QGIS API Documentation 3.27.0-Master (f261cc1f8b)
qgsmesh3dsymbol_p.cpp
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1/***************************************************************************
2 qgsmesh3dsymbol_p.cpp
3 ---------------------
4 Date : January 2019
5 Copyright : (C) 2019 by Peter Petrik
6 Email : zilolv at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#include "qgsmesh3dsymbol_p.h"
17
18#include "qgsmesh3dsymbol.h"
20#include "qgs3dmapsettings.h"
21#include "qgs3dutils.h"
22
23#include <Qt3DCore/QTransform>
24#include <Qt3DRender/QEffect>
25#include <Qt3DRender/QTechnique>
26#include <Qt3DRender/QCullFace>
27
28#include "qgsmultipolygon.h"
29#include "qgsmeshlayer.h"
30#include "qgstriangularmesh.h"
33
34static QgsExpressionContext _expressionContext3D()
35{
39 return ctx;
40}
41
43
44QgsMesh3DSymbolEntity::QgsMesh3DSymbolEntity( const Qgs3DMapSettings &map,
45 QgsMeshLayer *layer,
46 const QgsMesh3DSymbol &symbol,
47 Qt3DCore::QNode *parent )
48 : Qt3DCore::QEntity( parent )
49{
50 // build the default material
51 Qt3DRender::QMaterial *mat = material( symbol );
52
53 // build a transform function
54 Qt3DCore::QTransform *tform = new Qt3DCore::QTransform;
55 tform->setTranslation( QVector3D( 0, 0, 0 ) );
56
57 // build the entity
58 QgsMesh3DSymbolEntityNode *entity = new QgsMesh3DSymbolEntityNode( map, layer, symbol );
59 entity->findChild<Qt3DRender::QGeometryRenderer *>()->setObjectName( QStringLiteral( "main" ) ); // temporary measure to distinguish between "selected" and "main"
60 entity->addComponent( mat );
61 entity->addComponent( tform );
62 entity->setParent( this );
63}
64
65Qt3DRender::QMaterial *QgsMesh3DSymbolEntity::material( const QgsMesh3DSymbol &symbol ) const
66{
67 const QgsMaterialContext context;
68 Qt3DRender::QMaterial *material = symbol.material()->toMaterial( QgsMaterialSettingsRenderingTechnique::Triangles, context );
69
70 // front/back side culling
71 const auto techniques = material->effect()->techniques();
72 for ( auto tit = techniques.constBegin(); tit != techniques.constEnd(); ++tit )
73 {
74 auto renderPasses = ( *tit )->renderPasses();
75 for ( auto rpit = renderPasses.begin(); rpit != renderPasses.end(); ++rpit )
76 {
77 Qt3DRender::QCullFace *cullFace = new Qt3DRender::QCullFace;
78 cullFace->setMode( Qt3DRender::QCullFace::Back );
79 ( *rpit )->addRenderState( cullFace );
80 }
81 }
82 return material;
83}
84
85QgsMesh3DSymbolEntityNode::QgsMesh3DSymbolEntityNode( const Qgs3DMapSettings &map,
86 QgsMeshLayer *layer,
87 const QgsMesh3DSymbol &symbol,
88 Qt3DCore::QNode *parent ) : Qt3DCore::QEntity( parent )
89{
90 addComponent( renderer( map, symbol, layer ) );
91}
92
93Qt3DRender::QGeometryRenderer *QgsMesh3DSymbolEntityNode::renderer( const Qgs3DMapSettings &map,
94 const QgsMesh3DSymbol &symbol,
95 const QgsMeshLayer *layer )
96{
97 const QgsPointXY origin( map.origin().x(), map.origin().y() );
98 QList<QgsPolygon *> polygons;
99 QList<QgsFeatureId> fids;
100
101 const QgsExpressionContext ctx( _expressionContext3D() );
102 const QgsPropertyCollection &ddp = symbol.dataDefinedProperties();
103 const bool hasDDHeight = ddp.isActive( QgsAbstract3DSymbol::PropertyHeight );
104 float height = symbol.height();
105 if ( hasDDHeight )
106 {
107 height = static_cast<float>( ddp.valueAsDouble( QgsAbstract3DSymbol::PropertyHeight,
108 ctx,
109 static_cast<double>( height )
110 )
111 );
112 }
113
114 const QgsTriangularMesh *mesh = layer->triangularMesh();
115 if ( mesh )
116 {
117 const QVector<QgsMeshFace> &triangles = mesh->triangles();
118 const QVector<QgsMeshVertex> &vertices = mesh->vertices();
119 for ( int i = 0; i < triangles.size(); ++i )
120 {
121 const QgsMeshFace &triangle = triangles.at( i );
122 Q_ASSERT( triangle.size() == 3 );
123 std::unique_ptr< QgsPolygon > polygon = QgsMeshUtils::toPolygon( triangle, vertices );
124 Qgs3DUtils::clampAltitudes( polygon.get(),
125 symbol.altitudeClamping(),
127 height,
128 map );
129 polygons.append( polygon.release() );
130 fids.append( i );
131 }
132 }
133
134 // Polygons from mesh are already triangles, but
135 // call QgsTessellatedPolygonGeometry to
136 // use symbol settings for back faces, normals, etc
137
138 const QgsPhongTexturedMaterialSettings *texturedMaterialSettings = dynamic_cast< const QgsPhongTexturedMaterialSettings * >( symbol.material() );
139
140 mGeometry = new QgsTessellatedPolygonGeometry( true, false, symbol.addBackFaces(), texturedMaterialSettings ? texturedMaterialSettings->requiresTextureCoordinates() : false );
141 const QList<float> extrusionHeightPerPolygon;
142 mGeometry->setPolygons( polygons, fids, origin, 0.0, extrusionHeightPerPolygon );
143
144 Qt3DRender::QGeometryRenderer *renderer = new Qt3DRender::QGeometryRenderer;
145 renderer->setGeometry( mGeometry );
146
147 return renderer;
148}
@ Vertex
Clamp every vertex of feature.
QgsVector3D origin() const
Returns coordinates in map CRS at which 3D scene has origin (0,0,0)
static void clampAltitudes(QgsLineString *lineString, Qgis::AltitudeClamping altClamp, Qgis::AltitudeBinding altBind, const QgsPoint &centroid, float height, const Qgs3DMapSettings &map)
Clamps altitude of vertices of a linestring according to the settings.
Definition: qgs3dutils.cpp:351
@ PropertyHeight
Height (altitude)
QgsPropertyCollection & dataDefinedProperties()
Returns a reference to the symbol layer's property collection, used for data defined overrides.
virtual Qt3DRender::QMaterial * toMaterial(QgsMaterialSettingsRenderingTechnique technique, const QgsMaterialContext &context) const =0
Creates a new QMaterial object representing the material settings.
double valueAsDouble(int key, const QgsExpressionContext &context, double defaultValue=0.0, bool *ok=nullptr) const
Calculates the current value of the property with the specified key and interprets it as a double.
static QgsExpressionContextScope * projectScope(const QgsProject *project)
Creates a new scope which contains variables and functions relating to a QGIS project.
static QgsExpressionContextScope * globalScope()
Creates a new scope which contains variables and functions relating to the global QGIS context.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
QgsAbstractMaterialSettings * material() const
Returns material used for shading of the symbol.
Qgis::AltitudeClamping altitudeClamping() const
Returns method that determines altitude (whether to clamp to feature to terrain)
bool addBackFaces() const
Returns whether also triangles facing the other side will be created.
float height() const
Returns height (altitude) of the symbol (in map units)
Represents a mesh layer supporting display of data on structured or unstructured meshes.
Definition: qgsmeshlayer.h:99
QgsTriangularMesh * triangularMesh(double minimumTriangleSize=0) const
Returns triangular mesh (nullptr before rendering or calling to updateMesh).
bool requiresTextureCoordinates() const
Returns true if the material requires texture coordinates to be generated during triangulation....
A class to represent a 2D point.
Definition: qgspointxy.h:59
static QgsProject * instance()
Returns the QgsProject singleton instance.
Definition: qgsproject.cpp:480
A grouped map of multiple QgsProperty objects, each referenced by a integer key value.
bool isActive(int key) const override
Returns true if the collection contains an active property with the specified key.
Triangular/Derived Mesh is mesh with vertices in map coordinates.
const QVector< QgsMeshFace > & triangles() const
Returns triangles.
const QVector< QgsMeshVertex > & vertices() const
Returns vertices in map coordinate system.
double y() const
Returns Y coordinate.
Definition: qgsvector3d.h:51
double x() const
Returns X coordinate.
Definition: qgsvector3d.h:49
@ Triangles
Triangle based rendering (default)
CORE_EXPORT std::unique_ptr< QgsPolygon > toPolygon(const QgsMeshFace &face, const QVector< QgsMeshVertex > &vertices)
Returns face as polygon geometry, caller is responsible for delete.
QVector< int > QgsMeshFace
List of vertex indexes.