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TopologyToLevelSet.h
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// Copyright Contributors to the OpenVDB Project
// SPDX-License-Identifier: MPL-2.0
//
/// @file TopologyToLevelSet.h
///
/// @brief This tool generates a narrow-band signed distance field / level set
/// from the interface between active and inactive voxels in a vdb grid.
///
/// @par Example:
/// Combine with @c tools::PointsToVolume for fast point cloud to level set conversion.
#ifndef OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
#define OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
#include "LevelSetFilter.h"
#include "Morphology.h" // for erodeActiveValues and dilateActiveValues
#include <openvdb/Grid.h>
#include <openvdb/Types.h>
#include <openvdb/math/FiniteDifference.h> // for math::BiasedGradientScheme
#include <openvdb/util/NullInterrupter.h>
#include <openvdb/openvdb.h>
#include <openvdb/points/PointDataGrid.h>
#include <tbb/task_group.h>
#include <algorithm> // for std::min(), std::max()
#include <vector>
namespace openvdb {
OPENVDB_USE_VERSION_NAMESPACE
namespace OPENVDB_VERSION_NAME {
namespace tools {
/// @brief Compute the narrow-band signed distance to the interface between
/// active and inactive voxels in the input grid.
///
/// @return A shared pointer to a new sdf / level set grid of type @c float
///
/// @param grid Input grid of arbitrary type whose active voxels are used
/// in constructing the level set.
/// @param halfWidth Half the width of the narrow band in voxel units.
/// @param closingSteps Number of morphological closing steps used to fill gaps
/// in the active voxel region.
/// @param dilation Number of voxels to expand the active voxel region.
/// @param smoothingSteps Number of smoothing interations.
template<typename GridT>
typename GridT::template ValueConverter<float>::Type::Ptr
topologyToLevelSet(const GridT& grid,
int halfWidth = 3,
int closingSteps = 1,
int dilation = 0,
int smoothingSteps = 0);
/// @brief Compute the narrow-band signed distance to the interface between
/// active and inactive voxels in the input grid.
///
/// @return A shared pointer to a new sdf / level set grid of type @c float
///
/// @param grid Input grid of arbitrary type whose active voxels are used
/// in constructing the level set.
/// @param halfWidth Half the width of the narrow band in voxel units.
/// @param closingSteps Number of morphological closing steps used to fill gaps
/// in the active voxel region.
/// @param dilation Number of voxels to expand the active voxel region.
/// @param smoothingSteps Number of smoothing interations.
/// @param interrupt Optional object adhering to the util::NullInterrupter interface.
template<typename GridT, typename InterrupterT>
typename GridT::template ValueConverter<float>::Type::Ptr
topologyToLevelSet(const GridT& grid,
int halfWidth = 3,
int closingSteps = 1,
int dilation = 0,
int smoothingSteps = 0,
InterrupterT* interrupt = nullptr);
////////////////////////////////////////
/// @cond OPENVDB_DOCS_INTERNAL
namespace ttls_internal {
template<typename TreeType>
struct OffsetAndMinComp
{
using LeafNodeType = typename TreeType::LeafNodeType;
using ValueType = typename TreeType::ValueType;
OffsetAndMinComp(std::vector<LeafNodeType*>& lhsNodes,
const TreeType& rhsTree,
ValueType offset)
: mLhsNodes(lhsNodes)
, mRhsTree(rhsTree)
, mOffset(offset) {}
void operator()(const tbb::blocked_range<size_t>& range) const
{
using Iterator = typename LeafNodeType::ValueOnIter;
tree::ValueAccessor<const TreeType> rhsAcc(mRhsTree);
const ValueType offset = mOffset;
for (size_t n = range.begin(), N = range.end(); n < N; ++n) {
LeafNodeType& lhsNode = *mLhsNodes[n];
const LeafNodeType* rhsNodePt = rhsAcc.probeConstLeaf(lhsNode.origin());
if (!rhsNodePt) continue;
auto* const data = lhsNode.buffer().data();
for (Iterator it = lhsNode.beginValueOn(); it; ++it) {
ValueType& val = data[it.pos()];
val = std::min(val, offset + rhsNodePt->getValue(it.pos()));
}
}
}
private:
std::vector<LeafNodeType*>& mLhsNodes;
const TreeType& mRhsTree;
const ValueType mOffset;
}; // struct OffsetAndMinComp
template<typename GridType, typename InterrupterType>
inline void
normalizeLevelSet(GridType& grid, const int halfWidthInVoxels, InterrupterType* interrupt = nullptr)
{
LevelSetFilter<GridType, GridType, InterrupterType> filter(grid, interrupt);
filter.setSpatialScheme(math::FIRST_BIAS);
filter.setNormCount(halfWidthInVoxels);
filter.normalize();
filter.prune();
}
template<typename GridType, typename InterrupterType>
inline void
smoothLevelSet(GridType& grid, int iterations, int halfBandWidthInVoxels,
InterrupterType* interrupt = nullptr)
{
using ValueType = typename GridType::ValueType;
using TreeType = typename GridType::TreeType;
using LeafNodeType = typename TreeType::LeafNodeType;
GridType filterGrid(grid);
LevelSetFilter<GridType, GridType, InterrupterType> filter(filterGrid, interrupt);
filter.setSpatialScheme(math::FIRST_BIAS);
for (int n = 0; n < iterations; ++n) {
if (interrupt && interrupt->wasInterrupted()) break;
filter.mean(1);
}
std::vector<LeafNodeType*> nodes;
grid.tree().getNodes(nodes);
const ValueType offset = ValueType(double(0.5) * grid.transform().voxelSize()[0]);
tbb::parallel_for(tbb::blocked_range<size_t>(0, nodes.size()),
OffsetAndMinComp<TreeType>(nodes, filterGrid.tree(), -offset));
// Clean up any damanage that was done by the min operation
normalizeLevelSet(grid, halfBandWidthInVoxels, interrupt);
}
} // namespace ttls_internal
/// @endcond
template<typename GridT, typename InterrupterT>
typename GridT::template ValueConverter<float>::Type::Ptr
topologyToLevelSet(const GridT& grid, int halfWidth, int closingSteps, int dilation,
int smoothingSteps, InterrupterT* interrupt)
{
using MaskTreeT = typename GridT::TreeType::template ValueConverter<ValueMask>::Type;
using FloatTreeT = typename GridT::TreeType::template ValueConverter<float>::Type;
using FloatGridT = Grid<FloatTreeT>;
// Check inputs
halfWidth = std::max(halfWidth, 1);
closingSteps = std::max(closingSteps, 0);
dilation = std::max(dilation, 0);
if (!grid.hasUniformVoxels()) {
OPENVDB_THROW(ValueError, "Non-uniform voxels are not supported!");
}
// Copy the topology into a MaskGrid.
MaskTreeT maskTree(grid.tree(), false/*background*/, openvdb::TopologyCopy());
// Morphological closing operation.
tools::dilateActiveValues(maskTree, closingSteps + dilation, tools::NN_FACE, tools::PRESERVE_TILES);
tools::erodeActiveValues(maskTree, /*iterations=*/closingSteps, tools::NN_FACE, tools::PRESERVE_TILES);
tools::pruneInactive(maskTree);
// Generate a volume with an implicit zero crossing at the boundary
// between active and inactive values in the input grid.
const float background = float(grid.voxelSize()[0]) * float(halfWidth);
typename FloatTreeT::Ptr lsTree(
new FloatTreeT(maskTree, /*out=*/background, /*in=*/-background, openvdb::TopologyCopy()));
tbb::task_group pool;
pool.run([&]() {
tools::erodeActiveValues(maskTree, /*iterations=*/halfWidth, tools::NN_FACE, tools::PRESERVE_TILES);
tools::pruneInactive(maskTree);
});
pool.run([&]() {
tools::dilateActiveValues(*lsTree, /*iterations=*/halfWidth, tools::NN_FACE, tools::PRESERVE_TILES);
});
pool.wait();// wait for both tasks to complete
lsTree->topologyDifference(maskTree);
maskTree.clear();
lsTree->voxelizeActiveTiles(); // has to come before ::pruneLevelSet
tools::pruneLevelSet(*lsTree, /*threading=*/true);
// Create a level set grid from the tree
typename FloatGridT::Ptr lsGrid = FloatGridT::create(lsTree);
lsGrid->setTransform(grid.transform().copy());
lsGrid->setGridClass(openvdb::GRID_LEVEL_SET);
// Use a PDE based scheme to propagate distance values from the
// implicit zero crossing.
ttls_internal::normalizeLevelSet(*lsGrid, 3*halfWidth, interrupt);
// Additional filtering
if (smoothingSteps > 0) {
ttls_internal::smoothLevelSet(*lsGrid, smoothingSteps, halfWidth, interrupt);
}
return lsGrid;
}
template<typename GridT>
typename GridT::template ValueConverter<float>::Type::Ptr
topologyToLevelSet(const GridT& grid, int halfWidth, int closingSteps, int dilation, int smoothingSteps)
{
util::NullInterrupter interrupt;
return topologyToLevelSet(grid, halfWidth, closingSteps, dilation, smoothingSteps, &interrupt);
}
////////////////////////////////////////
// Explicit Template Instantiation
#ifdef OPENVDB_USE_EXPLICIT_INSTANTIATION
#ifdef OPENVDB_INSTANTIATE_TOPOLOGYTOLEVELSET
#include <openvdb/util/ExplicitInstantiation.h>
#endif
#define _FUNCTION(TreeT) \
Grid<TreeT>::ValueConverter<float>::Type::Ptr topologyToLevelSet(const Grid<TreeT>&, int, int, int, int, \
util::NullInterrupter*)
OPENVDB_ALL_TREE_INSTANTIATE(_FUNCTION)
#undef _FUNCTION
#endif // OPENVDB_USE_EXPLICIT_INSTANTIATION
} // namespace tools
} // namespace OPENVDB_VERSION_NAME
} // namespace openvdb
#endif // OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
OPENVDB_THROW
#define OPENVDB_THROW(exception, message)
Definition Exceptions.h:74
ExplicitInstantiation.h
FiniteDifference.h
Grid.h
LevelSetFilter.h
Performs various types of level set deformations with interface tracking. These unrestricted deformat...
Morphology.h
Implementation of morphological dilation and erosion.
NullInterrupter.h
PointDataGrid.h
Attribute-owned data structure for points. Point attributes are stored in leaf nodes and ordered by v...
Types.h
openvdb::v11_0::Grid
Container class that associates a tree with a transform and metadata.
Definition Grid.h:571
openvdb::v11_0::TopologyCopy
Tag dispatch class that distinguishes topology copy constructors from deep copy constructors.
Definition Types.h:683
openvdb::v11_0::ValueError
Definition Exceptions.h:65
nanovdb::GridType
GridType
List of types that are currently supported by NanoVDB.
Definition NanoVDB.h:317
openvdb::v11_0::tools::topologyToLevelSet
GridT::template ValueConverter< float >::Type::Ptr topologyToLevelSet(const GridT &grid, int halfWidth=3, int closingSteps=1, int dilation=0, int smoothingSteps=0)
Compute the narrow-band signed distance to the interface between active and inactive voxels in the in...
Definition TopologyToLevelSet.h:245
openvdb::v11_0::GRID_LEVEL_SET
@ GRID_LEVEL_SET
Definition Types.h:455
openvdb
Definition Exceptions.h:13
openvdb.h
openvdb::v11_0::util::NullInterrupter
Base class for interrupters.
Definition NullInterrupter.h:26
OPENVDB_VERSION_NAME
#define OPENVDB_VERSION_NAME
The version namespace name for this library version.
Definition version.h.in:121
OPENVDB_USE_VERSION_NAMESPACE
#define OPENVDB_USE_VERSION_NAMESPACE
Definition version.h.in:212
OPENVDB_ALL_TREE_INSTANTIATE
#define OPENVDB_ALL_TREE_INSTANTIATE(Function)
Definition version.h.in:161