diff --git a/src/3d/mesh/qgsmeshterraingenerator.h b/src/3d/mesh/qgsmeshterraingenerator.h
index 9bedc140bf1..8841815e7e6 100644
--- a/src/3d/mesh/qgsmeshterraingenerator.h
+++ b/src/3d/mesh/qgsmeshterraingenerator.h
@@ -54,8 +54,7 @@ class _3D_EXPORT QgsMeshTerrainGenerator : public QgsTerrainGenerator
     //! Sets the symbol used to render the mesh as terrain
     void setSymbol( QgsMesh3DSymbol *symbol SIP_TRANSFER );
 
-    //! Sets CRS of the terrain
-    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
+    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context ) override;
 
     QgsChunkLoader *createChunkLoader( QgsChunkNode *node ) const override SIP_FACTORY;
     float rootChunkError( const Qgs3DMapSettings &map ) const override;
diff --git a/src/3d/qgs3dmapsettings.cpp b/src/3d/qgs3dmapsettings.cpp
index 29b7accc28b..917e5c79cef 100644
--- a/src/3d/qgs3dmapsettings.cpp
+++ b/src/3d/qgs3dmapsettings.cpp
@@ -21,9 +21,7 @@
 #include "qgsflatterraingenerator.h"
 #include "qgsdemterraingenerator.h"
 #include "qgsmeshterraingenerator.h"
-#include "qgsonlineterraingenerator.h"
 #include "qgsprojectviewsettings.h"
-#include "qgsquantizedmeshterraingenerator.h"
 #include "qgsprojectelevationproperties.h"
 #include "qgsterrainprovider.h"
 #include "qgslightsource.h"
@@ -244,35 +242,13 @@ void Qgs3DMapSettings::readXml( const QDomElement &elem, const QgsReadWriteConte
   mLayers = mapLayers; // needs to resolve refs afterwards
 
   QDomElement elemTerrainGenerator = elemTerrain.firstChildElement( QStringLiteral( "generator" ) );
-  QString terrainGenType = elemTerrainGenerator.attribute( QStringLiteral( "type" ) );
-  if ( terrainGenType == QLatin1String( "dem" ) )
+  const QString terrainGenType = elemTerrainGenerator.attribute( QStringLiteral( "type" ) );
+  std::unique_ptr< QgsTerrainGenerator > terrainGenerator( Qgs3D::terrainRegistry()->createTerrainGenerator( terrainGenType ) );
+  if ( terrainGenerator )
   {
-    QgsDemTerrainGenerator *demTerrainGenerator = new QgsDemTerrainGenerator;
-    demTerrainGenerator->setCrs( mCrs, mTransformContext );
-    setTerrainGenerator( demTerrainGenerator );
-  }
-  else if ( terrainGenType == QLatin1String( "online" ) )
-  {
-    QgsOnlineTerrainGenerator *onlineTerrainGenerator = new QgsOnlineTerrainGenerator;
-    onlineTerrainGenerator->setCrs( mCrs, mTransformContext );
-    setTerrainGenerator( onlineTerrainGenerator );
-  }
-  else if ( terrainGenType == QLatin1String( "mesh" ) )
-  {
-    QgsMeshTerrainGenerator *meshTerrainGenerator = new QgsMeshTerrainGenerator;
-    meshTerrainGenerator->setCrs( mCrs, mTransformContext );
-    setTerrainGenerator( meshTerrainGenerator );
-  }
-  else if ( terrainGenType == QLatin1String( "quantizedmesh" ) )
-  {
-    QgsQuantizedMeshTerrainGenerator *qmTerrainGenerator = new QgsQuantizedMeshTerrainGenerator;
-    setTerrainGenerator( qmTerrainGenerator );
-  }
-  else // "flat"
-  {
-    QgsFlatTerrainGenerator *flatGen = new QgsFlatTerrainGenerator;
-    flatGen->setCrs( mCrs );
-    setTerrainGenerator( flatGen );
+    terrainGenerator->setCrs( mCrs, mTransformContext );
+    mTerrainGenerator->readXml( elemTerrainGenerator );
+    setTerrainGenerator( terrainGenerator.release() );
   }
 
   std::unique_ptr<QgsAbstractTerrainSettings> terrainSettings( Qgs3D::terrainRegistry()->createTerrainSettings( terrainGenType ) );
@@ -282,8 +258,6 @@ void Qgs3DMapSettings::readXml( const QDomElement &elem, const QgsReadWriteConte
     setTerrainSettings( terrainSettings.release() );
   }
 
-  mTerrainGenerator->readXml( elemTerrainGenerator );
-
   QDomElement elemSkybox = elem.firstChildElement( QStringLiteral( "skybox" ) );
   mIsSkyboxEnabled = elemSkybox.attribute( QStringLiteral( "skybox-enabled" ) ).toInt();
   mSkyboxSettings.readXml( elemSkybox, context );
@@ -687,7 +661,7 @@ void Qgs3DMapSettings::configureTerrainFromProject( QgsProjectElevationPropertie
   if ( properties->terrainProvider()->type() == QLatin1String( "flat" ) )
   {
     QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-    flatTerrain->setCrs( crs() );
+    flatTerrain->setCrs( crs(), QgsProject::instance()->transformContext() );
     setTerrainGenerator( flatTerrain );
 
     setTerrainElevationOffset( properties->terrainProvider()->offset() );
@@ -722,7 +696,7 @@ void Qgs3DMapSettings::configureTerrainFromProject( QgsProjectElevationPropertie
   else
   {
     QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-    flatTerrain->setCrs( crs() );
+    flatTerrain->setCrs( crs(), QgsProject::instance()->transformContext() );
     setTerrainGenerator( flatTerrain );
   }
 }
diff --git a/src/3d/terrain/qgsdemterraingenerator.h b/src/3d/terrain/qgsdemterraingenerator.h
index 217cff1004c..f94f3e10738 100644
--- a/src/3d/terrain/qgsdemterraingenerator.h
+++ b/src/3d/terrain/qgsdemterraingenerator.h
@@ -52,8 +52,7 @@ class _3D_EXPORT QgsDemTerrainGenerator : public QgsTerrainGenerator
     //! Returns raster layer with elevation model to be used for terrain generation
     QgsRasterLayer *layer() const;
 
-    //! Sets CRS of the terrain
-    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
+    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context ) override;
     QgsCoordinateReferenceSystem crs() const override { return mCrs; }
 
     //! Sets resolution of the generator (how many elevation samples on one side of a terrain tile)
diff --git a/src/3d/terrain/qgsflatterraingenerator.cpp b/src/3d/terrain/qgsflatterraingenerator.cpp
index 0d130a75e92..2a270d731fa 100644
--- a/src/3d/terrain/qgsflatterraingenerator.cpp
+++ b/src/3d/terrain/qgsflatterraingenerator.cpp
@@ -131,7 +131,7 @@ void QgsFlatTerrainGenerator::readXml( const QDomElement &elem )
   Q_UNUSED( elem )
 }
 
-void QgsFlatTerrainGenerator::setCrs( const QgsCoordinateReferenceSystem &crs )
+void QgsFlatTerrainGenerator::setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext & )
 {
   mCrs = crs;
   updateTilingScheme();
diff --git a/src/3d/terrain/qgsflatterraingenerator.h b/src/3d/terrain/qgsflatterraingenerator.h
index b337b0cce37..ce914f81d04 100644
--- a/src/3d/terrain/qgsflatterraingenerator.h
+++ b/src/3d/terrain/qgsflatterraingenerator.h
@@ -69,9 +69,7 @@ class _3D_EXPORT QgsFlatTerrainGenerator : public QgsTerrainGenerator
     void writeXml( QDomElement &elem ) const override;
     void readXml( const QDomElement &elem ) override;
 
-    //! Sets CRS of the terrain
-    void setCrs( const QgsCoordinateReferenceSystem &crs );
-    //! Returns CRS of the terrain
+    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context ) override;
     QgsCoordinateReferenceSystem crs() const override { return mCrs; }
 
   private:
diff --git a/src/3d/terrain/qgsonlineterraingenerator.h b/src/3d/terrain/qgsonlineterraingenerator.h
index 26e922f64d1..3b6e9e851dd 100644
--- a/src/3d/terrain/qgsonlineterraingenerator.h
+++ b/src/3d/terrain/qgsonlineterraingenerator.h
@@ -46,9 +46,7 @@ class _3D_EXPORT QgsOnlineTerrainGenerator : public QgsTerrainGenerator
     QgsOnlineTerrainGenerator();
     ~QgsOnlineTerrainGenerator() override;
 
-    //! Sets CRS of the terrain
-    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
-    //! Returns CRS of the terrain
+    void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context ) override;
     QgsCoordinateReferenceSystem crs() const override { return mCrs; }
 
     //! Sets resolution of the generator (how many elevation samples on one side of a terrain tile)
diff --git a/src/3d/terrain/qgsterraingenerator.cpp b/src/3d/terrain/qgsterraingenerator.cpp
index fe1bc6f3fe0..e446e3a87ba 100644
--- a/src/3d/terrain/qgsterraingenerator.cpp
+++ b/src/3d/terrain/qgsterraingenerator.cpp
@@ -71,6 +71,11 @@ QString QgsTerrainGenerator::typeToString( QgsTerrainGenerator::Type type )
   return QString();
 }
 
+void QgsTerrainGenerator::setCrs( const QgsCoordinateReferenceSystem &, const QgsCoordinateTransformContext & )
+{
+
+}
+
 bool QgsTerrainGenerator::isValid() const
 {
   return mIsValid;
diff --git a/src/3d/terrain/qgsterraingenerator.h b/src/3d/terrain/qgsterraingenerator.h
index 68ccbd8a781..44cac853ab5 100644
--- a/src/3d/terrain/qgsterraingenerator.h
+++ b/src/3d/terrain/qgsterraingenerator.h
@@ -26,6 +26,7 @@ class Qgs3DMapSettings;
 class Qgs3DRenderContext;
 class QgsRectangle;
 class QgsTerrainEntity;
+class QgsCoordinateTransformContext;
 
 class QDomElement;
 class QDomDocument;
@@ -105,6 +106,13 @@ class _3D_EXPORT QgsTerrainGenerator : public QgsQuadtreeChunkLoaderFactory
     //! Returns tiling scheme of the terrain
     const QgsTilingScheme &tilingScheme() const { return mTerrainTilingScheme; }
 
+    /**
+     * Sets the CRS associated with the terrain.
+     *
+     * \see crs()
+     */
+    virtual void setCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
+
     //! Returns CRS of the terrain
     virtual QgsCoordinateReferenceSystem crs() const { return mTerrainTilingScheme.crs(); }
 
diff --git a/src/app/3d/qgs3dmapconfigwidget.cpp b/src/app/3d/qgs3dmapconfigwidget.cpp
index e4175795dda..0f45798a607 100644
--- a/src/app/3d/qgs3dmapconfigwidget.cpp
+++ b/src/app/3d/qgs3dmapconfigwidget.cpp
@@ -263,7 +263,7 @@ void Qgs3DMapConfigWidget::apply()
     case QgsTerrainGenerator::Flat:
     {
       QgsFlatTerrainGenerator *flatTerrainGen = new QgsFlatTerrainGenerator;
-      flatTerrainGen->setCrs( mMap->crs() );
+      flatTerrainGen->setCrs( mMap->crs(), QgsProject::instance()->transformContext() );
       mMap->setTerrainGenerator( flatTerrainGen );
     }
     break;
diff --git a/tests/src/3d/sandbox/qgis_3d_sandbox.cpp b/tests/src/3d/sandbox/qgis_3d_sandbox.cpp
index ec8504fcd82..b1e4e2fd89d 100644
--- a/tests/src/3d/sandbox/qgis_3d_sandbox.cpp
+++ b/tests/src/3d/sandbox/qgis_3d_sandbox.cpp
@@ -84,7 +84,7 @@ void initCanvas3D( Qgs3DMapCanvas *canvas )
   } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
   map->setTerrainElevationOffset( QgsProject::instance()->elevationProperties()->terrainProvider()->offset() );
 
diff --git a/tests/src/3d/testqgs3dcameracontroller.cpp b/tests/src/3d/testqgs3dcameracontroller.cpp
index d8bd5a4f695..7f2bb10b2a2 100644
--- a/tests/src/3d/testqgs3dcameracontroller.cpp
+++ b/tests/src/3d/testqgs3dcameracontroller.cpp
@@ -99,7 +99,7 @@ void TestQgs3DCameraController::testTranslate()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -172,7 +172,7 @@ void TestQgs3DCameraController::testZoom()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -245,7 +245,7 @@ void TestQgs3DCameraController::testZoomWheel()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -292,7 +292,7 @@ void TestQgs3DCameraController::testRotationCenter()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -367,7 +367,7 @@ void TestQgs3DCameraController::testRotationCamera()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -443,7 +443,7 @@ void TestQgs3DCameraController::testRotationCenterZoomWheelRotationCenter()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -586,7 +586,7 @@ void TestQgs3DCameraController::testTranslateRotationCenterTranslate()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -739,7 +739,7 @@ void TestQgs3DCameraController::testTranslateZoomWheelTranslate()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -883,7 +883,7 @@ void TestQgs3DCameraController::testTranslateRotationCameraTranslate()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
@@ -1034,7 +1034,7 @@ void TestQgs3DCameraController::testRotationCenterRotationCameraRotationCenter()
   mapSettings->setLayers( QList<QgsMapLayer *>() << mLayerRgb << mLayerBuildings );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), QgsCoordinateTransformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QPoint winSize = QPoint( 640, 480 ); // default window size
diff --git a/tests/src/3d/testqgs3drendering.cpp b/tests/src/3d/testqgs3drendering.cpp
index 3e462f32a29..4a33552408a 100644
--- a/tests/src/3d/testqgs3drendering.cpp
+++ b/tests/src/3d/testqgs3drendering.cpp
@@ -281,7 +281,7 @@ void TestQgs3DRendering::testFlatTerrain()
   map->setLayers( QList<QgsMapLayer *>() << mLayerRgb );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -414,7 +414,7 @@ void TestQgs3DRendering::testExtrudedPolygons()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -461,7 +461,7 @@ void TestQgs3DRendering::testExtrudedPolygonsClipping()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -517,7 +517,7 @@ void TestQgs3DRendering::testPhongShading()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -569,7 +569,7 @@ void TestQgs3DRendering::testExtrudedPolygonsTexturedPhong()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -623,7 +623,7 @@ void TestQgs3DRendering::testExtrudedPolygonsDataDefinedPhong()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -677,7 +677,7 @@ void TestQgs3DRendering::testExtrudedPolygonsDataDefinedPhongClipping()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -740,7 +740,7 @@ void TestQgs3DRendering::testExtrudedPolygonsDataDefinedGooch()
   mapSettings->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), mProject->transformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -796,7 +796,7 @@ void TestQgs3DRendering::testExtrudedPolygonsDataDefinedGoochClipping()
   mapSettings->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), mProject->transformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -837,7 +837,7 @@ void TestQgs3DRendering::testExtrudedPolygonsGoochShading()
   map->setLayers( QList<QgsMapLayer *>() << mLayerBuildings << mLayerRgb );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -897,7 +897,7 @@ void TestQgs3DRendering::testExtrudedPolygonsMetalRoughShading()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -949,7 +949,7 @@ void TestQgs3DRendering::testPolygonsEdges()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -999,7 +999,7 @@ void TestQgs3DRendering::testLineRendering()
   map->setLayers( QList<QgsMapLayer *>() << layerLines );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1056,7 +1056,7 @@ void TestQgs3DRendering::testLineRenderingClipping()
   map->setLayers( QList<QgsMapLayer *>() << layerLines );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1115,7 +1115,7 @@ void TestQgs3DRendering::testLineRenderingCurved()
   map->setLayers( QList<QgsMapLayer *>() << layerLines );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1174,7 +1174,7 @@ void TestQgs3DRendering::testLineRenderingDataDefinedColors()
   map->setLayers( QList<QgsMapLayer *>() << layerLines );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1218,7 +1218,7 @@ void TestQgs3DRendering::testBufferedLineRendering()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1265,7 +1265,7 @@ void TestQgs3DRendering::testBufferedLineRenderingClipping()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1325,7 +1325,7 @@ void TestQgs3DRendering::testBufferedLineRenderingWidth()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1360,7 +1360,7 @@ void TestQgs3DRendering::testMapTheme()
   map->setTerrainMapTheme( "theme_dtm" );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1416,7 +1416,7 @@ void TestQgs3DRendering::testRuleBasedRenderer()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1475,7 +1475,7 @@ void TestQgs3DRendering::testFilteredRuleBasedRenderer()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1507,7 +1507,7 @@ void TestQgs3DRendering::testAnimationExport()
   map.setExtent( fullExtent );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map.crs() );
+  flatTerrain->setCrs( map.crs(), mProject->transformContext() );
   map.setTerrainGenerator( flatTerrain );
 
   Qgs3DAnimationSettings animSettings;
@@ -1578,7 +1578,7 @@ void TestQgs3DRendering::testInstancedRendering()
   mapSettings->setLayers( QList<QgsMapLayer *>() << layerPointsZ.get() );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), mapSettings->transformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1653,7 +1653,7 @@ void TestQgs3DRendering::testInstancedRenderingClipping()
   mapSettings->setLayers( QList<QgsMapLayer *>() << layerPointsZ.get() );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( mapSettings->crs() );
+  flatTerrain->setCrs( mapSettings->crs(), mapSettings->transformContext() );
   mapSettings->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1754,7 +1754,7 @@ void TestQgs3DRendering::testBillboardRendering()
   map->setLayers( QList<QgsMapLayer *>() << layerPointsZ.get() );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1845,7 +1845,7 @@ void TestQgs3DRendering::testFilteredFlatTerrain()
   map->setLayers( QList<QgsMapLayer *>() << mLayerRgb );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -1941,7 +1941,7 @@ void TestQgs3DRendering::testFilteredExtrudedPolygons()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), map->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
diff --git a/tests/src/3d/testqgslayout3dmap.cpp b/tests/src/3d/testqgslayout3dmap.cpp
index 053f49a36ab..abaf85bbc83 100644
--- a/tests/src/3d/testqgslayout3dmap.cpp
+++ b/tests/src/3d/testqgslayout3dmap.cpp
@@ -86,7 +86,7 @@ void TestQgsLayout3DMap::testBasic()
   map->setLayers( QList<QgsMapLayer *>() << mLayerDtm );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsCameraPose cam;
diff --git a/tests/src/3d/testqgsmesh3drendering.cpp b/tests/src/3d/testqgsmesh3drendering.cpp
index 1da99ee46aa..0fb7b2c5d0b 100644
--- a/tests/src/3d/testqgsmesh3drendering.cpp
+++ b/tests/src/3d/testqgsmesh3drendering.cpp
@@ -155,7 +155,7 @@ void TestQgsMesh3DRendering::testMesh()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -197,7 +197,7 @@ void TestQgsMesh3DRendering::testMesh_datasetOnFaces()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -309,7 +309,7 @@ void TestQgsMesh3DRendering::testFilteredMesh()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;
@@ -350,7 +350,7 @@ void TestQgsMesh3DRendering::testMeshClipping()
   map->setLightSources( { defaultLight.clone() } );
 
   QgsFlatTerrainGenerator *flatTerrain = new QgsFlatTerrainGenerator;
-  flatTerrain->setCrs( map->crs() );
+  flatTerrain->setCrs( map->crs(), mProject->transformContext() );
   map->setTerrainGenerator( flatTerrain );
 
   QgsOffscreen3DEngine engine;