasterLayerElevationProperties::hasElevation() const
+{
+  return mEnabled;
+}
+
+QDomElement QgsRasterLayerElevationProperties::writeXml( QDomElement &parentElement, QDomDocument &document, const QgsReadWriteContext & )
+{
+  QDomElement element = document.createElement( QStringLiteral( "elevation" ) );
+  element.setAttribute( QStringLiteral( "enabled" ), mEnabled ? QStringLiteral( "1" ) : QStringLiteral( "0" ) );
+  element.setAttribute( QStringLiteral( "zoffset" ), qgsDoubleToString( mZOffset ) );
+  element.setAttribute( QStringLiteral( "zscale" ), qgsDoubleToString( mZScale ) );
+  parentElement.appendChild( element );
+  return element;
+}
+
+bool QgsRasterLayerElevationProperties::readXml( const QDomElement &element, const QgsReadWriteContext & )
+{
+  const QDomElement elevationElement = element.firstChildElement( QStringLiteral( "elevation" ) ).toElement();
+  mEnabled = elevationElement.attribute( QStringLiteral( "enabled" ), QStringLiteral( "0" ) ).toInt();
+  mZOffset = elevationElement.attribute( QStringLiteral( "zoffset" ), QStringLiteral( "0" ) ).toDouble();
+  mZScale = elevationElement.attribute( QStringLiteral( "zscale" ), QStringLiteral( "1" ) ).toDouble();
+  return true;
+}
+
+bool QgsRasterLayerElevationProperties::isVisibleInZRange( const QgsDoubleRange & ) const
+{
+  // TODO -- test actual raster z range
+  return true;
+}
+
+QgsDoubleRange QgsRasterLayerElevationProperties::calculateZRange( QgsMapLayer * ) const
+{
+  // TODO -- determine actual z range from raster statistics
+  return QgsDoubleRange();
+}

src/core/raster/qgsrasterlayerelevationproperties.h

@@ -0,0 +1,112 @@
+/***************************************************************************
+                         qgsrasterlayerelevationproperties.h
+                         ---------------
+    begin                : February 2022
+    copyright            : (C) 2022 by Nyall Dawson
+    email                : nyall dot dawson dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+
+#ifndef QGSRASTERLAYERELEVATIONPROPERTIES_H
+#define QGSRASTERLAYERELEVATIONPROPERTIES_H
+
+#include "qgis_core.h"
+#include "qgis_sip.h"
+#include "qgsmaplayerelevationproperties.h"
+
+/**
+ * \class QgsRasterLayerElevationProperties
+ * \ingroup core
+ * \brief Raster layer specific subclass of QgsMapLayerElevationProperties.
+ *
+ * \since QGIS 3.26
+ */
+class CORE_EXPORT QgsRasterLayerElevationProperties : public QgsMapLayerElevationProperties
+{
+
+    Q_OBJECT
+
+  public:
+
+    /**
+     * Constructor for QgsRasterLayerElevationProperties, with the specified \a parent object.
+     */
+    QgsRasterLayerElevationProperties( QObject *parent SIP_TRANSFERTHIS );
+
+    bool hasElevation() const override;
+    QDomElement writeXml( QDomElement &element, QDomDocument &doc, const QgsReadWriteContext &context ) override;
+    bool readXml( const QDomElement &element, const QgsReadWriteContext &context ) override;
+    bool isVisibleInZRange( const QgsDoubleRange &range ) const override;
+    QgsDoubleRange calculateZRange( QgsMapLayer *layer ) const override;
+
+    /**
+     * Returns TRUE if the elevation properties are enabled, i.e. the raster layer values represent an elevation surface.
+     *
+     * \see setEnabled()
+     */
+    bool isEnabled() const { return mEnabled; }
+
+    /**
+     * Sets whether the elevation properties are enabled, i.e. the raster layer values represent an elevation surface.
+     *
+     * \see isEnabled()
+     */
+    void setEnabled( bool enabled ) { mEnabled = enabled; }
+
+    /**
+     * Returns the z offset, which is a fixed offset amount which should be added to z values from
+     * the layer.
+     *
+     * \note Any scaling specified via zScale() is applied before any offset value specified via zOffset()
+     *
+     * \see setZOffset()
+     */
+    double zOffset() const { return mZOffset; }
+
+    /**
+     * Sets the z \a offset, which is a fixed offset amount which will be added to z values from
+     * the layer.
+     *
+     * \note Any scaling specified via zScale() is applied before any offset value specified via zOffset()
+     *
+     * \see zOffset()
+     */
+    void setZOffset( double offset ) { mZOffset = offset; }
+
+    /**
+     * Returns the z scale, which is a scaling factor which should be applied to z values from
+     * the layer.
+     *
+     * \note Any scaling specified via zScale() is applied before any offset value specified via zOffset()
+     *
+     * \see setZScale()
+     */
+    double zScale() const { return mZScale; }
+
+    /**
+     * Sets the z \a scale, which is a scaling factor which will be applied to z values from
+     * the layer.
+     *
+     * \note Any scaling specified via zScale() is applied before any offset value specified via zOffset()
+     *
+     * \see zScale()
+     */
+    void setZScale( double scale ) { mZScale = scale; }
+
+  private:
+
+    bool mEnabled = false;
+    double mZScale = 1.0;
+    double mZOffset = 0.0;
+};
+
+#endif // QGSRASTERLAYERELEVATIONPROPERTIES_H

src/ui/raster/qgsrasterelevationpropertieswidgetbase.ui

@@ -0,0 +1,136 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>QgsRasterElevationPropertiesWidgetBase</class>
+ <widget class="QWidget" name="QgsRasterElevationPropertiesWidgetBase">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>242</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Raster Elevation Properties</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
+    <number>0</number>
+   </property>
+   <item>
+    <widget class="QGroupBox" name="mElevationGroupBox">
+     <property name="focusPolicy">
+      <enum>Qt::StrongFocus</enum>
+     </property>
+     <property name="title">
+      <string>Represents Elevation Surface</string>
+     </property>
+     <property name="checkable">
+      <bool>true</bool>
+     </property>
+     <property name="syncGroup" stdset="0">
+      <string notr="true">vectorgeneral</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout_2">
+      <item row="3" column="0">
+       <widget class="Line" name="line_3">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="0">
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>Offset</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="label_2">
+        <property name="text">
+         <string>Scale</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="0" colspan="3">
+       <widget class="QLabel" name="label_3">
+        <property name="text">
+         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;&lt;span style=&quot; font-weight:600;&quot;&gt;Elevation scaling and offset can be used to manually correct elevation values from the layer.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;The scale is applied to the raster values before adding the offset.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1" colspan="2">
+       <widget class="QgsDoubleSpinBox" name="mScaleZSpinBox">
+        <property name="decimals">
+         <number>6</number>
+        </property>
+        <property name="minimum">
+         <double>0.000000000000000</double>
+        </property>
+        <property name="maximum">
+         <double>99999999999.000000000000000</double>
+        </property>
+        <property name="value">
+         <double>1.000000000000000</double>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1" colspan="2">
+       <widget class="QgsDoubleSpinBox" name="mOffsetZSpinBox">
+        <property name="decimals">
+         <number>6</number>
+        </property>
+        <property name="minimum">
+         <double>-99999999999.000000000000000</double>
+        </property>
+        <property name="maximum">
+         <double>99999999999.000000000000000</double>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <spacer name="verticalSpacer">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QgsDoubleSpinBox</class>
+   <extends>QDoubleSpinBox</extends>
+   <header>qgsdoublespinbox.h</header>
+  </customwidget>
+ </customwidgets>
+ <tabstops>
+  <tabstop>mElevationGroupBox</tabstop>
+  <tabstop>mScaleZSpinBox</tabstop>
+  <tabstop>mOffsetZSpinBox</tabstop>
+ </tabstops>
+ <resources/>
+ <connections/>
+</ui>

tests/src/python/CMakeLists.txt

@@ -272,6 +272,7 @@ ADD_PYTHON_TEST(PyQgsRasterBandComboBox test_qgsrasterbandcombobox.py)
 ADD_PYTHON_TEST(PyQgsRasterFileWriter test_qgsrasterfilewriter.py)
 ADD_PYTHON_TEST(PyQgsRasterFileWriterTask test_qgsrasterfilewritertask.py)
 ADD_PYTHON_TEST(PyQgsRasterLayer test_qgsrasterlayer.py)
+ADD_PYTHON_TEST(PyQgsRasterLayerElevationProperties test_qgsrasterlayerelevationproperties.py)
 ADD_PYTHON_TEST(PyQgsRasterLayerProperties test_qgsrasterlayerproperties.py)
 ADD_PYTHON_TEST(PyQgsRasterLayerRenderer test_qgsrasterlayerrenderer.py)
 ADD_PYTHON_TEST(PyQgsRasterColorRampShader test_qgsrastercolorrampshader.py)

tests/src/python/test_qgsrasterlayerelevationproperties.py

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsRasterLayerElevationProperties
+
+.. note:: This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+"""
+__author__ = 'Nyall Dawson'
+__date__ = '09/11/2020'
+__copyright__ = 'Copyright 2020, The QGIS Project'
+
+import qgis  # NOQA
+
+from qgis.core import (
+    QgsRasterLayerElevationProperties,
+    QgsReadWriteContext,
+)
+
+from qgis.PyQt.QtXml import QDomDocument
+
+from qgis.testing import start_app, unittest
+
+start_app()
+
+
+class TestQgsRasterLayerElevationProperties(unittest.TestCase):
+
+    def testBasic(self):
+        props = QgsRasterLayerElevationProperties(None)
+        self.assertEqual(props.zScale(), 1)
+        self.assertEqual(props.zOffset(), 0)
+        self.assertFalse(props.isEnabled())
+        self.assertFalse(props.hasElevation())
+
+        props.setZOffset(0.5)
+        props.setZScale(2)
+        props.setEnabled(True)
+        self.assertEqual(props.zScale(), 2)
+        self.assertEqual(props.zOffset(), 0.5)
+        self.assertTrue(props.isEnabled())
+        self.assertTrue(props.hasElevation())
+
+        doc = QDomDocument("testdoc")
+        elem = doc.createElement('test')
+        props.writeXml(elem, doc, QgsReadWriteContext())
+
+        props2 = QgsRasterLayerElevationProperties(None)
+        props2.readXml(elem, QgsReadWriteContext())
+        self.assertEqual(props2.zScale(), 2)
+        self.assertEqual(props2.zOffset(), 0.5)
+        self.assertTrue(props.isEnabled())
+
+
+if __name__ == '__main__':
+    unittest.main()