Further improve 3D Map View performance

src/3d/qgs3dmapscene.cpp

@@ -310,15 +310,7 @@ void Qgs3DMapScene::onCameraChanged()
   }
 
   updateScene( true );
-  bool changedCameraPlanes = updateCameraNearFarPlanes();
-
-  if ( changedCameraPlanes )
-  {
-    // repeat update of entities - because we have updated camera's near/far planes,
-    // the active nodes may have changed as well
-    updateScene( true );
-    updateCameraNearFarPlanes();
-  }
+  updateCameraNearFarPlanes();
 
   onShadowSettingsChanged();
 
@@ -342,6 +334,14 @@ void Qgs3DMapScene::updateScene( bool forceUpdate )
   sceneContext.cameraPos = camera->position();
   const QSize size = mEngine->size();
   sceneContext.screenSizePx = std::max( size.width(), size.height() ); // TODO: is this correct?
+
+  // Make our own projection matrix so that frustum culling done by the
+  // entities isn't dependent on the current near/far planes, which would then
+  // require multiple steps to stabilize.
+  QMatrix4x4 projMatrix;
+  projMatrix.setToIdentity();
+  // Just use some high values for the far plane so we don't have to custom-make the matrix.
+  projMatrix.perspective( camera->fieldOfView(), camera->aspectRatio(), 1, 10'000'000 );
   sceneContext.viewProjectionMatrix = camera->projectionMatrix() * camera->viewMatrix();
 
 

src/3d/qgsvirtualpointcloudentity_p.cpp

@@ -130,9 +130,18 @@ void QgsVirtualPointCloudEntity::handleSceneUpdate( const SceneContext &sceneCon
   const QVector<QgsPointCloudSubIndex> subIndexes = provider()->subIndexes();
   for ( int i = 0; i < subIndexes.size(); ++i )
   {
+    // If the chunked entity needs an update, do it even if it's occluded,
+    // since otherwise we'd return needsUpdate() == true until it comes into
+    // view again.
+    bool needsUpdate = mChunkedEntitiesMap.contains( i ) && mChunkedEntitiesMap[i]->needsUpdate();
+
     const QgsBox3D &box3D = mBboxes.at( i );
 
-    if ( box3D.isEmpty() )
+    if ( !needsUpdate && box3D.isEmpty() )
+      continue;
+
+    QgsAABB aabb = QgsAABB::fromBox3D( box3D, mBboxesEntity->vertexDataOrigin() );
+    if ( !needsUpdate && Qgs3DUtils::isCullable( aabb, sceneContext.viewProjectionMatrix ) )
       continue;
 
     // magic number 256 is the common span value for a COPC root node