QgsMeshTransformVerticesByExpression Class Reference

Transforms vertices of a mesh by expression. More...

#include <qgsmeshadvancedediting.h>

Inheritance diagram for QgsMeshTransformVerticesByExpression:

Public Member Functions
	QgsMeshTransformVerticesByExpression ()=default
bool	calculate (QgsMeshLayer *layer, QgsProject *project=nullptr)
	Calculates the transformed vertices of the mesh layer, returns false if this leads to topological or geometrical errors.
void	setExpressions (const QString &expressionX, const QString &expressionY, const QString &expressionZ)
	Sets the expressions for the coordinates transformation.
void	setZFromTerrain (bool enable)
	Sets if Z values for vertices should be obtained from project terrain, instead of expression.
QString	text () const override
	Returns a short text string describing what this advanced edit does. Default implementation return a void string.
QgsMeshVertex	transformedVertex (QgsMeshLayer *layer, int vertexIndex) const
	Returns the transformed vertex from its index vertexIndex for the mesh layer.
Public Member Functions inherited from QgsMeshAdvancedEditing
	QgsMeshAdvancedEditing ()
virtual	~QgsMeshAdvancedEditing ()
void	clear ()
	Removes all data provided to the editing or created by the editing.
virtual bool	isFinished () const
	Returns whether the advanced edit is finished, if not, this edit has to be applied again with QgsMeshEditor::advancedEdit() until is finished returns true.
QString	message () const
	Returns a message that can be provided by the advanced editing when applying is done.
void	setInputFaces (const QList< int > faceIndexes)
	Sets the input faces indexes that will be used for the editing.
void	setInputVertices (const QList< int > verticesIndexes)
	Sets the input vertices indexes that will be used for the editing.
Public Member Functions inherited from QgsTopologicalMesh::Changes
QVector< QgsMeshFace >	addedFaces () const
	Returns the face that are added with this changes.
QVector< QgsMeshVertex >	addedVertices () const
	Returns the added vertices with this changes.
QList< int >	changedCoordinatesVerticesIndexes () const
	Returns the indexes of vertices that have changed coordinates.
bool	isEmpty () const
	Returns whether changes are empty, that there is nothing to change.
QList< int >	nativeFacesIndexesGeometryChanged () const
	Returns a list of the native face indexes that have a geometry changed.
QList< QgsPointXY >	newVerticesXYValues () const
	Returns the new (X,Y) values of vertices that have changed their coordinates.
QList< double >	newVerticesZValues () const
	Returns the new Z values of vertices that have changed their coordinates.
QList< QgsPointXY >	oldVerticesXYValues () const
	Returns the old (X,Y) values of vertices that have changed their coordinates.
QList< int >	removedFaceIndexes () const
	Returns the indexes of the faces that are removed with this changes.
QVector< QgsMeshFace >	removedFaces () const
	Returns the faces that are removed with this changes.
QList< int >	verticesToRemoveIndexes () const
	Returns the indexes of vertices to remove.

Friends
class	TestQgsMeshEditor

Additional Inherited Members
Protected Member Functions inherited from QgsTopologicalMesh::Changes
void	clearChanges ()
	Clears all changes.
Protected Attributes inherited from QgsMeshAdvancedEditing
QList< int >	mInputFaces
QList< int >	mInputVertices
bool	mIsFinished = false
QString	mMessage
Protected Attributes inherited from QgsTopologicalMesh::Changes
int	mAddedFacesFirstIndex = 0
QList< int >	mChangeCoordinateVerticesIndexes
QList< int >	mFaceIndexesToRemove
QVector< FaceNeighbors >	mFacesNeighborhoodToAdd
QVector< FaceNeighbors >	mFacesNeighborhoodToRemove
QVector< QgsMeshFace >	mFacesToAdd
QVector< QgsMeshFace >	mFacesToRemove
QList< int >	mNativeFacesIndexesGeometryChanged
QList< std::array< int, 4 > >	mNeighborhoodChanges
QList< QgsPointXY >	mNewXYValues
QList< double >	mNewZValues
QList< QgsPointXY >	mOldXYValues
QList< double >	mOldZValues
QList< QgsMeshVertex >	mRemovedVertices
QVector< int >	mVertexToFaceToAdd
QVector< QgsMeshVertex >	mVerticesToAdd
QList< std::array< int, 3 > >	mVerticesToFaceChanges
QList< int >	mVerticesToFaceRemoved
QList< int >	mVerticesToRemoveIndexes

Detailed Description

Transforms vertices of a mesh by expression.

Each coordinates are associated with an expression that can be defined with function returning the current coordinates (see setExpressions()):

• $vertex_x
• $vertex_y
• $vertex_z

Example: Transposing a mesh and translate following axe X with a distance of 50 and increase the level of the mesh with an height of 80 when previous X coordinate is under 100 and de crease the level of 150 when X is under 100:

expressionX: "$vertex_y + 50" expressionY: "$vertex_x" expressionZ: "if( $vertex_x <= 100 , $vertex_z + 80 , $vertex_z - 150)"

Since

QGIS 3.22

Definition at line 162 of file qgsmeshadvancedediting.h.

Constructor & Destructor Documentation

QgsMeshTransformVerticesByExpression()

QgsMeshTransformVerticesByExpression::QgsMeshTransformVerticesByExpression ( )

default

Member Function Documentation

calculate()

bool QgsMeshTransformVerticesByExpression::calculate	(	QgsMeshLayer *	layer,
		QgsProject *	project = nullptr
	)

Calculates the transformed vertices of the mesh layer, returns false if this leads to topological or geometrical errors.

The mesh layer must be in edit mode.

Note

This method does not apply new vertices to the mesh layer but only stores the calculated transformation that can be applied later with QgsMeshEditor.advancedEdit()

Parameters

layer
project	QgsProject if it is necessary for the calculation ( for example with

See also

setZFromTerrain() )

Since

QGIS 3.44

Definition at line 615 of file qgsmeshadvancedediting.cpp.

setExpressions()

void QgsMeshTransformVerticesByExpression::setExpressions	(	const QString &	expressionX,
		const QString &	expressionY,
		const QString &	expressionZ
	)

Sets the expressions for the coordinates transformation.

Note

Expressions are optional for each coordinate, the coordinate will not be transformed if the string is void.

Definition at line 808 of file qgsmeshadvancedediting.cpp.

setZFromTerrain()

void QgsMeshTransformVerticesByExpression::setZFromTerrain

(

bool

enable

)

Sets if Z values for vertices should be obtained from project terrain, instead of expression.

Note

If enable is True, the Z value of the vertex will be obtained from the terrain of the project. The optional parameter project is necessary for function calculate (

See also

calculate() ).

Parameters

enable

Since

QGIS 3.44

Definition at line 848 of file qgsmeshadvancedediting.cpp.

text()

QString QgsMeshTransformVerticesByExpression::text ( ) const

overridevirtual

Returns a short text string describing what this advanced edit does. Default implementation return a void string.

Reimplemented from QgsMeshAdvancedEditing.

Definition at line 803 of file qgsmeshadvancedediting.cpp.

transformedVertex()

QgsMeshVertex QgsMeshTransformVerticesByExpression::transformedVertex	(	QgsMeshLayer *	layer,
		int	vertexIndex
	)		const

Returns the transformed vertex from its index vertexIndex for the mesh layer.

If layer is not the same than the one used to make the calculation, this will create an undefined behavior

Definition at line 824 of file qgsmeshadvancedediting.cpp.

Friends And Related Symbol Documentation

TestQgsMeshEditor

friend class TestQgsMeshEditor

friend

Definition at line 217 of file qgsmeshadvancedediting.h.

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The documentation for this class was generated from the following files:

• /build/qgis-3.43.0+git20250408+c67cf405802+99sid/src/core/mesh/qgsmeshadvancedediting.h
• /build/qgis-3.43.0+git20250408+c67cf405802+99sid/src/core/mesh/qgsmeshadvancedediting.cpp