#include <nanovdb/util/Stencils.h>

Inherits BaseStencil< GradStencil< GridT >, 7, GridT >.

Public Types
using	GridType = GridT

using	TreeType = typename GridT::TreeType

using	ValueType = typename GridT::ValueType

using	AccessorType = typename GridT::AccessorType

Public Member Functions
__hostdev__	GradStencil (const GridType &grid)

__hostdev__	GradStencil (const GridType &grid, double dx)

__hostdev__ ValueType	normSqGrad () const
	Return the norm square of the single-sided upwind gradient (computed via Godunov's scheme) at the previously buffered location. More...

__hostdev__ Vec3< ValueType >	gradient () const
	Return the gradient computed at the previously buffered location by second order central differencing. More...

__hostdev__ Vec3< ValueType >	gradient (const Vec3< ValueType > &V) const
	Return the first-order upwind gradient corresponding to the direction V. More...

__hostdev__ ValueType	laplacian () const

__hostdev__ bool	zeroCrossing () const

__hostdev__ Vec3< ValueType >	cpt ()
	Compute the closest-point transform to a level set. More...

template<int i, int j, int k>
__hostdev__ unsigned int	pos () const
	Return linear offset for the specified stencil point relative to its center. More...

__hostdev__ void	moveTo (const Coord &ijk)
	Initialize the stencil buffer with the values of voxel (i, j, k) and its neighbors. More...

__hostdev__ void	moveTo (const Coord &ijk, const ValueType &centerValue)
	Initialize the stencil buffer with the values of voxel (i, j, k) and its neighbors. The method also takes a value of the center element of the stencil, assuming it is already known. More...

__hostdev__ void	moveTo (const IterType &iter)
	Initialize the stencil buffer with the values of voxel (x, y, z) and its neighbors. More...

__hostdev__ void	moveTo (const Vec3< RealType > &xyz)
	Initialize the stencil buffer with the values of voxel (x, y, z) and its neighbors. More...

__hostdev__ const ValueType &	getValue (unsigned int pos=0) const
	Return the value from the stencil buffer with linear offset pos. More...

__hostdev__ const ValueType &	getValue () const
	Return the value at the specified location relative to the center of the stencil. More...

__hostdev__ void	setValue (const ValueType &value)
	Set the value at the specified location relative to the center of the stencil. More...

__hostdev__ ValueType	mean () const
	Return the mean value of the current stencil. More...

__hostdev__ ValueType	min () const
	Return the smallest value in the stencil buffer. More...

__hostdev__ ValueType	max () const
	Return the largest value in the stencil buffer. More...

__hostdev__ const Coord &	getCenterCoord () const
	Return the coordinates of the center point of the stencil. More...

__hostdev__ const ValueType &	getCenterValue () const
	Return the value at the center of the stencil. More...

__hostdev__ bool	intersects (const ValueType &isoValue=ValueType(0)) const
	Return true if the center of the stencil intersects the iso-contour specified by the isoValue. More...

__hostdev__ Mask	intersectionMask (ValueType isoValue=ValueType(0)) const
	Return true a bit-mask where the 6 lower bits indicates if the center of the stencil intersects the iso-contour specified by the isoValue. More...

__hostdev__ const GridType &	grid () const
	Return a const reference to the grid from which this stencil was constructed. More...

__hostdev__ const AccessorType &	accessor () const
	Return a const reference to the ValueAccessor associated with this Stencil. More...

Static Public Member Functions
static __hostdev__ int	size ()
	Return the size of the stencil buffer. More...

Static Public Attributes
static constexpr int	SIZE = 7

Protected Attributes
const GridType *	mGrid

AccessorType	mAcc

ValueType	mValues [SIZE]

Coord	mCenter

Friends
template<typename , int , typename >
class	BaseStencil

Detailed Description

template<typename GridT>
class nanovdb::GradStencil< GridT >

This is a simple 7-point nearest neighbor stencil that supports gradient by second-order central differencing, first-order upwinding, Laplacian, closest-point transform and zero-crossing test.

Note: For optimal random access performance this class includes its own grid accessor.

Member Typedef Documentation

using AccessorType = typename GridT::AccessorType

inherited

using GridType = GridT

using TreeType = typename GridT::TreeType

using ValueType = typename GridT::ValueType

Constructor & Destructor Documentation

__hostdev__ GradStencil ( const GridType & grid )

inline

__hostdev__ GradStencil	(	const GridType &	grid,
		double	dx
	)

inline

Member Function Documentation

__hostdev__ const AccessorType& accessor ( ) const

inlineinherited

Return a const reference to the ValueAccessor associated with this Stencil.

__hostdev__ Vec3<ValueType> cpt ( )

inline

Compute the closest-point transform to a level set.

Returns: the closest point in index space to the surface from which the level set was derived.

Note: This method assumes that the grid represents a level set with distances in world units and a simple affine transfrom with uniform scaling.

__hostdev__ const Coord& getCenterCoord ( ) const

inlineinherited

Return the coordinates of the center point of the stencil.

__hostdev__ const ValueType& getCenterValue ( ) const

inlineinherited

Return the value at the center of the stencil.

__hostdev__ const ValueType& getValue ( unsigned int pos = 0 ) const

inlineinherited

Return the value from the stencil buffer with linear offset pos.

Note: The default (pos = 0) corresponds to the first element which is typically the center point of the stencil.

__hostdev__ const ValueType& getValue ( ) const

inlineinherited

Return the value at the specified location relative to the center of the stencil.

__hostdev__ Vec3<ValueType> gradient ( ) const

inline

Return the gradient computed at the previously buffered location by second order central differencing.

Note: This method should not be called until the stencil buffer has been populated via a call to moveTo(ijk).

__hostdev__ Vec3<ValueType> gradient ( const Vec3< ValueType > & V ) const

inline

Return the first-order upwind gradient corresponding to the direction V.

Note: This method should not be called until the stencil buffer has been populated via a call to moveTo(ijk).

__hostdev__ const GridType& grid ( ) const

inlineinherited

Return a const reference to the grid from which this stencil was constructed.

__hostdev__ Mask intersectionMask ( ValueType isoValue = ValueType(0) ) const

inlineinherited

Return true a bit-mask where the 6 lower bits indicates if the center of the stencil intersects the iso-contour specified by the isoValue.

Note: There are 2^6 = 64 different possible cases, including no intersections!

The ordering of bit mask is ( -x, +x, -y, +y, -z, +z ), so to check if there is an intersection in -y use (mask & (1u<<2)) where mask is ther return value from this function. To check if there are any intersections use mask!=0u, and for no intersections use mask==0u. To count the number of intersections use __builtin_popcount(mask).

__hostdev__ bool intersects ( const ValueType & isoValue = ValueType(0) ) const

inlineinherited

Return true if the center of the stencil intersects the iso-contour specified by the isoValue.

__hostdev__ ValueType laplacian ( ) const

inline

Return the Laplacian computed at the previously buffered location by second-order central differencing.

__hostdev__ ValueType max ( ) const

inlineinherited

Return the largest value in the stencil buffer.

__hostdev__ ValueType mean ( ) const

inlineinherited

Return the mean value of the current stencil.

__hostdev__ ValueType min ( ) const

inlineinherited

Return the smallest value in the stencil buffer.

__hostdev__ void moveTo ( const Coord & ijk )

inlineinherited

Initialize the stencil buffer with the values of voxel (i, j, k) and its neighbors.

Parameters

ijk	Index coordinates of stencil center

__hostdev__ void moveTo	(	const Coord &	ijk,
		const ValueType &	centerValue
	)

inlineinherited

Initialize the stencil buffer with the values of voxel (i, j, k) and its neighbors. The method also takes a value of the center element of the stencil, assuming it is already known.

Parameters

ijk	Index coordinates of stencil center
centerValue	Value of the center element of the stencil

__hostdev__ void moveTo ( const IterType & iter )

inlineinherited

Initialize the stencil buffer with the values of voxel (x, y, z) and its neighbors.

Note: This version is slightly faster than the one above, since the center voxel's value is read directly from the iterator.

__hostdev__ void moveTo ( const Vec3< RealType > & xyz )

inlineinherited

Initialize the stencil buffer with the values of voxel (x, y, z) and its neighbors.

Parameters

xyz	Floating point voxel coordinates of stencil center

This method will check to see if it is necessary to update the stencil based on the cached index coordinates of the center point.

__hostdev__ ValueType normSqGrad ( ) const

inline

Return the norm square of the single-sided upwind gradient (computed via Godunov's scheme) at the previously buffered location.

Note: This method should not be called until the stencil buffer has been populated via a call to moveTo(ijk).

__hostdev__ unsigned int pos ( ) const

inline

Return linear offset for the specified stencil point relative to its center.

__hostdev__ void setValue ( const ValueType & value )

inlineinherited

Set the value at the specified location relative to the center of the stencil.

static __hostdev__ int size ( )

inlinestaticinherited

Return the size of the stencil buffer.

__hostdev__ bool zeroCrossing ( ) const

inline

Return true if the sign of the value at the center point of the stencil is different from the signs of any of its six nearest neighbors.

Friends And Related Function Documentation

friend class BaseStencil

friend

Member Data Documentation

AccessorType mAcc

protectedinherited

Coord mCenter

protectedinherited

const GridType* mGrid

protectedinherited

ValueType mValues[SIZE]

protectedinherited

constexpr int SIZE = 7

static

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Attributes

Friends

Detailed Description

template<typename GridT> class nanovdb::GradStencil< GridT >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation

template<typename GridT>
class nanovdb::GradStencil< GridT >