LinearSearchImpl< GridT, Iterations, RealT > Class Template Reference

Implements linear iterative search for an iso-value of the level set along the direction of the ray. More...

#include <openvdb/tools/RayIntersector.h>

Public Types
using	RayT = math::Ray< RealT >
using	VecT = math::Vec3< RealT >
using	ValueT = typename GridT::ValueType
using	AccessorT = typename GridT::ConstAccessor
using	StencilT = math::BoxStencil< GridT >

Public Member Functions
	LinearSearchImpl (const GridT &grid, const ValueT &isoValue=zeroVal< ValueT >())
	Constructor from a grid. More...
const ValueT &	getIsoValue () const
	Return the iso-value used for ray-intersections. More...
bool	setIndexRay (const RayT &iRay)
	Return false if the ray misses the bbox of the grid. More...
bool	setWorldRay (const RayT &wRay)
	Return false if the ray misses the bbox of the grid. More...
void	getIndexPos (VecT &xyz) const
	Get the intersection point in index space. More...
void	getWorldPos (VecT &xyz) const
	Get the intersection point in world space. More...
void	getWorldPosAndNml (VecT &xyz, VecT &nml)
	Get the intersection point and normal in world space. More...
RealT	getIndexTime () const
	Return the time of intersection along the index ray. More...
RealT	getWorldTime () const
	Return the time of intersection along the world ray. More...

Friends
template<typename , int >
struct	math::LevelSetHDDA

Detailed Description

template<typename GridT, int Iterations, typename RealT>
class openvdb::v13_0::tools::LinearSearchImpl< GridT, Iterations, RealT >

Implements linear iterative search for an iso-value of the level set along the direction of the ray.

Note

Since this class is used internally in LevelSetRayIntersector (define above) and LevelSetHDDA (defined below) client code should never interact directly with its API. This also explains why we are not concerned with the fact that several of its methods are unsafe to call unless roots were already detected.

It is approximate due to the limited number of iterations which can can be defined with a template parameter. However the default value has proven surprisingly accurate and fast. In fact more iterations are not guaranteed to give significantly better results.

Warning

Since the root-searching algorithm is approximate (first-order) it is possible to miss intersections if the iso-value is too close to the inside or outside of the narrow band (typically a distance less than a voxel unit).

Since this class internally stores a ValueAccessor it is NOT thread-safe, so make sure to give each thread its own instance. This of course also means that the cost of allocating an instance should (if possible) be amortized over as many ray intersections as possible.

Member Typedef Documentation

using AccessorT = typename GridT::ConstAccessor

using RayT = math::Ray<RealT>

using StencilT = math::BoxStencil<GridT>

using ValueT = typename GridT::ValueType

using VecT = math::Vec3<RealT>

Constructor & Destructor Documentation

LinearSearchImpl ( const GridT &  grid, const ValueT &  isoValue = zeroVal<ValueT>()  )

inline

Constructor from a grid.

Exceptions

RunTimeError	if the grid is empty.
ValueError	if the isoValue is not inside the narrow-band.

Member Function Documentation

void getIndexPos ( VecT &  xyz ) const

inline

Get the intersection point in index space.

Parameters

xyz	The position in index space of the intersection.

RealT getIndexTime ( ) const

inline

Return the time of intersection along the index ray.

const ValueT& getIsoValue ( ) const

inline

Return the iso-value used for ray-intersections.

void getWorldPos ( VecT &  xyz ) const

inline

Get the intersection point in world space.

Parameters

xyz	The position in world space of the intersection.

void getWorldPosAndNml ( VecT &  xyz, VecT &  nml  )

inline

Get the intersection point and normal in world space.

Parameters

xyz	The position in world space of the intersection.
nml	The surface normal in world space of the intersection.

RealT getWorldTime ( ) const

inline

Return the time of intersection along the world ray.

bool setIndexRay ( const RayT &  iRay )

inline

Return false if the ray misses the bbox of the grid.

Parameters

iRay	Ray represented in index space.

Warning

Call this method before the ray traversal starts.

bool setWorldRay ( const RayT &  wRay )

inline

Return false if the ray misses the bbox of the grid.

Parameters

wRay	Ray represented in world space.

Warning

Call this method before the ray traversal starts.

Friends And Related Function Documentation

friend struct math::LevelSetHDDA

friend