[FEATURE] Optionally use a map theme to render terrain textures

Often it is useful to have a different map theme for terrain in 3D view
than the map theme used in the main map canvas.

src/3d/qgs3dmapsettings.cpp

@@ -39,6 +39,7 @@ Qgs3DMapSettings::Qgs3DMapSettings( const Qgs3DMapSettings &other )
   , mMaxTerrainGroundError( other.mMaxTerrainGroundError )
   , mTerrainShadingEnabled( other.mTerrainShadingEnabled )
   , mTerrainShadingMaterial( other.mTerrainShadingMaterial )
+  , mTerrainMapTheme( other.mTerrainMapTheme )
   , mShowTerrainBoundingBoxes( other.mShowTerrainBoundingBoxes )
   , mShowTerrainTileInfo( other.mShowTerrainTileInfo )
   , mShowCameraViewCenter( other.mShowCameraViewCenter )
@@ -87,6 +88,7 @@ void Qgs3DMapSettings::readXml( const QDomElement &elem, const QgsReadWriteConte
   QDomElement elemTerrainShadingMaterial = elemTerrain.firstChildElement( QStringLiteral( "shading-material" ) );
   if ( !elemTerrainShadingMaterial.isNull() )
     mTerrainShadingMaterial.readXml( elemTerrainShadingMaterial );
+  mTerrainMapTheme = elemTerrain.attribute( QStringLiteral( "map-theme" ) );
   mShowLabels = elemTerrain.attribute( QStringLiteral( "show-labels" ), QStringLiteral( "0" ) ).toInt();
 
   mPointLights.clear();
@@ -204,6 +206,7 @@ QDomElement Qgs3DMapSettings::writeXml( QDomDocument &doc, const QgsReadWriteCon
   QDomElement elemTerrainShadingMaterial = doc.createElement( QStringLiteral( "shading-material" ) );
   mTerrainShadingMaterial.writeXml( elemTerrainShadingMaterial );
   elemTerrain.appendChild( elemTerrainShadingMaterial );
+  elemTerrain.setAttribute( QStringLiteral( "map-theme" ), mTerrainMapTheme );
   elemTerrain.setAttribute( QStringLiteral( "show-labels" ), mShowLabels ? 1 : 0 );
 
   QDomElement elemPointLights = doc.createElement( QStringLiteral( "point-lights" ) );
@@ -432,6 +435,15 @@ void Qgs3DMapSettings::setTerrainShadingMaterial( const QgsPhongMaterialSettings
   emit terrainShadingChanged();
 }
 
+void Qgs3DMapSettings::setTerrainMapTheme( const QString &theme )
+{
+  if ( mTerrainMapTheme == theme )
+    return;
+
+  mTerrainMapTheme = theme;
+  emit terrainMapThemeChanged();
+}
+
 void Qgs3DMapSettings::setRenderers( const QList<QgsAbstract3DRenderer *> &renderers )
 {
   mRenderers = renderers;

src/3d/qgs3dmapsettings.h

@@ -148,9 +148,16 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
     //! Returns vertical scale (exaggeration) of terrain
     double terrainVerticalScale() const;
 
-    //! Sets the list of map layers to be rendered as a texture of the terrain
+    /**
+     * Sets the list of map layers to be rendered as a texture of the terrain
+     * \note If terrain map theme is set, it has a priority over the list of layers specified here.
+     */
     void setLayers( const QList<QgsMapLayer *> &layers );
-    //! Returns the list of map layers to be rendered as a texture of the terrain
+
+    /**
+     * Returns the list of map layers to be rendered as a texture of the terrain
+     * \note If terrain map theme is set, it has a priority over the list of layers specified here.
+     */
     QList<QgsMapLayer *> layers() const;
 
     /**
@@ -231,6 +238,24 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
      */
     QgsPhongMaterialSettings terrainShadingMaterial() const { return mTerrainShadingMaterial; }
 
+    /**
+     * Sets name of the map theme.
+     * \see terrainMapTheme()
+     * \since QGIS 3.6
+     */
+    void setTerrainMapTheme( const QString &theme );
+
+    /**
+     * Returns name of the map theme (from the active project) that will be used for terrain's texture.
+     * Empty map theme name means that the map theme is not overridden and the current map theme will be used.
+     * \since QGIS 3.6
+     */
+    QString terrainMapTheme() const { return mTerrainMapTheme; }
+
+    //
+    // misc configuration
+    //
+
     //! Sets list of extra 3D renderers to use in the scene. Takes ownership of the objects.
     void setRenderers( const QList<QgsAbstract3DRenderer *> &renderers SIP_TRANSFER );
     //! Returns list of extra 3D renderers
@@ -310,6 +335,12 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
      * \since QGIS 3.6
      */
     void terrainShadingChanged();
+
+    /**
+     * Emitted when terrain's map theme has changed
+     * \since QGIS 3.6
+     */
+    void terrainMapThemeChanged();
     //! Emitted when the flag whether terrain's bounding boxes are shown has changed
     void showTerrainBoundingBoxesChanged();
     //! Emitted when the flag whether terrain's tile info is shown has changed
@@ -342,6 +373,7 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
     float mMaxTerrainGroundError = 1.f;  //!< Maximum allowed horizontal map error in map units (determines how many zoom levels will be used)
     bool mTerrainShadingEnabled = false;   //!< Whether terrain should be shaded taking lights into account
     QgsPhongMaterialSettings mTerrainShadingMaterial;  //!< Material to use for the terrain (if shading is enabled). Diffuse color is ignored.
+    QString mTerrainMapTheme;  //!< Name of map theme used for terrain's texture (empty means use the current map theme)
     bool mShowTerrainBoundingBoxes = false;  //!< Whether to show bounding boxes of entities - useful for debugging
     bool mShowTerrainTileInfo = false;  //!< Whether to draw extra information about terrain tiles to the textures - useful for debugging
     bool mShowCameraViewCenter = false;  //!< Whether to show camera view center as a sphere - useful for debugging

src/3d/terrain/qgsterrainentity_p.cpp

@@ -69,6 +69,7 @@ QgsTerrainEntity::QgsTerrainEntity( int maxLevel, const Qgs3DMapSettings &map, Q
   connect( &map, &Qgs3DMapSettings::showLabelsChanged, this, &QgsTerrainEntity::invalidateMapImages );
   connect( &map, &Qgs3DMapSettings::layersChanged, this, &QgsTerrainEntity::onLayersChanged );
   connect( &map, &Qgs3DMapSettings::backgroundColorChanged, this, &QgsTerrainEntity::invalidateMapImages );
+  connect( &map, &Qgs3DMapSettings::terrainMapThemeChanged, this, &QgsTerrainEntity::invalidateMapImages );
 
   connectToLayersRepaintRequest();
 

src/3d/terrain/qgsterraintexturegenerator_p.cpp

@@ -18,6 +18,7 @@
 #include <qgsmaprenderercustompainterjob.h>
 #include <qgsmaprenderersequentialjob.h>
 #include <qgsmapsettings.h>
+#include <qgsmapthemecollection.h>
 #include <qgsproject.h>
 
 #include "qgs3dmapsettings.h"
@@ -127,13 +128,26 @@ void QgsTerrainTextureGenerator::onRenderingFinished()
 QgsMapSettings QgsTerrainTextureGenerator::baseMapSettings()
 {
   QgsMapSettings mapSettings;
-  mapSettings.setLayers( mMap.layers() );
+
   mapSettings.setOutputSize( QSize( mMap.mapTileResolution(), mMap.mapTileResolution() ) );
   mapSettings.setDestinationCrs( mMap.crs() );
   mapSettings.setBackgroundColor( mMap.backgroundColor() );
   mapSettings.setFlag( QgsMapSettings::DrawLabeling, mMap.showLabels() );
   mapSettings.setTransformContext( mMap.transformContext() );
   mapSettings.setPathResolver( mMap.pathResolver() );
+
+  QgsMapThemeCollection *mapThemes = QgsProject::instance()->mapThemeCollection();
+  QString mapThemeName = mMap.terrainMapTheme();
+  if ( mapThemeName.isEmpty() || !mapThemes->hasMapTheme( mapThemeName ) )
+  {
+    mapSettings.setLayers( mMap.layers() );
+  }
+  else
+  {
+    mapSettings.setLayers( mapThemes->mapThemeVisibleLayers( mapThemeName ) );
+    mapSettings.setLayerStyleOverrides( mapThemes->mapThemeStyleOverrides( mapThemeName ) );
+  }
+
   return mapSettings;
 }
 

src/app/3d/qgs3dmapconfigwidget.cpp

@@ -21,8 +21,9 @@
 #include "qgs3dutils.h"
 
 #include "qgsmapcanvas.h"
+#include "qgsmapthemecollection.h"
 #include "qgsrasterlayer.h"
-//#include "qgsproject.h"
+#include "qgsproject.h"
 
 Qgs3DMapConfigWidget::Qgs3DMapConfigWidget( Qgs3DMapSettings *map, QgsMapCanvas *mainCanvas, QWidget *parent )
   : QWidget( parent )
@@ -73,6 +74,14 @@ Qgs3DMapConfigWidget::Qgs3DMapConfigWidget( Qgs3DMapSettings *map, QgsMapCanvas
   widgetTerrainMaterial->setDiffuseVisible( false );
   widgetTerrainMaterial->setMaterial( mMap->terrainShadingMaterial() );
 
+  // populate combo box with map themes
+  const QStringList mapThemeNames = QgsProject::instance()->mapThemeCollection()->mapThemes();
+  cboTerrainMapTheme->addItem( QString() );  // empty item for no map theme
+  for ( QString themeName : mapThemeNames )
+    cboTerrainMapTheme->addItem( themeName );
+
+  cboTerrainMapTheme->setCurrentText( mMap->terrainMapTheme() );
+
   widgetLights->setPointLights( mMap->pointLights() );
 
   connect( cboTerrainLayer, static_cast<void ( QComboBox::* )( int )>( &QgsMapLayerComboBox::currentIndexChanged ), this, &Qgs3DMapConfigWidget::onTerrainLayerChanged );
@@ -144,6 +153,8 @@ void Qgs3DMapConfigWidget::apply()
   mMap->setTerrainShadingEnabled( groupTerrainShading->isChecked() );
   mMap->setTerrainShadingMaterial( widgetTerrainMaterial->material() );
 
+  mMap->setTerrainMapTheme( cboTerrainMapTheme->currentText() );
+
   mMap->setPointLights( widgetLights->pointLights() );
 }
 

src/ui/3d/map3dconfigwidget.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>691</width>
-    <height>1135</height>
+    <height>1122</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -15,7 +15,7 @@
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
-    <widget class="QGroupBox" name="groupBox">
+    <widget class="QgsCollapsibleGroupBox" name="groupTerrain">
      <property name="title">
       <string>Terrain</string>
      </property>
@@ -84,6 +84,20 @@
         </property>
        </widget>
       </item>
+      <item row="4" column="0">
+       <widget class="QLabel" name="label_9">
+        <property name="text">
+         <string>Map theme</string>
+        </property>
+       </widget>
+      </item>
+      <item row="4" column="1" colspan="2">
+       <widget class="QComboBox" name="cboTerrainMapTheme">
+        <property name="editable">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>
@@ -275,12 +289,15 @@
   <tabstop>spinTerrainScale</tabstop>
   <tabstop>spinTerrainResolution</tabstop>
   <tabstop>spinTerrainSkirtHeight</tabstop>
+  <tabstop>cboTerrainMapTheme</tabstop>
+  <tabstop>groupTerrainShading</tabstop>
   <tabstop>spinMapResolution</tabstop>
   <tabstop>spinScreenError</tabstop>
   <tabstop>spinGroundError</tabstop>
   <tabstop>chkShowLabels</tabstop>
   <tabstop>chkShowTileInfo</tabstop>
   <tabstop>chkShowBoundingBoxes</tabstop>
+  <tabstop>chkShowCameraViewCenter</tabstop>
  </tabstops>
  <resources/>
  <connections/>