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HDDA.h
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// Copyright Contributors to the OpenVDB Project
// SPDX-License-Identifier: MPL-2.0
/// @file HDDA.h
///
/// @author Ken Museth
///
/// @brief Hierarchical Digital Differential Analyzers specialized for VDB.
#ifndef NANOVDB_HDDA_H_HAS_BEEN_INCLUDED
#define NANOVDB_HDDA_H_HAS_BEEN_INCLUDED
// Comment out to disable this explicit round-off check
#define ENFORCE_FORWARD_STEPPING
#include <nanovdb/NanoVDB.h> // only dependency
namespace nanovdb {
/// @brief 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.
///
/// @note 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.
template<typename RayT, typename CoordT = Coord>
class HDDA
{
public:
using RealType = typename RayT::RealType;
using RealT = RealType;
using Vec3Type = typename RayT::Vec3Type;
using Vec3T = Vec3Type;
using CoordType = CoordT;
/// @brief Default ctor
HDDA() = default;
/// @brief ctor from ray and dimension at which the DDA marches
__hostdev__ HDDA(const RayT& ray, int dim) { this->init(ray, dim); }
/// @brief Re-initializes the HDDA
__hostdev__ void init(const RayT& ray, RealT startTime, RealT maxTime, int dim)
{
assert(startTime <= maxTime);
mDim = dim;
mT0 = startTime;
mT1 = maxTime;
const Vec3T &pos = ray(mT0), &dir = ray.dir(), &inv = ray.invDir();
mVoxel = RoundDown<CoordT>(pos) & (~(dim - 1));
for (int axis = 0; axis < 3; ++axis) {
if (dir[axis] == RealT(0)) { //handles dir = +/- 0
mNext[axis] = Maximum<RealT>::value(); //i.e. disabled!
mStep[axis] = 0;
} else if (inv[axis] > 0) {
mStep[axis] = 1;
mNext[axis] = mT0 + (mVoxel[axis] + dim - pos[axis]) * inv[axis];
mDelta[axis] = inv[axis];
} else {
mStep[axis] = -1;
mNext[axis] = mT0 + (mVoxel[axis] - pos[axis]) * inv[axis];
mDelta[axis] = -inv[axis];
}
}
}
/// @brief Simular to init above except it uses the bounds of the input ray
__hostdev__ void init(const RayT& ray, int dim) { this->init(ray, ray.t0(), ray.t1(), dim); }
/// @brief Updates the HDDA to march with the specified dimension
__hostdev__ bool update(const RayT& ray, int dim)
{
if (mDim == dim)
return false;
mDim = dim;
const Vec3T &pos = ray(mT0), &inv = ray.invDir();
mVoxel = RoundDown<CoordT>(pos) & (~(dim - 1));
for (int axis = 0; axis < 3; ++axis) {
if (mStep[axis] == 0)
continue;
mNext[axis] = mT0 + (mVoxel[axis] - pos[axis]) * inv[axis];
if (mStep[axis] > 0)
mNext[axis] += dim * inv[axis];
}
return true;
}
__hostdev__ int dim() const { return mDim; }
/// @brief Increment the voxel index to next intersected voxel or node
/// and returns true if the step in time does not exceed maxTime.
__hostdev__ bool step()
{
const int axis = MinIndex(mNext);
#if 1
switch (axis) {
case 0:
return step<0>();
case 1:
return step<1>();
default:
return step<2>();
}
#else
mT0 = mNext[axis];
mNext[axis] += mDim * mDelta[axis];
mVoxel[axis] += mDim * mStep[axis];
return mT0 <= mT1;
#endif
}
/// @brief 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.
__hostdev__ const CoordT& voxel() const { return mVoxel; }
/// @brief Return the time (parameterized along the Ray) of the
/// first hit of a tree node of size 2^Log2Dim.
/// @details This value is initialized to startTime or ray.t0()
/// depending on the constructor used.
/// @note Incurs no computational overhead.
__hostdev__ RealType time() const { return mT0; }
/// @brief Return the maximum time (parameterized along the Ray).
__hostdev__ RealType maxTime() const { return mT1; }
/// @brief 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__ RealType next() const
{
#if 1 //def __CUDA_ARCH__
return fminf(mT1, fminf(mNext[0], fminf(mNext[1], mNext[2])));
#else
return std::min(mT1, std::min(mNext[0], std::min(mNext[1], mNext[2])));
#endif
}
private:
// helper to implement the general form
template<int axis>
__hostdev__ bool step()
{
#ifdef ENFORCE_FORWARD_STEPPING
//if (mNext[axis] <= mT0) mNext[axis] += mT0 - mNext[axis] + fmaxf(mNext[axis]*1.0e-6f, 1.0e-6f);
//if (mNext[axis] <= mT0) mNext[axis] += mT0 - mNext[axis] + (mNext[axis] + 1.0f)*1.0e-6f;
if (mNext[axis] <= mT0) {
mNext[axis] += mT0 - 0.999999f * mNext[axis] + 1.0e-6f;
}
#endif
mT0 = mNext[axis];
mNext[ axis] += mDim * mDelta[axis];
mVoxel[axis] += mDim * mStep[ axis];
return mT0 <= mT1;
}
int32_t mDim;
RealT mT0, mT1; // min and max allowed times
CoordT mVoxel, mStep; // current voxel location and step to next voxel location
Vec3T mDelta, mNext; // delta time and next time
}; // class HDDA
/////////////////////////////////////////// ZeroCrossing ////////////////////////////////////////////
/// @brief returns true if the ray intersects a zero-crossing at the voxel level of the grid in the accessor
/// The empty-space ray-marching is performed at all levels of the tree using an
/// HDDA. If an intersection is detected, then ijk is updated with the index coordinate of the closest
/// voxel after the intersection point, v contains the grid values at ijk, and t is set to the time of
/// the intersection along the ray.
template<typename RayT, typename AccT>
inline __hostdev__ bool ZeroCrossing(RayT& ray, AccT& acc, Coord& ijk, typename AccT::ValueType& v, float& t)
{
if (!ray.clip(acc.root().bbox()) || ray.t1() > 1e20)
return false; // clip ray to bbox
static const float Delta = 1.0001f;
ijk = RoundDown<Coord>(ray.start()); // first hit of bbox
HDDA<RayT, Coord> hdda(ray, acc.getDim(ijk, ray));
const auto v0 = acc.getValue(ijk);
while (hdda.step()) {
ijk = RoundDown<Coord>(ray(hdda.time() + Delta));
hdda.update(ray, acc.getDim(ijk, ray));
if (hdda.dim() > 1 || !acc.isActive(ijk))
continue; // either a tile value or an inactive voxel
while (hdda.step() && acc.isActive(hdda.voxel())) { // in the narrow band
v = acc.getValue(hdda.voxel());
if (v * v0 < 0) { // zero crossing
ijk = hdda.voxel();
t = hdda.time();
return true;
}
}
}
return false;
}
/////////////////////////////////////////// DDA ////////////////////////////////////////////
/// @brief A Digital Differential Analyzer. Unlike HDDA (defined above) this DDA
/// uses a fixed step-size defined by the template parameter Dim!
///
/// @note 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.
template<typename RayT, typename CoordT = Coord, int Dim = 1>
class DDA
{
static_assert(Dim >= 1, "Dim must be >= 1");
public:
using RealType = typename RayT::RealType;
using RealT = RealType;
using Vec3Type = typename RayT::Vec3Type;
using Vec3T = Vec3Type;
using CoordType = CoordT;
/// @brief Default ctor
DDA() = default;
/// @brief ctor from ray and dimension at which the DDA marches
__hostdev__ DDA(const RayT& ray) { this->init(ray); }
/// @brief Re-initializes the DDA
__hostdev__ void init(const RayT& ray, RealT startTime, RealT maxTime)
{
assert(startTime <= maxTime);
mT0 = startTime;
mT1 = maxTime;
const Vec3T &pos = ray(mT0), &dir = ray.dir(), &inv = ray.invDir();
mVoxel = RoundDown<CoordT>(pos) & (~(Dim - 1));
for (int axis = 0; axis < 3; ++axis) {
if (dir[axis] == RealT(0)) { //handles dir = +/- 0
mNext[axis] = Maximum<RealT>::value(); //i.e. disabled!
mStep[axis] = 0;
} else if (inv[axis] > 0) {
mStep[axis] = Dim;
mNext[axis] = (mT0 + (mVoxel[axis] + Dim - pos[axis]) * inv[axis]);
mDelta[axis] = inv[axis];
} else {
mStep[axis] = -Dim;
mNext[axis] = mT0 + (mVoxel[axis] - pos[axis]) * inv[axis];
mDelta[axis] = -inv[axis];
}
}
}
/// @brief Simular to init above except it uses the bounds of the input ray
__hostdev__ void init(const RayT& ray) { this->init(ray, ray.t0(), ray.t1()); }
/// @brief Increment the voxel index to next intersected voxel or node
/// and returns true if the step in time does not exceed maxTime.
__hostdev__ bool step()
{
const int axis = MinIndex(mNext);
#if 1
switch (axis) {
case 0:
return step<0>();
case 1:
return step<1>();
default:
return step<2>();
}
#else
#ifdef ENFORCE_FORWARD_STEPPING
if (mNext[axis] <= mT0) {
mNext[axis] += mT0 - 0.999999f * mNext[axis] + 1.0e-6f;
}
#endif
mT0 = mNext[axis];
mNext[axis] += mDelta[axis];
mVoxel[axis] += mStep[axis];
return mT0 <= mT1;
#endif
}
/// @brief 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.
__hostdev__ const CoordT& voxel() const { return mVoxel; }
/// @brief Return the time (parameterized along the Ray) of the
/// first hit of a tree node of size 2^Log2Dim.
/// @details This value is initialized to startTime or ray.t0()
/// depending on the constructor used.
/// @note Incurs no computational overhead.
__hostdev__ RealType time() const { return mT0; }
/// @brief Return the maximum time (parameterized along the Ray).
__hostdev__ RealType maxTime() const { return mT1; }
/// @brief 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__ RealType next() const
{
return Min(mT1, Min(mNext[0], Min(mNext[1], mNext[2])));
}
__hostdev__ int nextAxis() const
{
return nanovdb::MinIndex(mNext);
}
private:
// helper to implement the general form
template<int axis>
__hostdev__ bool step()
{
#ifdef ENFORCE_FORWARD_STEPPING
if (mNext[axis] <= mT0) {
mNext[axis] += mT0 - 0.999999f * mNext[axis] + 1.0e-6f;
}
#endif
mT0 = mNext[axis];
mNext[axis] += mDelta[axis];
mVoxel[axis] += mStep[axis];
return mT0 <= mT1;
}
RealT mT0, mT1; // min and max allowed times
CoordT mVoxel, mStep; // current voxel location and step to next voxel location
Vec3T mDelta, mNext; // delta time and next time
}; // class DDA
/////////////////////////////////////////// ZeroCrossingNode ////////////////////////////////////////////
template<typename RayT, typename NodeT>
inline __hostdev__ bool ZeroCrossingNode(RayT& ray, const NodeT& node, float v0, nanovdb::Coord& ijk, float& v, float& t)
{
BBox<Coord> bbox(node.origin(), node.origin() + Coord(node.dim() - 1));
if (!ray.clip(node.bbox())) {
return false;
}
const float t0 = ray.t0();
static const float Delta = 1.0001f;
ijk = Coord::Floor(ray(ray.t0() + Delta));
t = t0;
v = 0;
DDA<RayT, Coord, 1 << NodeT::LOG2DIM> dda(ray);
while (dda.step()) {
ijk = dda.voxel();
if (bbox.isInside(ijk) == false)
return false;
v = node.getValue(ijk);
if (v * v0 < 0) {
t = dda.time();
return true;
}
}
return false;
}
/////////////////////////////////////////// TreeMarcher ////////////////////////////////////////////
/// @brief returns true if the ray intersects an active value at any level of the grid in the accessor.
/// The empty-space ray-marching is performed at all levels of the tree using an
/// HDDA. If an intersection is detected, then ijk is updated with the index coordinate of the first
/// active voxel or tile, and t is set to the time of its intersection along the ray.
template<typename RayT, typename AccT>
inline __hostdev__ bool firstActive(RayT& ray, AccT& acc, Coord &ijk, float& t)
{
if (!ray.clip(acc.root().bbox()) || ray.t1() > 1e20) {// clip ray to bbox
return false;// missed or undefined bbox
}
static const float Delta = 1.0001f;// forward step-size along the ray to avoid getting stuck
t = ray.t0();// initiate time
ijk = RoundDown<Coord>(ray.start()); // first voxel inside bbox
for (HDDA<RayT, Coord> hdda(ray, acc.getDim(ijk, ray)); !acc.isActive(ijk); hdda.update(ray, acc.getDim(ijk, ray))) {
if (!hdda.step()) return false;// leap-frog HDDA and exit if ray bound is exceeded
t = hdda.time() + Delta;// update time
ijk = RoundDown<Coord>( ray(t) );// update ijk
}
return true;
}
/////////////////////////////////////////// TreeMarcher ////////////////////////////////////////////
/// @brief A Tree Marcher for Generic Grids
template<typename NodeT, typename RayT, typename AccT, typename CoordT = Coord>
class TreeMarcher
{
public:
using ChildT = typename NodeT::ChildNodeType;
using RealType = typename RayT::RealType;
using RealT = RealType;
using CoordType = CoordT;
inline __hostdev__ TreeMarcher(AccT& acc)
: mAcc(acc)
{
}
/// @brief Initialize the TreeMarcher with an index-space ray.
inline __hostdev__ bool init(const RayT& indexRay)
{
mRay = indexRay;
if (!mRay.clip(mAcc.root().bbox()))
return false; // clip ray to bbox
// tweak the intersection span into the bbox.
// CAVEAT: this will potentially clip some tiny corner intersections.
static const float Eps = 0.000001f;
const float t0 = mRay.t0() + Eps;
const float t1 = mRay.t1() - Eps;
if (t0 > t1)
return false;
const CoordT ijk = RoundDown<Coord>(mRay(t0));
const uint32_t dim = mAcc.getDim(ijk, mRay);
mHdda.init(mRay, t0, t1, nanovdb::Max(dim, NodeT::dim()));
mT0 = (dim <= ChildT::dim()) ? mHdda.time() : -1; // potentially begin a span.
mTmax = t1;
return true;
}
/// @brief step the ray through the tree. If the ray hits a node then
/// populate t0 & t1, and the node.
/// @return true when a node of type NodeT is intersected, false otherwise.
inline __hostdev__ bool step(const NodeT** node, float& t0, float& t1)
{
// CAVEAT: if Delta is too large then it will clip corners of nodes in a visible way.
// but it has to be quite large when very far from the grid (due to fp32 rounding)
static const float Delta = 0.01f;
bool hddaIsValid;
do {
t0 = mT0;
auto currentNode = mAcc.template getNode<NodeT>();
// get next node intersection...
hddaIsValid = mHdda.step();
const CoordT nextIjk = RoundDown<Coord>(mRay(mHdda.time() + Delta));
const auto nextDim = mAcc.getDim(nextIjk, mRay);
mHdda.update(mRay, (int)Max(nextDim, NodeT::dim()));
mT0 = (nextDim <= ChildT::dim()) ? mHdda.time() : -1; // potentially begin a span.
if (t0 >= 0) { // we are in a span.
t1 = Min(mTmax, mHdda.time());
// TODO: clean this up!
if (t0 >= t1 || currentNode == nullptr)
continue;
*node = currentNode;
return true;
}
} while (hddaIsValid);
return false;
}
inline __hostdev__ const RayT& ray() const { return mRay; }
inline __hostdev__ RayT& ray() { return mRay; }
private:
AccT& mAcc;
RayT mRay;
HDDA<RayT, Coord> mHdda;
float mT0;
float mTmax;
};// TreeMarcher
/////////////////////////////////////////// PointTreeMarcher ////////////////////////////////////////////
/// @brief 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.
template<typename AccT, typename RayT, typename CoordT = Coord>
class PointTreeMarcher : public TreeMarcher<LeafNode<typename AccT::ValueType>, RayT, AccT, CoordT>
{
using BaseT = TreeMarcher<LeafNode<typename AccT::ValueType>, RayT, AccT, CoordT>;
public:
__hostdev__ PointTreeMarcher(AccT& acc) : BaseT(acc) {}
/// @brief Initiates this instance with a ray in index space.
///
/// @details 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__ bool init(RayT ray) { return BaseT::init(ray.offsetEye(0.5)); }
};// PointTreeMarcher
} // namespace nanovdb
#endif // NANOVDB_HDDA_HAS_BEEN_INCLUDED
NanoVDB.h
Implements a light-weight self-contained VDB data-structure in a single file! In other words,...
__hostdev__
#define __hostdev__
Definition NanoVDB.h:192
nanovdb::Coord
Signed (i, j, k) 32-bit integer coordinate class, similar to openvdb::math::Coord.
Definition NanoVDB.h:967
nanovdb::Coord::Floor
static Coord Floor(const Vec3T &xyz)
Return the largest integer coordinates that are not greater than xyz (node centered conversion).
Definition NanoVDB.h:1133
nanovdb::DDA
A Digital Differential Analyzer. Unlike HDDA (defined above) this DDA uses a fixed step-size defined ...
Definition HDDA.h:211
nanovdb::DDA::voxel
__hostdev__ const CoordT & voxel() const
Return the index coordinates of the next node or voxel intersected by the ray. If Log2Dim = 0 the ret...
Definition HDDA.h:286
nanovdb::DDA::CoordType
CoordT CoordType
Definition HDDA.h:219
nanovdb::DDA::maxTime
__hostdev__ RealType maxTime() const
Return the maximum time (parameterized along the Ray).
Definition HDDA.h:296
nanovdb::DDA::time
__hostdev__ RealType time() const
Return the time (parameterized along the Ray) of the first hit of a tree node of size 2^Log2Dim.
Definition HDDA.h:293
nanovdb::DDA::nextAxis
__hostdev__ int nextAxis() const
Definition HDDA.h:306
nanovdb::DDA::next
__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^...
Definition HDDA.h:301
nanovdb::DDA::DDA
__hostdev__ DDA(const RayT &ray)
ctor from ray and dimension at which the DDA marches
Definition HDDA.h:225
nanovdb::DDA::step
__hostdev__ bool step()
Increment the voxel index to next intersected voxel or node and returns true if the step in time does...
Definition HDDA.h:256
nanovdb::DDA::DDA
DDA()=default
Default ctor.
nanovdb::DDA::RealT
RealType RealT
Definition HDDA.h:216
nanovdb::DDA::Vec3T
Vec3Type Vec3T
Definition HDDA.h:218
nanovdb::DDA::init
__hostdev__ void init(const RayT &ray)
Simular to init above except it uses the bounds of the input ray.
Definition HDDA.h:252
nanovdb::DDA::init
__hostdev__ void init(const RayT &ray, RealT startTime, RealT maxTime)
Re-initializes the DDA.
Definition HDDA.h:228
nanovdb::DDA::Vec3Type
typename RayT::Vec3Type Vec3Type
Definition HDDA.h:217
nanovdb::DDA::RealType
typename RayT::RealType RealType
Definition HDDA.h:215
nanovdb::HDDA
A Digital Differential Analyzer specialized for OpenVDB grids.
Definition HDDA.h:30
nanovdb::HDDA::voxel
__hostdev__ const CoordT & voxel() const
Return the index coordinates of the next node or voxel intersected by the ray. If Log2Dim = 0 the ret...
Definition HDDA.h:120
nanovdb::HDDA::CoordType
CoordT CoordType
Definition HDDA.h:36
nanovdb::HDDA::maxTime
__hostdev__ RealType maxTime() const
Return the maximum time (parameterized along the Ray).
Definition HDDA.h:130
nanovdb::HDDA::init
__hostdev__ void init(const RayT &ray, int dim)
Simular to init above except it uses the bounds of the input ray.
Definition HDDA.h:70
nanovdb::HDDA::HDDA
__hostdev__ HDDA(const RayT &ray, int dim)
ctor from ray and dimension at which the DDA marches
Definition HDDA.h:42
nanovdb::HDDA::time
__hostdev__ RealType time() const
Return the time (parameterized along the Ray) of the first hit of a tree node of size 2^Log2Dim.
Definition HDDA.h:127
nanovdb::HDDA::next
__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^...
Definition HDDA.h:135
nanovdb::HDDA::init
__hostdev__ void init(const RayT &ray, RealT startTime, RealT maxTime, int dim)
Re-initializes the HDDA.
Definition HDDA.h:45
nanovdb::HDDA::dim
__hostdev__ int dim() const
Definition HDDA.h:91
nanovdb::HDDA::step
__hostdev__ bool step()
Increment the voxel index to next intersected voxel or node and returns true if the step in time does...
Definition HDDA.h:95
nanovdb::HDDA::RealT
RealType RealT
Definition HDDA.h:33
nanovdb::HDDA::Vec3T
Vec3Type Vec3T
Definition HDDA.h:35
nanovdb::HDDA::Vec3Type
typename RayT::Vec3Type Vec3Type
Definition HDDA.h:34
nanovdb::HDDA::HDDA
HDDA()=default
Default ctor.
nanovdb::HDDA::RealType
typename RayT::RealType RealType
Definition HDDA.h:32
nanovdb::HDDA::update
__hostdev__ bool update(const RayT &ray, int dim)
Updates the HDDA to march with the specified dimension.
Definition HDDA.h:73
nanovdb::PointTreeMarcher::PointTreeMarcher
__hostdev__ PointTreeMarcher(AccT &acc)
Definition HDDA.h:494
nanovdb::PointTreeMarcher::init
__hostdev__ bool init(RayT ray)
Initiates this instance with a ray in index space.
Definition HDDA.h:505
nanovdb::TreeMarcher::CoordType
CoordT CoordType
Definition HDDA.h:401
nanovdb::TreeMarcher::step
__hostdev__ bool step(const NodeT **node, float &t0, float &t1)
step the ray through the tree. If the ray hits a node then populate t0 & t1, and the node.
Definition HDDA.h:435
nanovdb::TreeMarcher::ray
__hostdev__ const RayT & ray() const
Definition HDDA.h:470
nanovdb::TreeMarcher::ChildT
typename NodeT::ChildNodeType ChildT
Definition HDDA.h:398
nanovdb::TreeMarcher::ray
__hostdev__ RayT & ray()
Definition HDDA.h:472
nanovdb::TreeMarcher::RealT
RealType RealT
Definition HDDA.h:400
nanovdb::TreeMarcher::init
__hostdev__ bool init(const RayT &indexRay)
Initialize the TreeMarcher with an index-space ray.
Definition HDDA.h:409
nanovdb::TreeMarcher::TreeMarcher
__hostdev__ TreeMarcher(AccT &acc)
Definition HDDA.h:403
nanovdb::TreeMarcher::RealType
typename RayT::RealType RealType
Definition HDDA.h:399
nanovdb
Definition NanoVDB.h:208
nanovdb::MinIndex
int MinIndex(const Vec3T &v)
Definition NanoVDB.h:917
nanovdb::Min
Type Min(Type a, Type b)
Definition NanoVDB.h:758
nanovdb::ZeroCrossing
__hostdev__ bool ZeroCrossing(RayT &ray, AccT &acc, Coord &ijk, typename AccT::ValueType &v, float &t)
returns true if the ray intersects a zero-crossing at the voxel level of the grid in the accessor The...
Definition HDDA.h:176
nanovdb::firstActive
__hostdev__ bool firstActive(RayT &ray, AccT &acc, Coord &ijk, float &t)
returns true if the ray intersects an active value at any level of the grid in the accessor....
Definition HDDA.h:374
nanovdb::RoundDown
CoordT RoundDown(const Vec3T< RealT > &xyz)
Definition NanoVDB.h:895
nanovdb::Max
Type Max(Type a, Type b)
Definition NanoVDB.h:779
nanovdb::ZeroCrossingNode
__hostdev__ bool ZeroCrossingNode(RayT &ray, const NodeT &node, float v0, nanovdb::Coord &ijk, float &v, float &t)
Definition HDDA.h:335
nanovdb::BBox
Definition NanoVDB.h:1655
nanovdb::Delta
Delta for small floating-point offsets.
Definition NanoVDB.h:704
nanovdb::Maximum::value
static T value()
Definition NanoVDB.h:746