DDA< RayT, Log2Dim > Class Template Reference

A Digital Differential Analyzer specialized for OpenVDB grids. More...

#include <openvdb/math/DDA.h>

Public Types
using	RealType = typename RayT::RealType
using	RealT = RealType
using	Vec3Type = typename RayT::Vec3Type
using	Vec3T = Vec3Type

Public Member Functions
	DDA ()
	uninitialized constructor More...
	DDA (const RayT &ray)
	DDA (const RayT &ray, RealT startTime)
	DDA (const RayT &ray, RealT startTime, RealT maxTime)
void	init (const RayT &ray, RealT startTime, RealT maxTime)
void	init (const RayT &ray)
void	init (const RayT &ray, RealT startTime)
bool	step ()
	Increment the voxel index to next intersected voxel or node and returns true if the step in time does not exceed maxTime. More...
const Coord &	voxel () const
	Return the index coordinates of the next node or voxel intersected by the ray. If Log2Dim = 0 the return value is the actual signed coordinate of the voxel, else it is the origin of the corresponding VDB tree node or tile. More...
RealType	time () const
	Return the time (parameterized along the Ray) of the first hit of a tree node of size 2^Log2Dim. More...
RealType	maxTime () const
	Return the maximum time (parameterized along the Ray). More...
RealType	next () const
	Return the time (parameterized along the Ray) of the second (i.e. next) hit of a tree node of size 2^Log2Dim. More...
void	print (std::ostream &os=std::cout) const
	Print information about this DDA for debugging. More...

Detailed Description

template<typename RayT, Index Log2Dim = 0>
class openvdb::v9_0::math::DDA< RayT, Log2Dim >

A Digital Differential Analyzer specialized for OpenVDB grids.

Note

Conceptually similar to Bresenham's line algorithm applied to a 3D Ray intersecting OpenVDB nodes or voxels. Log2Dim = 0 corresponds to a voxel and Log2Dim a tree node of size 2^Log2Dim.

The Ray template class is expected to have the following methods: test(time), t0(), t1(), invDir(), and operator()(time). See the example Ray class above for their definition.

Member Typedef Documentation

using RealT = RealType

using RealType = typename RayT::RealType

using Vec3T = Vec3Type

using Vec3Type = typename RayT::Vec3Type

Constructor & Destructor Documentation

DDA ( )

inline

uninitialized constructor

DDA ( const RayT &  ray )

inline

DDA ( const RayT &  ray, RealT  startTime  )

inline

DDA ( const RayT &  ray, RealT  startTime, RealT  maxTime  )

inline

Member Function Documentation

void init ( const RayT &  ray, RealT  startTime, RealT  maxTime  )

inline

void init ( const RayT &  ray )

inline

void init ( const RayT &  ray, RealT  startTime  )

inline

RealType maxTime ( ) const

inline

Return the maximum time (parameterized along the Ray).

RealType next ( ) const

inline

Return the time (parameterized along the Ray) of the second (i.e. next) hit of a tree node of size 2^Log2Dim.

Note

Incurs a (small) computational overhead.

void print ( std::ostream &  os = std::cout ) const

inline

Print information about this DDA for debugging.

Parameters

os	a stream to which to write textual information.

bool step ( )

inline

Increment the voxel index to next intersected voxel or node and returns true if the step in time does not exceed maxTime.

RealType time ( ) const

inline

Return the time (parameterized along the Ray) of the first hit of a tree node of size 2^Log2Dim.

This value is initialized to startTime or ray.t0() depending on the constructor used.

Note

Incurs no computational overhead.

const Coord& voxel ( ) const

inline

Return the index coordinates of the next node or voxel intersected by the ray. If Log2Dim = 0 the return value is the actual signed coordinate of the voxel, else it is the origin of the corresponding VDB tree node or tile.

Note

Incurs no computational overhead.