initial implementation of the scene exporter class

qgis · Jun 28, 2020 · 273b8f3 · 273b8f3
1 parent 9b8e983
commit 273b8f3
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diff --git a/src/3d/CMakeLists.txt b/src/3d/CMakeLists.txt
@@ -68,6 +68,7 @@ SET(QGIS_3D_SRCS
   mesh/qgsmesh3dentity_p.cpp
   mesh/qgsmesh3dmaterial_p.cpp
   mesh/qgsmeshterraingenerator.cpp
+  qgs3dsceneexporter.cpp
 
 )
 
@@ -110,6 +111,7 @@ SET(QGIS_3D_HDRS
   chunks/qgschunkloader_p.h
   chunks/qgschunkqueuejob_p.h
   mesh/qgsmeshterraingenerator.h
+  qgs3dsceneexporter.h
 )
 
 SET(QGIS_3D_PRIVATE_HDRS

diff --git a/src/3d/qgs3dmapscene.cpp b/src/3d/qgs3dmapscene.cpp
@@ -57,6 +57,8 @@
 #include "qgsmaplayertemporalproperties.h"
 
 #include "qgslinematerial_p.h"
+#include "qgs3dsceneexporter.h"
+#include "qgsabstract3drenderer.h"
 
 Qgs3DMapScene::Qgs3DMapScene( const Qgs3DMapSettings &map, QgsAbstract3DEngine *engine )
   : mMap( map )
@@ -763,3 +765,15 @@ void Qgs3DMapScene::updateSceneState()
 
   setSceneState( Ready );
 }
+
+void Qgs3DMapScene::exportScene(const QString& sceneName, const QString& sceneDir) {
+  Qgs3DSceneExporter exporter;
+
+  for ( QgsMapLayer * layer : mLayerEntities.keys() ) {
+    exporter.parseEntity(mLayerEntities[layer]);
+  }
+  QString filePath = sceneDir;
+  if (!filePath.endsWith('/')) filePath.push_back('/');
+  filePath += sceneName + ".obj";
+  exporter.saveToFile(filePath);
+}
diff --git a/src/3d/qgs3dmapscene.h b/src/3d/qgs3dmapscene.h
@@ -102,6 +102,7 @@ class _3D_EXPORT Qgs3DMapScene : public Qt3DCore::QEntity
      */
     float worldSpaceError( float epsilon, float distance );
 
+    void exportScene(const QString& sceneName, const QString& sceneDir);
   signals:
     //! Emitted when the current terrain entity is replaced by a new one
     void terrainEntityChanged();

diff --git a/src/3d/qgs3dsceneexporter.cpp b/src/3d/qgs3dsceneexporter.cpp
@@ -0,0 +1,111 @@
+#include "qgs3dsceneexporter.h"
+
+#include <QDebug>
+#include <QVector>
+#include <Qt3DCore/QEntity>
+#include <Qt3DCore/QComponent>
+#include <Qt3DCore/QNode>
+#include <Qt3DRender/QGeometry>
+#include <Qt3DRender/QAttribute>
+#include <Qt3DRender/QBuffer>
+#include <Qt3DRender/QGeometryRenderer>
+#include <qgstessellatedpolygongeometry.h>
+#include <qgs3dmapscene.h>
+#include <QByteArray>
+#include <QFile>
+#include <QTextStream>
+#include <QtMath>
+
+Qgs3DSceneExporter::Qgs3DSceneExporter( )
+  : mVertices(QVector<float>())
+{
+
+}
+
+
+void Qgs3DSceneExporter::parseEntity(Qt3DCore::QEntity* entity) {
+  if (entity == nullptr) return;
+  for (Qt3DCore::QComponent *c : entity->components()) {
+    Qt3DRender::QGeometryRenderer* comp = qobject_cast<Qt3DRender::QGeometryRenderer*>(c);
+    if (comp == nullptr) continue;
+    Qt3DRender::QGeometry* geom = comp->geometry();
+    QgsTessellatedPolygonGeometry* polygonGeometry = qobject_cast<QgsTessellatedPolygonGeometry*>(geom);
+    if (geom == nullptr) continue;
+    if (polygonGeometry != nullptr) processGeometry(polygonGeometry);
+//    for (Qt3DRender::QAttribute* attribute : geom->attributes()) {
+//      processAttribute(attribute);
+//    }
+  }
+  for (QObject* child : entity->children()) {
+    Qt3DCore::QEntity* childEntity = qobject_cast<Qt3DCore::QEntity*>( child );
+    if (childEntity != nullptr) parseEntity(childEntity);
+  }
+}
+
+void Qgs3DSceneExporter::processAttribute(Qt3DRender::QAttribute* attribute) {
+  qDebug() << __PRETTY_FUNCTION__;
+  Qt3DRender::QBuffer* buffer = attribute->buffer();
+  QByteArray bufferData = buffer->data();
+  uint bytesOffset = attribute->byteOffset();
+  uint bytesStride = attribute->byteStride();
+  uint verticesCount = attribute->count();
+  uint vertexSize = attribute->vertexSize();
+
+  QDataStream stream(bufferData);
+
+  for (int offset = bytesOffset; offset < vertexSize * verticesCount * bytesStride; offset += bytesStride) {
+    QVector<float> verticeData;
+    for (int i = 0; i < vertexSize; ++i) {
+      float v;
+      stream >> v;
+      if (qIsInf(v)) break;
+      verticeData.push_back(v);
+    }
+    if (verticeData.size() == vertexSize) {
+      mVertices.append(verticeData);
+      qDebug() << "v" << verticeData[0] << verticeData[1] << verticeData[2];
+    }
+  }
+}
+
+void Qgs3DSceneExporter::saveToFile(const QString& filePath) {
+  QFile file(filePath);
+  if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
+      return;
+
+  qDebug() << filePath;
+  QTextStream out(&file);
+
+  // Construct vertices
+  for (int i = 0; i < mVertices.size(); i += 3) {
+    out << "v " << mVertices[i] << " " << mVertices[i + 1] << " " << mVertices[i + 2] << "\n";
+//    qDebug() << "v " << mVertices[i] << " " << mVertices[i + 1] << " " << mVertices[i + 2] << "\n";
+
+  }
+  // Construct faces
+  for (int i = 0; i < mVertices.size() / 9; ++i) {
+    out << "f " << 3 * i + 1 << " " << 3 * i + 2 << " " << 3 * i + 3 << "\n";
+//    qDebug() << "f " << 3 * i << " " << 3 * i + 1 << " " << 3 * i + 2 << "\n";
+  }
+}
+
+void Qgs3DSceneExporter::processGeometry(QgsTessellatedPolygonGeometry* geom) {
+  QByteArray data = geom->mVertexBuffer->data();
+  Qt3DRender::QAttribute* attribute = geom->mPositionAttribute;
+  uint bytesOffset = attribute->byteOffset();
+  uint bytesStride = attribute->byteStride();
+  uint verticesCount = attribute->count();
+  uint vertexSize = attribute->vertexSize();
+
+  QVector<float> floatData;
+  QDataStream dataStream(data);
+  while (!dataStream.atEnd()) {
+    float f;
+    dataStream >> f;
+    floatData.push_back(f);
+  }
+
+  for (int i = 0; i < floatData.size(); i += bytesStride / sizeof(float)) {
+    mVertices << floatData[i] << floatData[i + 1] << floatData[i + 2];
+  }
+}
diff --git a/src/3d/qgs3dsceneexporter.h b/src/3d/qgs3dsceneexporter.h
@@ -0,0 +1,26 @@
+#ifndef QGS3DSCENEEXPORTER_H
+#define QGS3DSCENEEXPORTER_H
+
+#include <Qt3DCore/QEntity>
+#include <Qt3DRender/QGeometry>
+#include <Qt3DRender/QAttribute>
+
+class QgsTessellatedPolygonGeometry;
+class Qgs3DMapSettings;
+
+class Qgs3DSceneExporter
+{
+
+public:
+  Qgs3DSceneExporter( );
+
+  void parseEntity(Qt3DCore::QEntity* entity);
+  void saveToFile(const QString& filePath);
+private:
+  void processAttribute(Qt3DRender::QAttribute* attribute);
+  void processGeometry(QgsTessellatedPolygonGeometry* geom);
+private:
+  QVector<float> mVertices;
+};
+
+#endif // QGS3DSCENEEXPORTER_H
diff --git a/src/3d/qgstessellatedpolygongeometry.h b/src/3d/qgstessellatedpolygongeometry.h
@@ -21,6 +21,8 @@
 
 #include <Qt3DRender/QGeometry>
 
+class Qgs3DSceneExporter;
+
 namespace Qt3DRender
 {
   class QBuffer;
@@ -79,12 +81,15 @@ class QgsTessellatedPolygonGeometry : public Qt3DRender::QGeometry
      */
     QgsFeatureId triangleIndexToFeatureId( uint triangleIndex ) const;
 
+    friend class Qgs3DSceneExporter;
   private:
 
     Qt3DRender::QAttribute *mPositionAttribute = nullptr;
     Qt3DRender::QAttribute *mNormalAttribute = nullptr;
     Qt3DRender::QBuffer *mVertexBuffer = nullptr;
 
+    QVector<float> mVertexData;
+
     QVector<QgsFeatureId> mTriangleIndexFids;
     QVector<uint> mTriangleIndexStartingIndices;
 

diff --git a/src/app/3d/qgs3dmapcanvasdockwidget.cpp b/src/app/3d/qgs3dmapcanvasdockwidget.cpp
@@ -44,6 +44,8 @@
 #include "qgs3dmaptoolmeasureline.h"
 #include "qgs3dutils.h"
 
+#include "qgs3dsceneexporter.h"
+#include "qgsabstract3drenderer.h"
 
 
 Qgs3DMapCanvasDockWidget::Qgs3DMapCanvasDockWidget( QWidget *parent )
@@ -99,6 +101,9 @@ Qgs3DMapCanvasDockWidget::Qgs3DMapCanvasDockWidget( QWidget *parent )
   toolBar->addAction( QgsApplication::getThemeIcon( QStringLiteral( "mActionSaveMapAsImage.svg" ) ),
                       tr( "Save as Image…" ), this, &Qgs3DMapCanvasDockWidget::saveAsImage );
 
+  toolBar->addAction( QIcon( QgsApplication::iconPath( "mActionSaveMapAsImage.svg" ) ),
+      tr( "Export 3D Scene" ), this, &Qgs3DMapCanvasDockWidget::exportScene );
+
   toolBar->addSeparator();
 
   // Map Theme Menu
@@ -170,6 +175,17 @@ void Qgs3DMapCanvasDockWidget::saveAsImage()
   }
 }
 
+
+void Qgs3DMapCanvasDockWidget::exportScene()
+{
+
+  QgsSettings settings;  // where we keep last used filter in persistent state
+  QString initialPath = settings.value( QStringLiteral( "UI/lastExportAsDir" ), QDir::homePath() ).toString();
+  QString outputDir = QFileDialog::getExistingDirectory(this, QString("Export scane"), initialPath);
+
+  mCanvas->scene()->exportScene("scene", outputDir);
+}
+
 void Qgs3DMapCanvasDockWidget::toggleAnimations()
 {
   if ( mAnimationWidget->isVisible() )

diff --git a/src/app/3d/qgs3dmapcanvasdockwidget.h b/src/app/3d/qgs3dmapcanvasdockwidget.h
@@ -59,6 +59,7 @@ class APP_EXPORT Qgs3DMapCanvasDockWidget : public QgsDockWidget
     void cameraControl();
     void identify();
     void measureLine();
+    void exportScene();
     void toggleNavigationWidget( bool visibility );
 
     void onMainCanvasLayersChanged();