qgsmesh3dmaterial: Add support for gl_ClipDistance

This is achieved with two changes:
1. define the plane equation as uniform with the
`Qgs3DUtils::addBoundingBoxParametersToEffect` call
2. include `clipplane.inc` file in the vertex shader file and call
setClipDistance()

With these changes, the planes defined in the framegraph are used.

src/3d/mesh/qgsmesh3dentity_p.cpp

@@ -67,7 +67,7 @@ void QgsMeshDataset3DEntity::applyMaterial()
     if ( datasetGroupIndex >= 0 )
       mSymbol->setColorRampShader( rendererSettings.scalarSettings( datasetGroupIndex ).colorRampShader() );
   }
-  QgsMesh3DMaterial *material = new QgsMesh3DMaterial( layer(), mMapSettings.temporalRange(), mMapSettings.origin(), mSymbol.get(), QgsMesh3DMaterial::ScalarDataSet );
+  QgsMesh3DMaterial *material = new QgsMesh3DMaterial( layer(), mMapSettings, mSymbol.get(), QgsMesh3DMaterial::ScalarDataSet );
   addComponent( material );
 }
 
@@ -96,8 +96,8 @@ void QgsMesh3DTerrainTileEntity::buildGeometry()
 void QgsMesh3DTerrainTileEntity::applyMaterial()
 {
   QgsMesh3DMaterial *material = new QgsMesh3DMaterial(
-    nullptr, QgsDateTimeRange(),
-    mMapSettings.origin(),
+    nullptr,
+    mMapSettings,
     mSymbol.get(),
     QgsMesh3DMaterial::ZValue );
   addComponent( material );

src/3d/mesh/qgsmesh3dmaterial_p.cpp

@@ -16,6 +16,7 @@
  ***************************************************************************/
 
 #include "qgsmesh3dmaterial_p.h"
+#include "qgs3dmapsettings.h"
 
 #include <Qt3DRender/QEffect>
 #include <Qt3DRender/QGraphicsApiFilter>
@@ -110,21 +111,22 @@ class ArrowsTextureGenerator: public Qt3DRender::QTextureImageDataGenerator
 
 
 QgsMesh3DMaterial::QgsMesh3DMaterial( QgsMeshLayer *layer,
-                                      const QgsDateTimeRange &timeRange,
-                                      const QgsVector3D &origin,
+                                      const Qgs3DMapSettings &mapSettings,
                                       const QgsMesh3DSymbol *symbol,
                                       MagnitudeType magnitudeType )
   : mSymbol( symbol->clone() )
   , mMagnitudeType( magnitudeType )
-  , mOrigin( origin )
+  , mOrigin( mapSettings.origin() )
 {
   Qt3DRender::QEffect *eff = new Qt3DRender::QEffect( this );
 
   configure();
 
   // this method has to be called even if there isn't arrows (terrain) because it configures the parameter of shaders
   // If all the parameters ("uniform" in shaders) are not defined in QGIS, the shaders sometimes don't work (depends on hardware?)
-  configureArrows( layer, timeRange );
+  configureArrows( layer, mapSettings.temporalRange() );
+
+  Qgs3DUtils::addBoundingBoxParametersToEffect( eff, mapSettings );
 
   eff->addTechnique( mTechnique );
   setEffect( eff );

src/3d/mesh/qgsmesh3dmaterial_p.h

@@ -24,6 +24,7 @@
 #include <Qt3DRender/QTechnique>
 #include <Qt3DRender/QAbstractTextureImage>
 
+#include "qgs3dmapsettings.h"
 #include "qgsmesh3dsymbol.h"
 #include "qgsvector3d.h"
 
@@ -41,6 +42,7 @@
 #define SIP_NO_FILE
 
 class QgsMeshLayer;
+class Qgs3DMapSettings;
 
 /**
  * \ingroup 3d
@@ -71,8 +73,7 @@ class QgsMesh3DMaterial : public Qt3DRender::QMaterial
 
     //! Constructor
     QgsMesh3DMaterial( QgsMeshLayer *layer,
-                       const QgsDateTimeRange &timeRange,
-                       const QgsVector3D &origin,
+                       const Qgs3DMapSettings &mapSettings,
                        const QgsMesh3DSymbol *symbol,
                        MagnitudeType magnitudeType = ZValue );
 

src/3d/shaders/mesh/mesh.vert

@@ -16,6 +16,8 @@ out MeshVertex {
     float magnitude;
 } vs_out;
 
+#pragma include ../clipplane.inc
+
 void main()
 {
     gl_Position = mvp * vec4( vertexPosition, 1.0 );
@@ -28,4 +30,6 @@ void main()
         vs_out.magnitude=scalarMagnitude;
     else
         vs_out.magnitude=worldPosition.y;
+
+    setClipDistance(worldPosition);
 }