HDDA< RayT, CoordT > Class Template Reference

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

#include <nanovdb/util/HDDA.h>

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

Public Member Functions
	HDDA ()=default
	Default ctor. More...
__hostdev__	HDDA (const RayT &ray, int dim)
	ctor from ray and dimension at which the DDA marches More...
__hostdev__ void	init (const RayT &ray, RealT startTime, RealT maxTime, int dim)
	Re-initializes the HDDA. More...
__hostdev__ void	init (const RayT &ray, int dim)
	Simular to init above except it uses the bounds of the input ray. More...
__hostdev__ bool	update (const RayT &ray, int dim)
	Updates the HDDA to march with the specified dimension. More...
__hostdev__ int	dim () const
__hostdev__ 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...
__hostdev__ const CoordT &	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...
__hostdev__ RealType	time () const
	Return the time (parameterized along the Ray) of the first hit of a tree node of size 2^Log2Dim. More...
__hostdev__ RealType	maxTime () const
	Return the maximum time (parameterized along the Ray). More...
__hostdev__ 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...

Detailed Description

template<typename RayT, typename CoordT = Coord>
class nanovdb::HDDA< RayT, CoordT >

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 CoordType = CoordT

using RealT = RealType

using RealType = typename RayT::RealType

using Vec3T = Vec3Type

using Vec3Type = typename RayT::Vec3Type

Constructor & Destructor Documentation

HDDA ( )

default

Default ctor.

__hostdev__ HDDA ( const RayT &  ray, int  dim  )

inline

ctor from ray and dimension at which the DDA marches

Member Function Documentation

__hostdev__ int dim ( ) const

inline

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

inline

Re-initializes the HDDA.

__hostdev__ void init ( const RayT &  ray, int  dim  )

inline

Simular to init above except it uses the bounds of the input ray.

__hostdev__ RealType maxTime ( ) const

inline

Return the maximum time (parameterized along the Ray).

__hostdev__ 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.

__hostdev__ 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.

__hostdev__ 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.

__hostdev__ bool update ( const RayT &  ray, int  dim  )

inline

Updates the HDDA to march with the specified dimension.

__hostdev__ const CoordT& 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.