OpenVDB 13.0.0

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TopologyToLevelSet.h
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1// Copyright Contributors to the OpenVDB Project
2// SPDX-License-Identifier: Apache-2.0
3//
4/// @file TopologyToLevelSet.h
5///
6/// @brief This tool generates a narrow-band signed distance field / level set
7/// from the interface between active and inactive voxels in a vdb grid.
8///
9/// @par Example:
10/// Combine with @c tools::PointsToVolume for fast point cloud to level set conversion.
11
12#ifndef OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
13#define OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
14
15#include "LevelSetFilter.h"
16#include "Morphology.h" // for erodeActiveValues and dilateActiveValues
17
18#include <openvdb/Grid.h>
19#include <openvdb/Types.h>
20#include <openvdb/math/FiniteDifference.h> // for math::BiasedGradientScheme
21#include <openvdb/util/NullInterrupter.h>
22#include <openvdb/openvdb.h>
23#include <openvdb/points/PointDataGrid.h>
24
25#include <tbb/task_group.h>
26
27#include <algorithm> // for std::min(), std::max()
28#include <vector>
29
30
31 namespace openvdb {
32 OPENVDB_USE_VERSION_NAMESPACE
33 namespace OPENVDB_VERSION_NAME {
34 namespace tools {
35
36
37/// @brief Compute the narrow-band signed distance to the interface between
38/// active and inactive voxels in the input grid.
39///
40/// @return A shared pointer to a new sdf / level set grid of type @c float
41///
42/// @param grid Input grid of arbitrary type whose active voxels are used
43/// in constructing the level set.
44/// @param halfWidth Half the width of the narrow band in voxel units.
45/// @param closingSteps Number of morphological closing steps used to fill gaps
46/// in the active voxel region.
47/// @param dilation Number of voxels to expand the active voxel region.
48/// @param smoothingSteps Number of smoothing interations.
49 template<typename GridT>
50 typename GridT::template ValueConverter<float>::Type::Ptr
51 topologyToLevelSet(const GridT& grid,
52 int halfWidth = 3,
53 int closingSteps = 1,
54 int dilation = 0,
55 int smoothingSteps = 0);
56
57
58/// @brief Compute the narrow-band signed distance to the interface between
59/// active and inactive voxels in the input grid.
60///
61/// @return A shared pointer to a new sdf / level set grid of type @c float
62///
63/// @param grid Input grid of arbitrary type whose active voxels are used
64/// in constructing the level set.
65/// @param halfWidth Half the width of the narrow band in voxel units.
66/// @param closingSteps Number of morphological closing steps used to fill gaps
67/// in the active voxel region.
68/// @param dilation Number of voxels to expand the active voxel region.
69/// @param smoothingSteps Number of smoothing interations.
70/// @param interrupt Optional object adhering to the util::NullInterrupter interface.
71 template<typename GridT, typename InterrupterT>
72 typename GridT::template ValueConverter<float>::Type::Ptr
73 topologyToLevelSet(const GridT& grid,
74 int halfWidth = 3,
75 int closingSteps = 1,
76 int dilation = 0,
77 int smoothingSteps = 0,
78 InterrupterT* interrupt = nullptr);
79
80
81////////////////////////////////////////
82
83/// @cond OPENVDB_DOCS_INTERNAL
84
85 namespace ttls_internal {
86
87
88 template<typename TreeType>
89 struct OffsetAndMinComp
90{
91 using LeafNodeType = typename TreeType::LeafNodeType;
92 using ValueType = typename TreeType::ValueType;
93
94 OffsetAndMinComp(std::vector<LeafNodeType*>& lhsNodes,
95 const TreeType& rhsTree,
96 ValueType offset)
97 : mLhsNodes(lhsNodes)
98 , mRhsTree(rhsTree)
99 , mOffset(offset) {}
100
101 void operator()(const tbb::blocked_range<size_t>& range) const
102 {
103 using Iterator = typename LeafNodeType::ValueOnIter;
104
105 tree::ValueAccessor<const TreeType> rhsAcc(mRhsTree);
106 const ValueType offset = mOffset;
107
108 for (size_t n = range.begin(), N = range.end(); n < N; ++n) {
109
110 LeafNodeType& lhsNode = *mLhsNodes[n];
111 const LeafNodeType* rhsNodePt = rhsAcc.probeConstLeaf(lhsNode.origin());
112 if (!rhsNodePt) continue;
113
114 auto* const data = lhsNode.buffer().data();
115 for (Iterator it = lhsNode.beginValueOn(); it; ++it) {
116 ValueType& val = data[it.pos()];
117 val = std::min(val, offset + rhsNodePt->getValue(it.pos()));
118 }
119 }
120 }
121
122 private:
123 std::vector<LeafNodeType*>& mLhsNodes;
124 const TreeType& mRhsTree;
125 const ValueType mOffset;
126}; // struct OffsetAndMinComp
127
128
129 template<typename GridType, typename InterrupterType>
130 inline void
131normalizeLevelSet(GridType& grid, const int halfWidthInVoxels, InterrupterType* interrupt = nullptr)
132{
133 LevelSetFilter<GridType, GridType, InterrupterType> filter(grid, interrupt);
134 filter.setSpatialScheme(math::FIRST_BIAS);
135 filter.setNormCount(halfWidthInVoxels);
136 filter.normalize();
137 filter.prune();
138}
139
140
141 template<typename GridType, typename InterrupterType>
142 inline void
143smoothLevelSet(GridType& grid, int iterations, int halfBandWidthInVoxels,
144 InterrupterType* interrupt = nullptr)
145{
146 using ValueType = typename GridType::ValueType;
147 using TreeType = typename GridType::TreeType;
148 using LeafNodeType = typename TreeType::LeafNodeType;
149
150 GridType filterGrid(grid);
151
152 LevelSetFilter<GridType, GridType, InterrupterType> filter(filterGrid, interrupt);
153 filter.setSpatialScheme(math::FIRST_BIAS);
154
155 for (int n = 0; n < iterations; ++n) {
156 if (interrupt && interrupt->wasInterrupted()) break;
157 filter.mean(1);
158 }
159
160 std::vector<LeafNodeType*> nodes;
161 grid.tree().getNodes(nodes);
162
163 const ValueType offset = ValueType(double(0.5) * grid.transform().voxelSize()[0]);
164
165 tbb::parallel_for(tbb::blocked_range<size_t>(0, nodes.size()),
166 OffsetAndMinComp<TreeType>(nodes, filterGrid.tree(), -offset));
167
168 // Clean up any damanage that was done by the min operation
169 normalizeLevelSet(grid, halfBandWidthInVoxels, interrupt);
170}
171
172} // namespace ttls_internal
173
174/// @endcond
175
176 template<typename GridT, typename InterrupterT>
177 typename GridT::template ValueConverter<float>::Type::Ptr
178 topologyToLevelSet(const GridT& grid, int halfWidth, int closingSteps, int dilation,
179 int smoothingSteps, InterrupterT* interrupt)
180{
181 using MaskTreeT = typename GridT::TreeType::template ValueConverter<ValueMask>::Type;
182 using FloatTreeT = typename GridT::TreeType::template ValueConverter<float>::Type;
183 using FloatGridT = Grid<FloatTreeT>;
184
185 // Check inputs
186
187 halfWidth = std::max(halfWidth, 1);
188 closingSteps = std::max(closingSteps, 0);
189 dilation = std::max(dilation, 0);
190
191 if (!grid.hasUniformVoxels()) {
192 OPENVDB_THROW(ValueError, "Non-uniform voxels are not supported!");
193 }
194
195 // Copy the topology into a MaskGrid.
196 MaskTreeT maskTree(grid.tree(), false/*background*/, openvdb::TopologyCopy());
197
198 // Morphological closing operation.
199 tools::dilateActiveValues(maskTree, closingSteps + dilation, tools::NN_FACE, tools::PRESERVE_TILES);
200 tools::erodeActiveValues(maskTree, /*iterations=*/closingSteps, tools::NN_FACE, tools::PRESERVE_TILES);
201 tools::pruneInactive(maskTree);
202
203 // Generate a volume with an implicit zero crossing at the boundary
204 // between active and inactive values in the input grid.
205 const float background = float(grid.voxelSize()[0]) * float(halfWidth);
206 typename FloatTreeT::Ptr lsTree(
207 new FloatTreeT(maskTree, /*out=*/background, /*in=*/-background, openvdb::TopologyCopy()));
208
209 tbb::task_group pool;
210 pool.run([&]() {
211 tools::erodeActiveValues(maskTree, /*iterations=*/halfWidth, tools::NN_FACE, tools::PRESERVE_TILES);
212 tools::pruneInactive(maskTree);
213 });
214 pool.run([&]() {
215 tools::dilateActiveValues(*lsTree, /*iterations=*/halfWidth, tools::NN_FACE, tools::PRESERVE_TILES);
216 });
217 pool.wait();// wait for both tasks to complete
218
219 lsTree->topologyDifference(maskTree);
220 maskTree.clear();
221
222 lsTree->voxelizeActiveTiles(); // has to come before ::pruneLevelSet
223 tools::pruneLevelSet(*lsTree, /*threading=*/true);
224
225 // Create a level set grid from the tree
226 typename FloatGridT::Ptr lsGrid = FloatGridT::create(lsTree);
227 lsGrid->setTransform(grid.transform().copy());
228 lsGrid->setGridClass(openvdb::GRID_LEVEL_SET);
229
230 // Use a PDE based scheme to propagate distance values from the
231 // implicit zero crossing.
232 ttls_internal::normalizeLevelSet(*lsGrid, 3*halfWidth, interrupt);
233
234 // Additional filtering
235 if (smoothingSteps > 0) {
236 ttls_internal::smoothLevelSet(*lsGrid, smoothingSteps, halfWidth, interrupt);
237 }
238
239 return lsGrid;
240}
241
242
243 template<typename GridT>
244 typename GridT::template ValueConverter<float>::Type::Ptr
245 topologyToLevelSet(const GridT& grid, int halfWidth, int closingSteps, int dilation, int smoothingSteps)
246{
247 util::NullInterrupter interrupt;
248 return topologyToLevelSet(grid, halfWidth, closingSteps, dilation, smoothingSteps, &interrupt);
249}
250
251
252////////////////////////////////////////
253
254
255// Explicit Template Instantiation
256
257#ifdef OPENVDB_USE_EXPLICIT_INSTANTIATION
258
259#ifdef OPENVDB_INSTANTIATE_TOPOLOGYTOLEVELSET
260#include <openvdb/util/ExplicitInstantiation.h>
261#endif
262
263#define _FUNCTION(TreeT) \
264 Grid<TreeT>::ValueConverter<float>::Type::Ptr topologyToLevelSet(const Grid<TreeT>&, int, int, int, int, \
265 util::NullInterrupter*)
266 OPENVDB_ALL_TREE_INSTANTIATE(_FUNCTION)
267#undef _FUNCTION
268
269#endif // OPENVDB_USE_EXPLICIT_INSTANTIATION
270
271
272} // namespace tools
273} // namespace OPENVDB_VERSION_NAME
274} // namespace openvdb
275
276#endif // OPENVDB_TOOLS_TOPOLOGY_TO_LEVELSET_HAS_BEEN_INCLUDED
277
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...
openvdb::v13_0::Grid
Container class that associates a tree with a transform and metadata.
Definition Grid.h:571
openvdb::v13_0::TopologyCopy
Tag dispatch class that distinguishes topology copy constructors from deep copy constructors.
Definition Types.h:750
openvdb::v13_0::ValueError
Definition Exceptions.h:65
nanovdb::GridType
GridType
List of types that are currently supported by NanoVDB.
Definition NanoVDB.h:214
openvdb::v13_0::tools::NN_FACE
@ NN_FACE
Definition Morphology.h:60
openvdb::v13_0::tools::pruneLevelSet
void pruneLevelSet(TreeT &tree, bool threaded=true, size_t grainSize=1)
Reduce the memory footprint of a tree by replacing nodes whose values are all inactive with inactive ...
Definition Prune.h:390
openvdb::v13_0::tools::erodeActiveValues
void erodeActiveValues(TreeOrLeafManagerT &tree, const int iterations=1, const NearestNeighbors nn=NN_FACE, const TilePolicy mode=PRESERVE_TILES, const bool threaded=true)
Topologically erode all active values (i.e. both voxels and tiles) in a tree using one of three neare...
Definition Morphology.h:1134
openvdb::v13_0::tools::dilateActiveValues
void dilateActiveValues(TreeOrLeafManagerT &tree, const int iterations=1, const NearestNeighbors nn=NN_FACE, const TilePolicy mode=PRESERVE_TILES, const bool threaded=true)
Topologically dilate all active values (i.e. both voxels and tiles) in a tree using one of three near...
Definition Morphology.h:1057
openvdb::v13_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::v13_0::tools::PRESERVE_TILES
@ PRESERVE_TILES
Definition Morphology.h:82
openvdb::v13_0::tools::pruneInactive
void pruneInactive(TreeT &tree, bool threaded=true, size_t grainSize=1)
Reduce the memory footprint of a tree by replacing with background tiles any nodes whose values are a...
Definition Prune.h:355
openvdb::v13_0::GRID_LEVEL_SET
@ GRID_LEVEL_SET
Definition Types.h:522
openvdb
Definition Exceptions.h:13
OPENVDB_THROW
#define OPENVDB_THROW(exception, message)
Definition Exceptions.h:74
Types.h
openvdb.h
openvdb::v13_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:218
OPENVDB_ALL_TREE_INSTANTIATE
#define OPENVDB_ALL_TREE_INSTANTIATE(Function)
Definition version.h.in:166