Represents a defined area within a triangulation. More...

#include <Zone2.h>

Public Member Functions
Zone2 *	convertToBoundedZone ()
	Convert a zone to a bounded zone. More...

Zone2 *	createOffsetZone (Fade_2D *pFade, double offset, double mergeAngleDeg=10, double angleStep=20.0) const
	Creates an offset zone. More...

void	exportZone (FadeExport &fadeExport, bool bWithCustomIndices) const
	Export triangles from a zone. More...

double	getArea25D () const
	Get 2.5D Area. More...

double	getArea2D () const
	Get 2D Area. More...

void	getBorderEdges (std::vector< Edge2 > &vBorderEdgesOut) const
	Get border edges. More...

void	getBoundarySegments (std::vector< Segment2 > &vSegments) const
	Get the boundaries as segments. More...

Bbox2	getBoundingBox () const
	Compute the bounding box.

void	getComponentPolygons (std::vector< CompPolygon > &vCompPolygons) const
	Get connected components. More...

ConstraintGraph2 *	getConstraintGraph () const
	Get the associated constraint. More...

void	getConstraintGraphs (std::vector< ConstraintGraph2 * > &vConstraintGraphs_) const
	Get the associated constraint graphs.

double	getMedianEdgeLength25D ()
	Get the median 2.5D edge length. More...

double	getMedianEdgeLength2D ()
	Get the median 2D edge length. More...

ConstraintSegment2 *	getNearbyBoundaryConstraint (Point2 &p, double tolerance)
	Locates the nearest boundary `ConstraintSegment2` of the Zone2. More...

size_t	getNumberOfTriangles () const
	Get the number of triangles. More...

void	getOffsetBoundary (double offset, std::vector< Segment2 > &vOffsetBoundary, double mergeAngleDeg=10.0, double angleStepDeg=20.0) const
	Get the offset boundary of a shape. More...

void	getTriangles (std::vector< Triangle2 * > &vTriangles) const
	Get the triangles of the zone. More...

void	getVertices (std::vector< Point2 * > &vVertices_) const
	Get the vertices of the zone.

ZoneLocation	getZoneLocation () const
	Get the zone location. More...

bool	hasOn (const Point2 &p)
	Checks if a point lies on the zone. More...

bool	hasOnBoundary (const Point2 &p)
	Checks if a point lies on the boundary of the zone. More...

Triangle2 *	locate (const Point2 &p)
	Locates the triangle containing the given point within the zone. More...

Zone2 *	morphClose (Fade_2D *pFade, double offset, double mergeAngleDeg=10.0, double angleStep=20.0) const
	Morphological closing to bridge small gaps in the Zone2. More...

Zone2 *	morphOpen (Fade_2D *pFade, double offset, double mergeAngleDeg=10.0, double angleStep=20.0) const
	Morphological opening to remove small details. More...

size_t	numberOfConstraintGraphs () const
	Get the number of ConstraintGraph2 objects. More...

bool	save (const char *filename)
	Save the zone. More...

bool	save (std::ostream &stream)
	Save the zone. More...

bool	shiftToZone (const Point2 &q, double tolerance, Point2 &result)
	Finds a point close to the query that lies inside the zone. More...

void	show (const char *filename, bool bShowFull, bool bWithConstraints) const
	Postscript- and PDF-visualization. More...

void	show (const char *filename, const Colorname &zoneFillColor=CTRANSPARENT, const Colorname &zoneEdgeColor=CBLACK, const Colorname &nonZoneFillColor=CTRANSPARENT, const Colorname &nonZoneEdgeColor=CTRANSPARENT, const Colorname &constraintEdgeColor=CTRANSPARENT) const
	Postscript- and PDF visualization. More...

void	show (Visualizer2 *pVisualizer, bool bShowFull, bool bWithConstraints) const
	Postscript- and PDF-visualization. More...

void	show (Visualizer2 *pVisualizer, const Colorname &zoneFillColor=CTRANSPARENT, const Colorname &zoneEdgeColor=CBLACK, const Colorname &nonZoneFillColor=CTRANSPARENT, const Colorname &nonZoneEdgeColor=CTRANSPARENT, const Colorname &constraintEdgeColor=CTRANSPARENT) const
	Postscript- and PDF visualization. More...

void	showGeomview (const char filename, const char color) const
	Geomview visualization. More...

void	showGeomview (Visualizer3 pVis, const char color) const
	Geomview visualization. More...

void	showVtk (const char *filename, VtkColor zoneColor, VtkColor nonZoneColor=VTK_TRANSPARENT, VtkColor constraintColor=VTK_TRANSPARENT) const
	VTK visualization. More...

void	showVtk (VtkWriter *pVtk, VtkColor zoneColor, VtkColor nonZoneColor=VTK_TRANSPARENT, VtkColor constraintColor=VTK_TRANSPARENT) const
	VTK visualization. More...

void	slopeValleyRidgeOptimization (OptimizationMode om=OPTMODE_BETTER)
	Optimize Slopes, Valleys, and Ridges. More...

void	smoothing (int numIterations=2, bool bWithXY=true)
	Smoothing. More...

void	smoothing2 (int numIterations, bool bWithXY, bool bWithConstraintZ)
	Smooths the vertices of the zone. More...

void	statistics (const char *s) const
	Prints statistics. More...

void	subscribe (MsgType msgType, MsgBase *pMsg)
	Registers a message receiver. More...

void	unifyGrid (double tolerance)
	Unify Grid. More...

void	unsubscribe (MsgType msgType, MsgBase *pMsg)
	Unregisters a message receiver. More...

void	writeObj (const char *filename) const
	Write the Zone2 to an .obj file. More...

bool	writePly (const char *filename, bool bASCII=false) const
	Write the Zone2 to a *.ply file. More...

bool	writePly (std::ostream &os, bool bASCII=false) const
	Write the Zone2 to a *.ply file. More...

Protected Member Functions
Zone2 &	operator= (const Zone2 &)

Friends
CLASS_DECLSPEC friend Zone2 *	peelOffIf (Zone2 pZone, bool bAvoidSplit, PeelPredicateTS pPredicate)
	Peel off undesired border triangles. More...

CLASS_DECLSPEC friend Zone2 *	peelOffIf (Zone2 pZone, UserPredicateT pPredicate, bool bVerbose)
	Peel off undesired border triangles (deprecated) More...

CLASS_DECLSPEC friend Zone2 *	zoneDifference (Zone2 pZone0, Zone2 pZone1)
	Computes the difference between two Zone2 objects. More...

CLASS_DECLSPEC friend Zone2 *	zoneIntersection (Zone2 pZone0, Zone2 pZone1)
	Computes the intersection of two Zone2 objects. More...

CLASS_DECLSPEC friend Zone2 *	zoneSymmetricDifference (Zone2 pZone0, Zone2 pZone1)
	Computes the symmetric difference between two Zone2 objects. More...

CLASS_DECLSPEC friend Zone2 *	zoneUnion (Zone2 pZone0, Zone2 pZone1)
	Computes the union of two Zone2 objects. More...

Detailed Description

A Zone2 object represents a defined area within a triangulation.

A Zone2 is a defined area within a triangulation

See also: http://www.geom.at/example4-zones-defined-areas-in-triangulations/ for examples of how to create and use Zone2 objects.; http://www.geom.at/boolean-operations/ for a demonstration of boolean operations on zones.

Member Function Documentation

◆ convertToBoundedZone()

Zone2* GEOM_FADE25D::Zone2::convertToBoundedZone ( )

This method creates a bounded zone from a possibly unbounded one.

Algorithms like refine() and refineAdvanced() require a Zone2 object as input that is bounded by constraint edges. This is always the case for zones with zoneLocation ZL_INSIDE, but other types of zones may be unbounded.

Returns: A pointer to a new Zone2 object with zoneLocation ZL_RESULT_BOUNDED or a pointer to the present Zone2 if this->getZoneLocation() returns ZL_INSIDE.

◆ createOffsetZone()

Zone2* GEOM_FADE25D::Zone2::createOffsetZone	(	Fade_2D *	pFade,
		double	offset,
		double	mergeAngleDeg = `10`,
		double	angleStep = `20.0`
	)		const

Creates a positive or negative offset zone based on the current Zone2 and stores the result in a new Fade_2D object.

A Zone2 and a positive offset of it

Parameters

[in]	pFade	An empty `Fade_2D` object where the result zone will be created.
[in]	offset	The positive or negative offset distance.
[in]	mergeAngleDeg	is used as an angle threshold (in degrees) to merge small circular arcs in the offset shape into a single point. Default: 10.0, valid range: (>0,...,135)
[in]	angleStep	Specifies the angle interval (in degrees) at which circular arcs in the offset shape are sampled using line segments. Default: 20.0, valid range: (>0,...,135)

Returns: A pointer to a new Zone2 object, created within pFade or NULL if the result is empty, which may be the case if a large negative offset value is used. Be sure to check this case before proceeding.

◆ exportZone()

void GEOM_FADE25D::Zone2::exportZone	(	FadeExport &	fadeExport,
		bool	bWithCustomIndices
	)		const

Exports the Zone2 to a FadeExport struct.

Parameters

fadeExport	is a simple struct that will be filled with data
bWithCustomIndices	determines whether the custom indices of the points are also stored

See also: https://www.geom.at/triangulation-export/ This article explains the FadeExport struct in detail.

◆ getArea25D()

double GEOM_FADE25D::Zone2::getArea25D ( ) const

This method computes and returns the 2.5D area of the Zone2.

Returns: The 2.5D area of the Zone2.

◆ getArea2D()

double GEOM_FADE25D::Zone2::getArea2D ( ) const

This method computes and returns the 2D area of the Zone2, ignoring its elevation (the z-coordinate).

Returns: The 2D area of the Zone2.

◆ getBorderEdges()

void GEOM_FADE25D::Zone2::getBorderEdges ( std::vector< Edge2 > & vBorderEdgesOut ) const

Returns the boundaries of the Zone2.

Parameters

[out] vBorderEdgesOut A vector of Edge2 objects that will hold the counterclockwise oriented border edges of the Zone2 in arbitrary order.

◆ getBoundarySegments()

void GEOM_FADE25D::Zone2::getBoundarySegments ( std::vector< Segment2 > & vSegments ) const

Returns the boundaries of the Zone2 as Segment2 objects.

Parameters

[out] vSegments A vector of Segment2 objects that will hold the counterclockwise oriented border segments of the Zone2 in arbitrary order.

◆ getComponentPolygons()

void GEOM_FADE25D::Zone2::getComponentPolygons ( std::vector< CompPolygon > & vCompPolygons ) const

This method finds connected components of the Zone2. For each connected component, it returns a CompPolygon struct consisting of Triangle2 pointers of that component, the outer boundary polygon, and any hole polygons within the component, represented as Edge2 vectors.

Parameters

[out] vCompPolygons A vector that will hold the CompPolygon structs for each connected component.

Note: Edge2 objects consist of a Triangle2 and an index, and are always oriented counterclockwise around the associated Triangle2. As a result, the outer boundary polygon of a component is always oriented counterclockwise, while the hole polygons are oriented clockwise.

◆ getConstraintGraph()

ConstraintGraph2* GEOM_FADE25D::Zone2::getConstraintGraph ( ) const

Retrieves the associated ConstraintGraph2, if any.

Returns: A pointer to the ConstraintGraph2 object defining the Zone2, or NULL if no ConstraintGraph2 is associated.

◆ getMedianEdgeLength25D()

double GEOM_FADE25D::Zone2::getMedianEdgeLength25D ( )

Computes the median 2.5D edge length of all edges in the current zone.

Returns: The median 2.5D edge length of all edges in the zone.

◆ getMedianEdgeLength2D()

double GEOM_FADE25D::Zone2::getMedianEdgeLength2D ( )

Computes the median edge length of all edges in the current zone in 2D. This method considers the projection of the edges onto the XY plane, ignoring the z-coordinate. To compute the 2.5D median edge length, use getMedianEdgeLength25D().

Returns: The median 2D edge length of all edges in the zone.

◆ getNearbyBoundaryConstraint()

ConstraintSegment2* GEOM_FADE25D::Zone2::getNearbyBoundaryConstraint	(	Point2 &	p,
		double	tolerance
	)

This method locates the nearest ConstraintSegment2 on the boundary of the current Zone2 within the specified distance, but only if the point p has an orthogonal projection onto this ConstraintSegment2.

The red query point has an orthogonal projection onto the boundary, while the blue one does not.

Parameters

p	The point from which the search is initiated.
tolerance	The maximum allowed 2D distance between the point `p` and the `ConstraintSegment2`.

Returns: A pointer to the closest alive ConstraintSegment2 within the tolerance distance, where p has an orthogonal projection, or NULL if no such ConstraintSegment2 is found.

Note: The first call to any of the following methods initializes a search structure. For zones not of type ZL_INSIDE, ZL_BOUNDED, or ZL_GLOBAL, constraint edges are inserted around the zone.

◆ getNumberOfTriangles()

size_t GEOM_FADE25D::Zone2::getNumberOfTriangles ( ) const

This method computes and returns the number of triangles in the Zone2.

Returns: The number of triangles.

◆ getOffsetBoundary()

void GEOM_FADE25D::Zone2::getOffsetBoundary	(	double	offset,
		std::vector< Segment2 > &	vOffsetBoundary,
		double	mergeAngleDeg = `10.0`,
		double	angleStepDeg = `20.0`
	)		const

This function computes an offset boundary of a Zone2. The result is returned as a vector of counterclockwise-oriented Segment2 objects.

The positive offset boundary of a Zone2

Parameters

[in]	offset	The positive or negative offset distance.
[out]	vOffsetBoundary	A vector that will contain the output segments, in arbitrary order, oriented counterclockwise around the resulting shape.
[in]	mergeAngleDeg	The angle threshold (in degrees) used to merge circular arcs in the offset boundary. Arcs with an angle less than this value are collapsed to a single point. Default: 10.0, valid range: greater than 0 and up to 135.
[in]	angleStepDeg	Specifies the angle interval (in degrees) at which circular arcs are sampled using line segments. Default: 20.0, valid range: greater than 0 and up to 135.

See also: https://www.geom.at/offset-polygon-example/ This article contains examples on polygon offsets.

◆ getTriangles()

void GEOM_FADE25D::Zone2::getTriangles ( std::vector< Triangle2 * > & vTriangles ) const

This method retrieves the triangles of the zone.

Parameters

[out] vTriangles A vector of Triangle2 pointers that will be populated with the triangles of the present Zone2.

◆ getZoneLocation()

ZoneLocation GEOM_FADE25D::Zone2::getZoneLocation ( ) const

This method is used to retrieve the ZoneLocation value of the present Zone2.

Returns: The ZoneLocation value.

◆ hasOn()

bool GEOM_FADE25D::Zone2::hasOn ( const Point2 & p )

This method checks if the query point p lies on the Zone2 or its boundary.

Parameters

p	The point to check.

Returns: true if the point is on the Zone2 or its boundary, false otherwise.

The first call to this method initializes a search structure. If boundary edges of the Zone2 are not constraint edges yet, constraint edges are created.

◆ hasOnBoundary()

bool GEOM_FADE25D::Zone2::hasOnBoundary ( const Point2 & p )

This method checks if the query point p lies exactly on the boundary of the present Zone2.

Parameters

p	The point to check.

Returns: true if the point is on the zone's boundary, false otherwise.

The first call to this method initializes a search structure. If boundary edges of the Zone2 are not constraint edges yet, constraint edges are created.

◆ locate()

Triangle2* GEOM_FADE25D::Zone2::locate ( const Point2 & p )

Locates the triangle containing the query point within the Zone2.

Parameters

p	The point to locate.

Returns: A pointer to the Triangle2 if the point is inside the Zone2, otherwise NULL.

The first call to this method initializes a search structure. If boundary edges of the Zone2 are not constraint edges yet, constraint edges are created.

◆ morphClose()

Zone2* GEOM_FADE25D::Zone2::morphClose	(	Fade_2D *	pFade,
		double	offset,
		double	mergeAngleDeg = `10.0`,
		double	angleStep = `20.0`
	)		const

Morphological closing bridges small gaps between shapes by applying dilation (positive offset) followed by erosion (negative offset) using a disk-shaped structuring element whose radius can be chosen. The result is stored in a new Zone2 object, created within the provided Fade_2D object.

Left: The input zone, Right: The result of morphological closing - small gaps bridged.

Parameters

pFade	An empty `Fade_2D` object that will hold the result of the operation (the closed zone).
offset	The offset distance. It defines the radius of the disk-shaped structuring element. This value must be positive.
mergeAngleDeg	An angle threshold (in degrees). Circular arcs in the result which have an angle smaller than this value are collapsed into a single point. Recommended value: 91 degrees, to avoid most arcs.
angleStep	The angle interval (in degrees) at which circular arcs in the offset boundary, if any, are sampled using line segments. Default value: 20.0. Valid range: greater than 0 and up to 135.

Returns: A pointer to a new Zone2 object, created in pFade, representing the result of the morphological closing.

See also: https://www.geom.at/offset-polygon-example/#morphological_operations

◆ morphOpen()

Zone2* GEOM_FADE25D::Zone2::morphOpen	(	Fade_2D *	pFade,
		double	offset,
		double	mergeAngleDeg = `10.0`,
		double	angleStep = `20.0`
	)		const

Morphological opening removes small details from a shape by applying erosion (negative offset) followed by dilation (positive offset) using a disk-shaped structuring element whose radius can be chosen. The result is stored in a new Zone2 object, which is created in the provided Fade_2D object.

Left: The input zone, Right: The result of morphological opening - small details removed.

Parameters

pFade	An empty `Fade_2D` object in which the result will be created as a Zone2.
offset	The offset distance, which defines the radius of the disk-shaped structuring element. This value must be positive.
mergeAngleDeg	An angle threshold (in degrees). Circular arcs in the result which have an angle smaller than this value are collapsed into a single point. Recommended value: 91 degrees, to avoid most arcs.
angleStep	The angle interval (in degrees) at which circular arcs in the offset boundary, if any, are sampled using line segments. Default value: 20.0. Valid range: greater than 0 and up to 135.

Returns: A pointer to a new Zone2 object, created in pFade, representing the result of the morphological opening operation.

See also: https://www.geom.at/offset-polygon-example/#morphological_operations

Warning: The result of morphological opening may be empty! In such cases, this method returns NULL. Be sure to check for this condition before proceeding.

◆ numberOfConstraintGraphs()

size_t GEOM_FADE25D::Zone2::numberOfConstraintGraphs ( ) const

Retrieves the number of ConstraintGraph2 objects.

Returns: The number of ConstraintGraph2 objects associated with the current Zone2.

◆ save() [1/2]

bool GEOM_FADE25D::Zone2::save ( const char * filename )

This command saves the present Zone2 to a binary file. Any constraint edges and custom indices in the domain are retained.

Parameters

[in] filename is the output filename

Returns: whether the operation was successful

Note: A Delaunay triangulation is convex without holes but this may not hold for the Zone2 to be saved. Thus extra triangles may be saved to fill concavities. These extra-triangles will belong to the Fade_2D instance but not to the Zone2 object when reloaded.

See also: save(std::ostream& stream) is a similar command taking an ostream.; Fade_2D::saveZones(const char* file, std::vector<Zone2*>& vZones) is a similar command to store multiple Zone2 objects at once.; Fade_2D::saveTriangulation() stores the whole triangulation plus any specified Zone2 objects.; Fade_2D::load() can be used to reload the data from a file.

◆ save() [2/2]

bool GEOM_FADE25D::Zone2::save ( std::ostream & stream )

This command saves the present Zone2 to an ostream. Any constraint edges and custom indices in the domain are retained.

Parameters

stream is the output stream

Returns: whether the operation was successful

Note: A Delaunay triangulation is convex without holes but this may not hold for the Zone2 to be saved. Thus extra triangles may be saved to fill concavities. These extra-triangles will belong to the Fade_2D instance but not to the Zone2 object when reloaded.

See also: save(const char* filename) is a similar command taking an filename.; Fade_2D::saveZones(const char* file, std::vector<Zone2*>& vZones) is a similar command to store multiple Zone2 objects at once.; Fade_2D::saveTriangulation() stores the whole triangulation plus any specified Zone2 objects.; Fade_2D::load() can be used to reload the data from a file.

◆ shiftToZone()

bool GEOM_FADE25D::Zone2::shiftToZone	(	const Point2 &	q,
		double	tolerance,
		Point2 &	result
	)

This method finds a point close to the query point q that lies inside the Zone2 or on its boundary.

Parameters

[in]	q	A point outside the Zone2.
[in]	tolerance	The maximum allowed 2D distance to find a point on the Zone2.
[out]	result	A reference to store the point found within the Zone2, close to `q`.

Returns: true if a point within the zone is successfully found and returned as result; false otherwise.

The first call to this method initializes a search structure. If boundary edges of the Zone2 are not constraint edges yet, constraint edges are created.

◆ show() [1/4]

void GEOM_FADE25D::Zone2::show	(	const char *	filename,
		bool	bShowFull,
		bool	bWithConstraints
	)		const

This method visualizes and saves the Zone2 as a PDF or Postscript file.

Parameters

filename	The name of the output file. Use `.ps` or `.pdf` as the file extension.
bShowFull	Specifies whether only the Zone2 or the full triangulation should be drawn.
bWithConstraints	Specifies whether constraint edges should be drawn.

◆ show() [2/4]

void GEOM_FADE25D::Zone2::show	(	const char *	filename,
		const Colorname &	zoneFillColor = `CTRANSPARENT`,
		const Colorname &	zoneEdgeColor = `CBLACK`,
		const Colorname &	nonZoneFillColor = `CTRANSPARENT`,
		const Colorname &	nonZoneEdgeColor = `CTRANSPARENT`,
		const Colorname &	constraintEdgeColor = `CTRANSPARENT`
	)		const

This method visualizes and saves the Zone2 as a PDF or Postscript file.

Parameters

filename	The name of the output file. Use `.ps` or `.pdf` as the file extension.
zoneFillColor	The fill color for the zone triangles.
zoneEdgeColor	The edge color for the zone triangles.
nonZoneFillColor	The fill color for the non-zone triangles.
nonZoneEdgeColor	The edge color for the non-zone triangles.
constraintEdgeColor	The color for constraints.

Any of the colors can be chosen as CTRANSPARENT to avoid drawing the corresponding element.

◆ show() [3/4]

void GEOM_FADE25D::Zone2::show	(	Visualizer2 *	pVisualizer,
		bool	bShowFull,
		bool	bWithConstraints
	)		const

This method visualizes and saves the Zone2 as a PDF or Postscript file.

Parameters

pVisualizer	A pointer to an existing Visualizer2 object.
bShowFull	Specifies whether only the Zone2 or the full triangulation should be drawn.
bWithConstraints	Specifies whether constraint edges should be drawn.

Note: You must call pVisualizer->writeFile() before program end

◆ show() [4/4]

void GEOM_FADE25D::Zone2::show	(	Visualizer2 *	pVisualizer,
		const Colorname &	zoneFillColor = `CTRANSPARENT`,
		const Colorname &	zoneEdgeColor = `CBLACK`,
		const Colorname &	nonZoneFillColor = `CTRANSPARENT`,
		const Colorname &	nonZoneEdgeColor = `CTRANSPARENT`,
		const Colorname &	constraintEdgeColor = `CTRANSPARENT`
	)		const

This method visualizes and saves the Zone2 as a PDF or Postscript file.

Parameters

pVisualizer	A pointer to an existing Visualizer2 object.
zoneFillColor	The fill color for the zone triangles.
zoneEdgeColor	The edge color for the zone triangles.
nonZoneFillColor	The fill color for the non-zone triangles.
nonZoneEdgeColor	The edge color for the non-zone triangles.
constraintEdgeColor	The color for constraints.

Any of the colors can be chosen as CTRANSPARENT to avoid drawing the corresponding element.

◆ showGeomview() [1/2]

void GEOM_FADE25D::Zone2::showGeomview	(	const char *	filename,
		const char *	color
	)		const

This method visualizes the Zone2 by saving it as a file for the Geomview viewer (available for Linux only).

Parameters

filename	The name of the output file.
color	A string representing the color in the format "r g b a", for example, "1.0 0.0 0.0 1.0" for red.

See also: showVtk() for 3D visualizations under Windows.

◆ showGeomview() [2/2]

void GEOM_FADE25D::Zone2::showGeomview	(	Visualizer3 *	pVis,
		const char *	color
	)		const

This method visualizes the Zone2 by saving it as a file for the Geomview viewer (available for Linux only).

Parameters

pVis	points to a Visualizer3 object
color	A string representing the color in the format "r g b a", for example, "1.0 0.0 0.0 1.0" for red.

See also: showVtk() for 3D visualizations under Windows.

◆ showVtk() [1/2]

void GEOM_FADE25D::Zone2::showVtk	(	const char *	filename,
		VtkColor	zoneColor,
		VtkColor	nonZoneColor = `VTK_TRANSPARENT`,
		VtkColor	constraintColor = `VTK_TRANSPARENT`
	)		const

This method visualizes and saves the Zone2 as a VTK file, which can be viewed in tools like Paraview.

Parameters

filename	The name of the output file.
zoneColor	The color for the zone's triangles.
nonZoneColor	The color for the non-zone triangles. Use VTK_TRANSPARENT to prevent them from being drawn.
constraintColor	The color of the constraint edges. Use VTK_TRANSPARENT to prevent them from being drawn.

◆ showVtk() [2/2]

void GEOM_FADE25D::Zone2::showVtk	(	VtkWriter *	pVtk,
		VtkColor	zoneColor,
		VtkColor	nonZoneColor = `VTK_TRANSPARENT`,
		VtkColor	constraintColor = `VTK_TRANSPARENT`
	)		const

This method visualizes and saves the Zone2 as a VTK file, which can be viewed in tools like Paraview.

Parameters

pVtk	A VtkWriter object that may already contain other geometric objects
zoneColor	The color for the zone's triangles.
nonZoneColor	The color for the non-zone triangles. Use VTK_TRANSPARENT to prevent them from being drawn.
constraintColor	The color of the constraint edges. Use VTK_TRANSPARENT to prevent them from being drawn.

Note: Call pVtk->writeFile() to finally write the .vtk file.

◆ slopeValleyRidgeOptimization()

void GEOM_FADE25D::Zone2::slopeValleyRidgeOptimization ( OptimizationMode om = OPTMODE_BETTER )

Creating an elevated triangulation simply by lifting the points of a standard Delaunay triangulation ignores the z-coordinate of the vertices. As a result, valleys, ridges, and water bodies can appear unnatural. This method optimizes a Zone2 by keeping the points fixed while performing edge flips to alter the connectivity of the triangulation, resulting in a smoother surface overall.

Left: A lifted Delaunay triangulation. Right: Connectivity modified for smoother appearance

Parameters

om	The optimization mode: OPTMODE_NORMAL is the fastest option. OPTMODE_BETTER provides significantly better results while still being relatively fast. OPTMODE_BEST delivers the best results but with a significantly higher time requirement.

This method supports the progress-bar mechanism to track the process.

see https://www.geom.at/mesh-improvements/ This article discusses various mesh improvements.

◆ smoothing()

void GEOM_FADE25D::Zone2::smoothing	(	int	numIterations = `2`,
		bool	bWithXY = `true`
	)

Deprecated:: This method is deprecated but retained for backwards compatibility. Use the new method smoothing2() instead for better results.

Parameters

numIterations	is the number of smoothing passes.
bWithXY	specifies if the x and y coordinates are also adapted.

◆ smoothing2()

void GEOM_FADE25D::Zone2::smoothing2	(	int	numIterations,
		bool	bWithXY,
		bool	bWithConstraintZ
	)

A Zone2 before and after the smoothing operation.

This method performs weighted Laplacian smoothing on the vertices of the Zone2. It distinguishes two types of vertices:

Static vertices: These belong to constraint edges or border edges of the Zone2. Their x- and y-coordinates are never changed, while their z-coordinate may be modified depending on the value of the parameter bWithConstraintZ.
Dynamic vertices: These are all other vertices of the Zone2. Their z-coordinates can always be altered, while their x- and y-coordinates can only be changed if the value bWithXY is set to true.

Parameters

numIterations	The number of smoothing iterations to perform. Higher values yield smoother results; 2-3 iterations are recommended.
bWithXY	If set to `false`, only the z-coordinates of dynamic vertices are modified. If set to `true`, both the x- and y-coordinates of dynamic vertices can also be changed.
bWithConstraintZ	Controls whether the z-coordinates of static vertices can be modified by the smoothing process.

see https://www.geom.at/mesh-improvements/ This article discusses various mesh improvements.

◆ statistics()

void GEOM_FADE25D::Zone2::statistics ( const char * s ) const

Prints statistics.

◆ subscribe()

void GEOM_FADE25D::Zone2::subscribe	(	MsgType	msgType,
		MsgBase *	pMsg
	)

This method registers a subscriber to receive messages of a specified type.

Parameters

msgType	The type of message the subscriber will receive, e.g., `MSG_PROGRESS` or `MSG_WARNING`.
pMsg	A pointer to a custom class derived from `MsgBase` that will handle the messages.

◆ unifyGrid()

void GEOM_FADE25D::Zone2::unifyGrid ( double tolerance )

Left: A valid Delaunay triangulation. Right: Diagonals unified

A Delaunay triangulation is not unique when two or more triangles share a common circumcircle. For example, the four corners of a rectangle can be triangulated in two ways. This method unifies such cases by ensuring diagonals always go from the lower left to the upper right corner (or horizontally) for consistency and visual appearance.

Parameters

tolerance Defines the maximum allowed error in diagonal lengths due to noise or rounding errors. A value of 0 restricts changes to exact cases. The error is computed as: error = abs(diagonalA - diagonalB) / max(diagonalA, diagonalB)

◆ unsubscribe()

void GEOM_FADE25D::Zone2::unsubscribe	(	MsgType	msgType,
		MsgBase *	pMsg
	)

This method removes a subscriber from receiving messages of a specified type.

Parameters

msgType	The type of message that the subscriber will no longer receive.
pMsg	A pointer to a custom class derived from `MsgBase` representing the subscriber to be removed.

◆ writeObj()

void GEOM_FADE25D::Zone2::writeObj ( const char * filename ) const

This method writes the current Zone2 data to an .obj file, which can be used for visualization and further processing in tools like Meshlab.

Parameters

filename The output filename.

◆ writePly() [1/2]

bool GEOM_FADE25D::Zone2::writePly	(	const char *	filename,
		bool	bASCII = `false`
	)		const

This method writes the current Zone2 data to a *.ply file. The file can be saved in either ASCII or binary format.

Parameters

filename	The output filename.
bASCII	Specifies whether to write the *.ply file in ASCII format (true) or binary format (false). Default is false (binary).

Note: This method is available only on platforms that support C++11 or higher.

◆ writePly() [2/2]

bool GEOM_FADE25D::Zone2::writePly	(	std::ostream &	os,
		bool	bASCII = `false`
	)		const

This method writes the current Zone2 data to a *.ply file. The file can be saved in either ASCII or binary format.

Parameters

os	is the output stream
bASCII	Specifies whether to write the *.ply file in ASCII format (true) or binary format (false). Default is false (binary).

Note: This method is available only on platforms that support C++11 or higher.

Friends And Related Function Documentation

◆ peelOffIf [1/2]

CLASS_DECLSPEC friend Zone2* peelOffIf	(	Zone2 *	pZone,
		bool	bAvoidSplit,
		PeelPredicateTS *	pPredicate
	)

friend

Triangulations often contain narrow, nearly vertical triangles at their borders. This function returns a Zone2 that includes all triangles from pZone, except the undesired ones. If no triangles remain, the method returns NULL. A user-defined predicate distinguishes between desired and undesired triangles.

Left: A Zone2 containing nearly vertical border triangles. Right: Vertical border triangles removed.

Parameters

pZone	The input zone.
bAvoidSplit	If `true`, the algorithm removes a triangle only if it does not split the zone into independent components.
pPredicate	A user-defined predicate to decide whether a triangle should be removed.

Returns: A new Zone2 containing a subset of the triangles from pZone, or NULL if no triangles remain.

See also: C++ Example: Removing unwanted border triangles

◆ peelOffIf [2/2]

CLASS_DECLSPEC friend Zone2* peelOffIf	(	Zone2 *	pZone,
		UserPredicateT *	pPredicate,
		bool	bVerbose
	)

friend

Deprecated:: This function is DEPRECATED but kept for backwards compatibility. Use the new and better function peelOffIf(Zone2* pZone, bool bAvoidSplit,PeelPredicateTS* pPredicate)

◆ zoneDifference

CLASS_DECLSPEC friend Zone2* zoneDifference	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Left: pZone0, Middle: pZone1, Right: difference

This function returns a pointer to a new Zone2 object representing the difference between pZone0 and pZone1 (i.e., pZone0 minus pZone1). The input zones must belong to the same Fade_2D object.

Parameters

pZone0	Pointer to the first Zone2 object.
pZone1	Pointer to the second Zone2 object.

Returns: A pointer to a new Zone2 object representing the difference. If the result is empty, the function returns NULL. Be sure to check this case before proceeding.

◆ zoneIntersection

CLASS_DECLSPEC friend Zone2* zoneIntersection	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Left: pZone0, Middle: pZone1, Right: intersection

This function returns a pointer to a new Zone2 object representing the intersection of the two input zones. The intersection is the area covered by both input zones. The input zones must belong to the same Fade_2D object.

Parameters

pZone0	Pointer to the first Zone2 object.
pZone1	Pointer to the second Zone2 object.

Returns: A pointer to a new Zone2 object representing the intersection. If the result is empty, the function returns NULL. Be sure to check for this case before proceeding.

◆ zoneSymmetricDifference

CLASS_DECLSPEC friend Zone2* zoneSymmetricDifference	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Left: pZone0, Middle: pZone1, Right: symmetric difference

This function returns a pointer to a new Zone2 object representing the symmetric difference between the two input zones. The symmetric difference is the area covered by either of the input zones, but not by both. The input zones must belong to the same Fade_2D object.

Parameters

pZone0	Pointer to the first Zone2 object.
pZone1	Pointer to the second Zone2 object.

Returns: A pointer to the resulting Zone2 object representing the symmetric difference. If the result is empty, the function returns NULL. Be sure to check for this case before proceeding.

◆ zoneUnion

CLASS_DECLSPEC friend Zone2* zoneUnion	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Left: pZone0, Middle: pZone1, Right: union

This function returns a pointer to a new Zone2 object representing the union of the two input zones. The union is the area covered by either of the input zones. Both input zones must belong to the same Fade_2D object.

Parameters

pZone0	Pointer to the first Zone2 object.
pZone1	Pointer to the second Zone2 object.

Returns: A pointer to the resulting Zone2 object representing the union of the two zones.

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

Zone2.h

Public Member Functions

Protected Member Functions

Friends

Detailed Description

Member Function Documentation

◆ convertToBoundedZone()

◆ createOffsetZone()

◆ exportZone()

◆ getArea25D()

◆ getArea2D()

◆ getBorderEdges()

◆ getBoundarySegments()

◆ getComponentPolygons()

◆ getConstraintGraph()

◆ getMedianEdgeLength25D()

◆ getMedianEdgeLength2D()

◆ getNearbyBoundaryConstraint()

◆ getNumberOfTriangles()

◆ getOffsetBoundary()

◆ getTriangles()

◆ getZoneLocation()

◆ hasOn()

◆ hasOnBoundary()

◆ locate()

◆ morphClose()

◆ morphOpen()

◆ numberOfConstraintGraphs()

◆ save() [1/2]

◆ save() [2/2]

◆ shiftToZone()

◆ show() [1/4]

◆ show() [2/4]

◆ show() [3/4]

◆ show() [4/4]

◆ showGeomview() [1/2]

◆ showGeomview() [2/2]

◆ showVtk() [1/2]

◆ showVtk() [2/2]

◆ slopeValleyRidgeOptimization()

◆ smoothing()

◆ smoothing2()

◆ statistics()

◆ subscribe()

◆ unifyGrid()

◆ unsubscribe()

◆ writeObj()

◆ writePly() [1/2]

◆ writePly() [2/2]

Friends And Related Function Documentation

◆ peelOffIf [1/2]

◆ peelOffIf [2/2]

◆ zoneDifference

◆ zoneIntersection

◆ zoneSymmetricDifference

◆ zoneUnion