PointTreeMarcher< AccT, RayT, CoordT > Class Template Reference

A Tree Marcher for Point Grids. More...

#include <nanovdb/util/HDDA.h>

Inherits TreeMarcher< LeafNode< AccT::ValueType >, RayT, AccT, CoordT >.

Public Types
using	ChildT = typename LeafNode< AccT::ValueType >::ChildNodeType
using	RealType = typename RayT::RealType
using	RealT = RealType
using	CoordType = CoordT

Public Member Functions
__hostdev__	PointTreeMarcher (AccT &acc)
__hostdev__ bool	init (RayT ray)
	Initiates this instance with a ray in index space. More...
__hostdev__ bool	init (const RayT &indexRay)
	Initialize the TreeMarcher with an index-space ray. More...
__hostdev__ bool	step (const LeafNode< AccT::ValueType > **node, float &t0, float &t1)
	step the ray through the tree. If the ray hits a node then populate t0 & t1, and the node. More...
__hostdev__ const RayT &	ray () const
__hostdev__ RayT &	ray ()

Detailed Description

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

A Tree Marcher for Point Grids.

Note

This class will handle correctly offseting the ray by 0.5 to ensure that the underlying HDDA will intersect with the grid-cells. See details below.

Member Typedef Documentation

using ChildT = typename LeafNode< AccT::ValueType > ::ChildNodeType

inherited

using CoordType = CoordT

inherited

using RealT = RealType

inherited

using RealType = typename RayT::RealType

inherited

Constructor & Destructor Documentation

__hostdev__ PointTreeMarcher ( AccT &  acc )

inline

Member Function Documentation

__hostdev__ bool init ( const RayT &  indexRay )

inlineinherited

Initialize the TreeMarcher with an index-space ray.

__hostdev__ bool init ( RayT  ray )

inline

Initiates this instance with a ray in index space.

An offset by 0.5 is applied to the ray to account for the fact that points in vdb grids are bucketed into so-called grid cell, which are centered round grid voxels, whereas the DDA is based on so-called grid nodes, which are coincident with grid voxels. So, rather than offsettting the points by 0.5 to bring them into a grid node representation this method offsets the eye of the ray by 0.5, which effectively ensures that the DDA operates on grid cells as oppose to grid nodes. This subtle but important offset by 0.5 is explined in more details in our online documentation.

__hostdev__ const RayT& ray ( ) const

inlineinherited

__hostdev__ RayT& ray ( )

inlineinherited

__hostdev__ bool step ( const LeafNode< AccT::ValueType > **  node, float &  t0, float &  t1  )

inlineinherited

step the ray through the tree. If the ray hits a node then populate t0 & t1, and the node.

Returns

true when a node of type NodeT is intersected, false otherwise.