Make coordinates of vector data chunks independent from scene origin

python/3d/auto_generated/symbols/qgspoint3dsymbol.sip.in

@@ -191,9 +191,9 @@ Returns transform for individual objects represented by the symbol
 Sets transform for individual objects represented by the symbol
 %End
 
-    QMatrix4x4 billboardTransform() const;
+    float billboardHeight() const;
 %Docstring
-Returns transform for billboards
+Returns how much the billboard should be elevated upwards
 %End
 
   private:

python/PyQt6/3d/auto_generated/symbols/qgspoint3dsymbol.sip.in

@@ -191,9 +191,9 @@ Returns transform for individual objects represented by the symbol
 Sets transform for individual objects represented by the symbol
 %End
 
-    QMatrix4x4 billboardTransform() const;
+    float billboardHeight() const;
 %Docstring
-Returns transform for billboards
+Returns how much the billboard should be elevated upwards
 %End
 
   private:

src/3d/qgs3dutils.cpp

@@ -488,7 +488,7 @@ QMatrix4x4 Qgs3DUtils::stringToMatrix4x4( const QString &str )
   return m;
 }
 
-void Qgs3DUtils::extractPointPositions( const QgsFeature &f, const Qgs3DRenderContext &context, Qgis::AltitudeClamping altClamp, QVector<QVector3D> &positions )
+void Qgs3DUtils::extractPointPositions( const QgsFeature &f, const Qgs3DRenderContext &context, const QgsVector3D &chunkOrigin, Qgis::AltitudeClamping altClamp, QVector<QVector3D> &positions )
 {
   const QgsAbstractGeometry *g = f.geometry().constGet();
   for ( auto it = g->vertices_begin(); it != g->vertices_end(); ++it )
@@ -513,7 +513,10 @@ void Qgs3DUtils::extractPointPositions( const QgsFeature &f, const Qgs3DRenderCo
         h = terrainZ + geomZ;
         break;
     }
-    positions.append( QVector3D( pt.x() - context.origin().x(), h, -( pt.y() - context.origin().y() ) ) );
+    positions.append( QVector3D(
+                        static_cast<float>( pt.x() - chunkOrigin.x() ),
+                        static_cast<float>( pt.y() - chunkOrigin.y() ),
+                        h ) );
     QgsDebugMsgLevel( QStringLiteral( "%1 %2 %3" ).arg( positions.last().x() ).arg( positions.last().y() ).arg( positions.last().z() ), 2 );
   }
 }

src/3d/qgs3dutils.h

@@ -143,7 +143,7 @@ class _3D_EXPORT Qgs3DUtils
     static QMatrix4x4 stringToMatrix4x4( const QString &str );
 
     //! Calculates (x,y,z) positions of (multi)point from the given feature
-    static void extractPointPositions( const QgsFeature &f, const Qgs3DRenderContext &context, Qgis::AltitudeClamping altClamp, QVector<QVector3D> &positions );
+    static void extractPointPositions( const QgsFeature &f, const Qgs3DRenderContext &context, const QgsVector3D &chunkOrigin, Qgis::AltitudeClamping altClamp, QVector<QVector3D> &positions );
 
     /**
      * Returns TRUE if bbox is completely outside the current viewing volume.

src/3d/qgsfeature3dhandler_p.cpp

@@ -28,10 +28,10 @@ void QgsFeature3DHandler::updateZRangeFromPositions( const QVector<QVector3D> &p
 {
   for ( const QVector3D &pos : positions )
   {
-    if ( pos.y() < mZMin )
-      mZMin = pos.y();
-    if ( pos.y() > mZMax )
-      mZMax = pos.y();
+    if ( pos.z() < mZMin )
+      mZMin = pos.z();
+    if ( pos.z() > mZMax )
+      mZMax = pos.z();
   }
 }
 

src/3d/qgsfeature3dhandler_p.h

@@ -49,7 +49,7 @@ class QgsFeature3DHandler
      * Called before feature iteration starts to initialize, get required attributes.
      * \returns TRUE on success (on FALSE the handler failed to initialize and processFeature() / finalize() should not be called
      */
-    virtual bool prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames ) = 0;
+    virtual bool prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsVector3D &chunkOrigin ) = 0;
 
     /**
      * Called for every feature to extract information out of it into some

src/3d/qgsrubberband3d.cpp

@@ -80,6 +80,10 @@ QgsRubberBand3D::QgsRubberBand3D( Qgs3DMapSettings &map, QgsWindow3DEngine *engi
 
   mLineEntity->addComponent( mLineMaterial );
 
+  Qt3DCore::QTransform *lineTransform = new Qt3DCore::QTransform;
+  lineTransform->setRotation( QQuaternion::fromAxisAndAngle( QVector3D( 1, 0, 0 ), -90 ) ); // flip map (x,y,z) to world (x,z,-y)
+  mLineEntity->addComponent( lineTransform );
+
   // Rubberband vertex markers
   mMarkerEntity = new Qt3DCore::QEntity( parentEntity );
   mMarkerGeometry = new QgsBillboardGeometry();
@@ -99,6 +103,10 @@ QgsRubberBand3D::QgsRubberBand3D( Qgs3DMapSettings &map, QgsWindow3DEngine *engi
   mMarkerSymbol = QgsMarkerSymbol::createSimple( props );
   updateMarkerMaterial();
   mMarkerEntity->addComponent( mMarkerGeometryRenderer );
+
+  Qt3DCore::QTransform *markerTransform = new Qt3DCore::QTransform;
+  markerTransform->setRotation( QQuaternion::fromAxisAndAngle( QVector3D( 1, 0, 0 ), -90 ) ); // flip map (x,y,z) to world (x,z,-y)
+  mMarkerEntity->addComponent( markerTransform );
 }
 
 QgsRubberBand3D::~QgsRubberBand3D()
@@ -167,7 +175,7 @@ void QgsRubberBand3D::updateGeometry()
 {
   QgsLineVertexData lineData;
   lineData.withAdjacency = true;
-  lineData.init( Qgis::AltitudeClamping::Absolute, Qgis::AltitudeBinding::Vertex, 0, Qgs3DRenderContext::fromMapSettings( mMapSettings ) );
+  lineData.init( Qgis::AltitudeClamping::Absolute, Qgis::AltitudeBinding::Vertex, 0, Qgs3DRenderContext::fromMapSettings( mMapSettings ), mMapSettings->origin() );
   lineData.addLineString( mLineString );
 
   mPositionAttribute->buffer()->setData( lineData.createVertexBuffer() );

src/3d/qgsrulebased3drenderer.cpp

@@ -262,12 +262,12 @@ void QgsRuleBased3DRenderer::Rule::createHandlers( QgsVectorLayer *layer, QgsRul
 }
 
 
-void QgsRuleBased3DRenderer::Rule::prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, QgsRuleBased3DRenderer::RuleToHandlerMap &handlers ) const
+void QgsRuleBased3DRenderer::Rule::prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsVector3D &chunkOrigin,  QgsRuleBased3DRenderer::RuleToHandlerMap &handlers ) const
 {
   if ( mSymbol )
   {
     QgsFeature3DHandler *handler = handlers[this];
-    if ( !handler->prepare( context, attributeNames ) )
+    if ( !handler->prepare( context, attributeNames, chunkOrigin ) )
     {
       handlers.remove( this );
       delete handler;
@@ -283,7 +283,7 @@ void QgsRuleBased3DRenderer::Rule::prepare( const Qgs3DRenderContext &context, Q
   // call recursively
   for ( Rule *rule : std::as_const( mChildren ) )
   {
-    rule->prepare( context, attributeNames, handlers );
+    rule->prepare( context, attributeNames, chunkOrigin, handlers );
   }
 }
 

src/3d/qgsrulebased3drenderer.h

@@ -242,7 +242,7 @@ class _3D_EXPORT QgsRuleBased3DRenderer : public QgsAbstractVectorLayer3DRendere
          * call prepare() on handlers and populate attributeNames
          * \note not available in Python bindings
          */
-        void prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, RuleToHandlerMap &handlers ) const SIP_SKIP;
+        void prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsVector3D &chunkOrigin, RuleToHandlerMap &handlers ) const SIP_SKIP;
 
         /**
          * register individual features

src/3d/qgsrulebasedchunkloader_p.cpp

@@ -50,6 +50,12 @@ QgsRuleBasedChunkLoader::QgsRuleBasedChunkLoader( const QgsRuleBasedChunkLoaderF
 
   QgsVectorLayer *layer = mFactory->mLayer;
 
+  // only a subset of data to be queried
+  const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), mContext.origin() );
+  // origin for coordinates of the chunk - it is kind of arbitrary, but it should be
+  // picked so that the coordinates are relatively small to avoid numerical precision issues
+  QgsVector3D chunkOrigin( rect.center().x(), rect.center().y(), 0 );
+
   QgsExpressionContext exprContext( Qgs3DUtils::globalProjectLayerExpressionContext( layer ) );
   exprContext.setFields( layer->fields() );
   mContext.setExpressionContext( exprContext );
@@ -63,15 +69,12 @@ QgsRuleBasedChunkLoader::QgsRuleBasedChunkLoader( const QgsRuleBasedChunkLoaderF
   mRootRule->createHandlers( layer, mHandlers );
 
   QSet<QString> attributeNames;
-  mRootRule->prepare( mContext, attributeNames, mHandlers );
+  mRootRule->prepare( mContext, attributeNames, chunkOrigin, mHandlers );
 
   // build the feature request
   QgsFeatureRequest req;
   req.setDestinationCrs( mContext.crs(), mContext.transformContext() );
   req.setSubsetOfAttributes( attributeNames, layer->fields() );
-
-  // only a subset of data to be queried
-  const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), mContext.origin() );
   req.setFilterRect( rect );
 
   //

src/3d/qgstessellatedpolygongeometry.cpp

@@ -82,42 +82,6 @@ QgsTessellatedPolygonGeometry::QgsTessellatedPolygonGeometry( bool _withNormals,
   }
 }
 
-void QgsTessellatedPolygonGeometry::setPolygons( const QList<QgsPolygon *> &polygons, const QList<QgsFeatureId> &featureIds, const QgsPointXY &origin, float extrusionHeight, const QList<float> &extrusionHeightPerPolygon )
-{
-  Q_ASSERT( polygons.count() == featureIds.count() );
-  mTriangleIndexStartingIndices.reserve( polygons.count() );
-  mTriangleIndexFids.reserve( polygons.count() );
-
-  QgsTessellator tessellator( origin.x(), origin.y(), mWithNormals, mInvertNormals, mAddBackFaces, false, mAddTextureCoords );
-  for ( int i = 0; i < polygons.count(); ++i )
-  {
-    Q_ASSERT( tessellator.dataVerticesCount() % 3 == 0 );
-    const uint startingTriangleIndex = static_cast<uint>( tessellator.dataVerticesCount() / 3 );
-    mTriangleIndexStartingIndices.append( startingTriangleIndex );
-    mTriangleIndexFids.append( featureIds[i] );
-
-    QgsPolygon *polygon = polygons.at( i );
-    const float extr = extrusionHeightPerPolygon.isEmpty() ? extrusionHeight : extrusionHeightPerPolygon.at( i );
-    tessellator.addPolygon( *polygon, extr );
-  }
-  if ( !tessellator.error().isEmpty() )
-  {
-    QgsMessageLog::logMessage( tessellator.error(), QObject::tr( "3D" ) );
-  }
-
-  qDeleteAll( polygons );
-
-  const QByteArray data( ( const char * )tessellator.data().constData(), tessellator.data().count() * sizeof( float ) );
-  const int nVerts = data.count() / tessellator.stride();
-
-  mVertexBuffer->setData( data );
-  mPositionAttribute->setCount( nVerts );
-  if ( mNormalAttribute )
-    mNormalAttribute->setCount( nVerts );
-  if ( mAddTextureCoords )
-    mTextureCoordsAttribute->setCount( nVerts );
-}
-
 void QgsTessellatedPolygonGeometry::setData( const QByteArray &vertexBufferData, int vertexCount, const QVector<QgsFeatureId> &triangleIndexFids, const QVector<uint> &triangleIndexStartingIndices )
 {
   mTriangleIndexStartingIndices = triangleIndexStartingIndices;

src/3d/qgstessellatedpolygongeometry.h

@@ -91,9 +91,6 @@ class QgsTessellatedPolygonGeometry : public Qt3DCore::QGeometry
      */
     void setAddTextureCoords( bool add ) { mAddTextureCoords = add; }
 
-    //! Initializes vertex buffer from given polygons. Takes ownership of passed polygon geometries
-    void setPolygons( const QList<QgsPolygon *> &polygons, const QList<QgsFeatureId> &featureIds, const QgsPointXY &origin, float extrusionHeight, const QList<float> &extrusionHeightPerPolygon = QList<float>() );
-
     /**
      * Initializes vertex buffer (and other members) from data that were already tessellated.
      * This is an alternative to setPolygons() - this method does not do any expensive work in the body.

src/3d/qgsvectorlayerchunkloader_p.cpp

@@ -59,12 +59,18 @@ QgsVectorLayerChunkLoader::QgsVectorLayerChunkLoader( const QgsVectorLayerChunkL
   }
   mHandler.reset( handler );
 
+  // only a subset of data to be queried
+  const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), mRenderContext.origin() );
+  // origin for coordinates of the chunk - it is kind of arbitrary, but it should be
+  // picked so that the coordinates are relatively small to avoid numerical precision issues
+  QgsVector3D chunkOrigin( rect.center().x(), rect.center().y(), 0 );
+
   QgsExpressionContext exprContext( Qgs3DUtils::globalProjectLayerExpressionContext( layer ) );
   exprContext.setFields( layer->fields() );
   mRenderContext.setExpressionContext( exprContext );
 
   QSet<QString> attributeNames;
-  if ( !mHandler->prepare( mRenderContext, attributeNames ) )
+  if ( !mHandler->prepare( mRenderContext, attributeNames, chunkOrigin ) )
   {
     QgsDebugError( QStringLiteral( "Failed to prepare 3D feature handler!" ) );
     return;
@@ -76,9 +82,6 @@ QgsVectorLayerChunkLoader::QgsVectorLayerChunkLoader( const QgsVectorLayerChunkL
     QgsCoordinateTransform( layer->crs3D(), mRenderContext.crs(), mRenderContext.transformContext() )
   );
   req.setSubsetOfAttributes( attributeNames, layer->fields() );
-
-  // only a subset of data to be queried
-  const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), mRenderContext.origin() );
   req.setFilterRect( rect );
 
   //

src/3d/shaders/instanced.vert

@@ -7,9 +7,9 @@ in vec3 pos;
 out vec3 worldPosition;
 out vec3 worldNormal;
 
-uniform mat4 modelView;
-uniform mat3 modelViewNormal;
-uniform mat4 modelViewProjection;
+uniform mat4 modelMatrix;
+uniform mat3 modelNormalMatrix;
+uniform mat4 mvp;
 
 uniform mat4 inst;  // transform of individual object instance
 uniform mat4 instNormal;  // should be mat3 but Qt3D only supports mat4...
@@ -20,15 +20,26 @@ uniform mat4 instNormal;  // should be mat3 but Qt3D only supports mat4...
 
 void main()
 {
-    // TODO: i think this is not entirely correct: the translation by "pos" works
-    // like this only because we assume that "inst" matrix only does translation/scale/rotation
-    // which all keep "w" set to 1. correctly we should use translation matrix...
-    vec4 offsetPos = inst * vec4(vertexPosition, 1.0) + vec4(pos, 0.0);
+    // vertexPosition uses XZ plane as the base plane, with Y going upwards
+    // and the coordinates are local to the object
 
-    worldNormal = normalize(mat3(instNormal) * vertexNormal);
-    worldPosition = vec3(offsetPos);
+    // first let's apply user defined transform for each object (translation, rotation, scaling)
+    vec3 vertexPositionObject = vec3(inst * vec4(vertexPosition, 1.0));
+    vec3 vertexNormalObject = mat3(instNormal) * vertexNormal;
 
-    gl_Position = modelViewProjection * offsetPos;
+    // next let's flip axes, so we have XY plane as the base plane (like in map coordinates)
+    vertexPositionObject = vec3(vertexPositionObject.x, -vertexPositionObject.z, vertexPositionObject.y);
+    vertexNormalObject = vec3(vertexNormalObject.x, -vertexNormalObject.z, vertexNormalObject.y);
+
+    // add offset of the object relative to the chunk's origin
+    vec3 vertexPositionChunk = vertexPositionObject + pos;
+
+    // Transform position and normal to world space
+    worldPosition = vec3(modelMatrix * vec4(vertexPositionChunk, 1.0));
+    worldNormal = normalize(modelNormalMatrix * vertexNormalObject);
+
+    // Calculate vertex position in clip coordinates
+    gl_Position = mvp * vec4(vertexPositionChunk, 1.0);
 
 #ifdef CLIPPING
     setClipDistance(worldPosition);