chrono::collision::ChConvexDecompositionJR Class Reference

Description

Class for wrapping the NvConvexDecomposition code by John W.

Ratcliff.

#include <ChCConvexDecomposition.h>

Inheritance diagram for chrono::collision::ChConvexDecompositionJR:

Collaboration diagram for chrono::collision::ChConvexDecompositionJR:

Public Member Functions
	ChConvexDecompositionJR ()
	Basic constructor.
virtual	~ChConvexDecompositionJR ()
	Destructor.
virtual void	Reset (void)
	Access directly the wrapped J.W.Ratcliff convex decomposition object although it shouldn't be necessary, since this class already provide wrapping to all the functions). More...
virtual bool	AddTriangle (const ChVector<> &v1, const ChVector<> &v2, const ChVector<> &v3)
	Add a triangle, by passing three points for vertexes. More...
virtual bool	AddTriangleMesh (const geometry::ChTriangleMesh &tm)
	Add a triangle mesh soup, by passing an entire ChTriangleMesh object. More...
void	SetParameters (float mskinWidth, unsigned int mdecompositionDepth, unsigned int mmaxHullVertices, float mconcavityThresholdPercent, float mmergeThresholdPercent, float mvolumeSplitThresholdPercent, bool museInitialIslandGeneration, bool museIslandGeneration)
	Set the parameters for this convex decomposition algorithm. More...
virtual int	ComputeConvexDecomposition ()
	Perform the convex decomposition. More...
virtual unsigned int	GetHullCount ()
	Get the number of computed hulls after the convex decomposition.
virtual bool	GetConvexHullResult (unsigned int hullIndex, geometry::ChTriangleMesh &convextrimesh)
	Get the n-th computed convex hull, by filling a ChTriangleMesh object that is passed as a parameter.
virtual bool	GetConvexHullResult (unsigned int hullIndex, std::vector< ChVector< double > > &convexhull)
	Get the n-th computed convex hull, by filling a vector of points of the vertexes of the n-th hull that is passed as a parameter.
virtual void	WriteConvexHullsAsWavefrontObj (ChStreamOutAscii &mstream)
	Save the computed convex hulls as a Wavefront file using the '.obj' fileformat, with each hull as a separate group. More...
Public Member Functions inherited from chrono::collision::ChConvexDecomposition
	ChConvexDecomposition ()
	Basic constructor.
virtual	~ChConvexDecomposition ()
	Destructor.
virtual bool	AddTriangle (const geometry::ChTriangle &t1)
	Add a triangle, by passing a ChTriangle object (that will be copied, not referenced). More...
virtual bool	WriteConvexHullsAsChullsFile (ChStreamOutAscii &mstream)
	Write the convex decomposition to a ".chulls" file, where each hull is a sequence of x y z coords. More...

Member Function Documentation

AddTriangle()

bool chrono::collision::ChConvexDecompositionJR::AddTriangle ( const ChVector<> &  v1, const ChVector<> &  v2, const ChVector<> &  v3  )

virtual

Add a triangle, by passing three points for vertexes.

Note: the vertexes must be properly ordered (oriented triangle, normal pointing outside)

Implements chrono::collision::ChConvexDecomposition.

AddTriangleMesh()

bool chrono::collision::ChConvexDecompositionJR::AddTriangleMesh ( const geometry::ChTriangleMesh &  tm )

virtual

Add a triangle mesh soup, by passing an entire ChTriangleMesh object.

Note 1: the triangle mesh does not need connectivity information (a basic 'triangle soup' is enough) Note 2: all vertexes must be properly ordered (oriented triangles, normals pointing outside). Note 3: the triangles must define closed volumes (holes, gaps in edges, etc. may trouble the decomposition)

Reimplemented from chrono::collision::ChConvexDecomposition.

ComputeConvexDecomposition()

int chrono::collision::ChConvexDecompositionJR::ComputeConvexDecomposition ( )

virtual

Perform the convex decomposition.

This operation is time consuming, and it may take a while to complete. Quality of the results can depend a lot on the parameters. Also, meshes with triangles that are not well oriented (normals always pointing outside) or with gaps/holes, may give wrong results.

Implements chrono::collision::ChConvexDecomposition.

Reset()

void chrono::collision::ChConvexDecompositionJR::Reset ( void  )

virtual

Access directly the wrapped J.W.Ratcliff convex decomposition object although it shouldn't be necessary, since this class already provide wrapping to all the functions).

Reset the input mesh data

Implements chrono::collision::ChConvexDecomposition.

SetParameters()

void chrono::collision::ChConvexDecompositionJR::SetParameters	(	float	mskinWidth,
		unsigned int	mdecompositionDepth,
		unsigned int	mmaxHullVertices,
		float	mconcavityThresholdPercent,
		float	mmergeThresholdPercent,
		float	mvolumeSplitThresholdPercent,
		bool	museInitialIslandGeneration,
		bool	museIslandGeneration
	)

Set the parameters for this convex decomposition algorithm.

Use this function before calling ComputeConvexDecomposition().

Parameters

mskinWidth	Skin width on the convex hulls generated
mdecompositionDepth	Recursion depth for convex decomposition.
mmaxHullVertices	Maximum number of vertices in output convex hulls.
mconcavityThresholdPercent	The percentage of concavity allowed without causing a split to occur.
mmergeThresholdPercent	The percentage of volume difference allowed to merge two convex hulls.
mvolumeSplitThresholdPercent	The percentage of the total volume of the object above which splits
museInitialIslandGeneration	will still occur. Whether or not to perform initial island generation on the input mesh.
museIslandGeneration	Whether or not to perform island generation at each split. Currently disabled.

WriteConvexHullsAsWavefrontObj()

void chrono::collision::ChConvexDecompositionJR::WriteConvexHullsAsWavefrontObj ( ChStreamOutAscii &  mstream )

virtual

Save the computed convex hulls as a Wavefront file using the '.obj' fileformat, with each hull as a separate group.

May throw exceptions if file locked etc.

Implements chrono::collision::ChConvexDecomposition.

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

• /builds/uwsbel/chrono/src/chrono/collision/ChCConvexDecomposition.h
• /builds/uwsbel/chrono/src/chrono/collision/ChCConvexDecomposition.cpp