When a Mesh object or modifier (such as Editable Mesh, Edit Mesh, or Mesh Select) handles viewport subobject selection, the flow is basically as follows from Editable Mesh. More...

#include <mnmesh.h>

Inheritance diagram for MNMeshSelectionConverter:

Public Member Functions
DllExport void	FaceToElement (MNMesh &mesh, BitArray &faceSel, BitArray &elementSel)
	Converts a face selection to an element selection. More...

DllExport void	EdgeToBorder (MNMesh &mesh, BitArray &edgeSel, BitArray &borderSel)

DllExport void	VertexToEdge (MNMesh &mesh, BitArray &vertexSel, BitArray &edgeSel)
	Converts a vertex selection to a "By Vertex" edge selection. More...

DllExport void	VertexToFace (MNMesh &mesh, BitArray &vertexSel, BitArray &faceSel)

Public Member Functions inherited from FlagUser
	FlagUser ()=default

	FlagUser (const FlagUser &)=default

	FlagUser (FlagUser &&)=default

FlagUser &	operator= (const FlagUser &)=default

FlagUser &	operator= (FlagUser &&)=default

void	SetFlag (DWORD fl, bool val=TRUE)

void	ClearFlag (DWORD fl)

bool	GetFlag (DWORD fl) const

void	ClearAllFlags ()

void	CopyFlags (DWORD fl)

void	CopyFlags (const FlagUser &fu)

void	CopyFlags (const FlagUser *fu)

void	CopyFlags (DWORD fl, DWORD mask)

void	CopyFlags (const FlagUser &fu, DWORD mask)

void	CopyFlags (const FlagUser *fu, DWORD mask)

void	OrFlags (const FlagUser &fu)

void	OrFlags (const FlagUser *fu)

void	AndFlags (const FlagUser &fu)

void	AndFlags (const FlagUser *fu)

bool	FlagMatch (DWORD fmask, DWORD fl) const

bool	FlagMatch (DWORD fmask, const FlagUser &fu) const

bool	FlagMatch (DWORD fmask, const FlagUser *fu) const

DWORD	ExportFlags () const

void	ImportFlags (DWORD fl)

IOResult	WriteFlags (ISave isave, ULONG nb) const

IOResult	ReadFlags (ILoad iload, ULONG nb)

Additional Inherited Members
Static Public Member Functions inherited from MaxHeapOperators
static UtilExport void *	operator new (size_t size)
	Standard new operator used to allocate objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e)
	Standard new operator used to allocate objects if there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new (size_t size, const char *filename, int line)
	New operator used to allocate objects that takes the filename and line number where the new was called If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, int block_type, const char *filename, int line)
	New operator used to allocate objects that takes the type of memory, filename and line number where the new was called If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e, const char *filename, int line)
	New operator used to allocate objects that takes the filename and line number where the new was called If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new (size_t size, unsigned long flags)
	New operator used to allocate objects that takes extra flags to specify special operations If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e, unsigned long flags)
	New operator used to allocate objects that takes extra flags to specify special operations If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size, const char *filename, int line)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, int block_type, const char *filename, int line)
	New operator used to allocate arrays of objects. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, const char *filename, int line)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size, unsigned long flags)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, unsigned long flags)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void	operator delete (void *ptr)
	Standard delete operator used to deallocate an object If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void *ptr, const std::nothrow_t &e)
	Standard delete operator used to deallocate an object If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete (void ptr, const char filename, int line)
	Delete operator used to deallocate an object that takes the filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void ptr, int block_type, const char filename, int line)
	Delete operator used to deallocate an object that takes the type of memory, filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void ptr, const std::nothrow_t &e, const char filename, int line)
	Delete operator used to deallocate an object that takes the filename and line number where the delete was called If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete (void *ptr, unsigned long flags)
	Delete operator used to deallocate an object that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void *ptr, const std::nothrow_t &e, unsigned long flags)
	Delete operator used to deallocate an object that takes extra flags to specify special operations If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void *ptr)
	Standard delete operator used to deallocate an array of objects If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void *ptr, const std::nothrow_t &e)
	Standard delete operator used to deallocate an array of objects If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void ptr, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void ptr, int block_type, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the type of memory, filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void ptr, const std::nothrow_t &e, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the filename and line number where the delete was called If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void *ptr, unsigned long flags)
	Delete operator used to deallocate an array of objects that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void *ptr, const std::nothrow_t &e, unsigned long flags)
	Delete operator used to deallocate an array of objects that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, void *placement_ptr)
	Placement new operator. More...

static UtilExport void	operator delete (void ptr, void placement_ptr)
	Placement delete operator. More...

static UtilExport void *	aligned_malloc (size_t size, size_t alignment)
	Allocates memory on a specified alignment boundary. More...

static UtilExport void *	aligned_realloc (void *ptr, size_t size, size_t alignment)
	Reallocates memory on a specified alignment boundary. More...

static UtilExport void	aligned_free (void *ptr)
	Frees a block of memory that was allocated with aligned_malloc/aligned_realloc. More...

Detailed Description

When a Mesh object or modifier (such as Editable Mesh, Edit Mesh, or Mesh Select) handles viewport subobject selection, the flow is basically as follows from Editable Mesh.

EditTriObject::HitTest is called with window information.
It passes the hit region description to Mesh::SubObjectHitTest
Mesh::SubObjectHitTest culls some subobjects (say, because they're backfacing), and creates hits for others that are within the hit region.
EditTriObject::SelectSubComponent is called with the list of hits, and

constructs the appropriate BitArray selection.

The problem was that in cases of Window selection, you want to only select an element or polygon if all the faces of that element or polygon were in the selection region. But since some of these faces could have been culled, they might not have hit records even if they're within the correct region. This would mean, for instance, that a window selection of an entire Sphere would fail to get select its single element, because all the backfaces would not

have been selected.

So in order to do this correctly, we need the face culling information. This information is stored and applied in the new MeshSelectionConverter interface, which is part of class Mesh.

This sort of culling and subobject level translation is not only relevant for Polygon and Element selections, but also for "By Vertex" selections of edges, faces, polygons, or elements.

Examples of the use of this interface are available in maxsdk/SAMPLES/mesh/editablemesh/triobjed.cpp, and in meshsel.cpp and editmesh.cpp in maxsdk/SAMPLES/modifiers..

Owner: class Mesh

InterfaceID: MESHSELECTCONVERT_INTERFACE

Flags:
We have the usual three methods for setting, clearing, and getting flags: void SetFlag (DWORD f, bool value=true) void ClearFlag(DWORD f) bool GetFlag (DWORD f)
We currently only have one flag influencing subobject selection conversion: MESH_SELCONV_REQUIRE_ALL
If set, it implies that, for instance, an element is only selected if all of its (non-culled) faces are selected. If cleared, an element is selected if any of its faces are selected.

Member Function Documentation

◆ FaceToElement()

DllExport void FaceToElement	(	MNMesh &	mesh,
		BitArray &	faceSel,
		BitArray &	elementSel
	)

Converts a face selection to an element selection.

This method can only produce accurate results with culling if we are certain that the face selection corresponds to the results of the last call to

the owner Mesh's SubObjectHitTest method. (To turn off culling, use GetCull ().ClearAll(). Culling is not relevant if the MESH_SELCONV_REQUIRE_ALL flag

is turned off.)

Parameters:: Mesh & mesh

The mesh that owns this interface

BitArray & faceSel

The face selection representing actual hits in the viewport.

BitArray & elementSel

This is where the output Element selection is stored.

◆ EdgeToBorder()

DllExport void EdgeToBorder	(	MNMesh &	mesh,
		BitArray &	edgeSel,
		BitArray &	borderSel
	)

◆ VertexToEdge()

DllExport void VertexToEdge	(	MNMesh &	mesh,
		BitArray &	vertexSel,
		BitArray &	edgeSel
	)

Converts a vertex selection to a "By Vertex" edge selection.

This method can only produce accurate results with culling if we are certain that the vertex selection corresponds to the results of the last call

to the owner Mesh's SubObjectHitTest method. (To turn off culling, use GetCull ().ClearAll(). Culling is not relevant if the MESH_SELCONV_REQUIRE_ALL flag

is turned off.)

Parameters:: Mesh & mesh

The mesh that owns this interface

BitArray & vertexSel

The face selection representing actual hits in the viewport

BitArray & edgeSel

The face selection representing actual hits in the viewport

◆ VertexToFace()

DllExport void VertexToFace	(	MNMesh &	mesh,
		BitArray &	vertexSel,
		BitArray &	faceSel
	)