OpenVDB 12.1.0

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VolumeToSpheres.h
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1// Copyright Contributors to the OpenVDB Project
2// SPDX-License-Identifier: Apache-2.0
3
4/// @file tools/VolumeToSpheres.h
5///
6/// @brief Fill a closed level set or fog volume with adaptively-sized spheres.
7
8#ifndef OPENVDB_TOOLS_VOLUME_TO_SPHERES_HAS_BEEN_INCLUDED
9#define OPENVDB_TOOLS_VOLUME_TO_SPHERES_HAS_BEEN_INCLUDED
10
11#include <openvdb/tree/LeafManager.h>
12#include <openvdb/math/Math.h>
13#include "Morphology.h" // for erodeActiveValues()
14#include "PointScatter.h"
15#include "LevelSetRebuild.h"
16#include "LevelSetUtil.h"
17#include "VolumeToMesh.h"
18#include <openvdb/openvdb.h>
19
20#include <tbb/blocked_range.h>
21#include <tbb/parallel_for.h>
22#include <tbb/parallel_reduce.h>
23
24#include <algorithm> // for std::min(), std::max()
25#include <cmath> // for std::sqrt()
26#include <limits> // for std::numeric_limits
27#include <memory>
28#include <random>
29#include <utility> // for std::pair
30#include <vector>
31
32
33 namespace openvdb {
34 OPENVDB_USE_VERSION_NAMESPACE
35 namespace OPENVDB_VERSION_NAME {
36 namespace tools {
37
38/// @brief Fill a closed level set or fog volume with adaptively-sized spheres.
39///
40/// @param grid a scalar grid that defines the surface to be filled with spheres
41/// @param spheres an output array of 4-tuples representing the fitted spheres<BR>
42/// The first three components of each tuple specify the sphere center,
43/// and the fourth specifies the radius.
44/// The spheres are ordered by radius, from largest to smallest.
45/// @param sphereCount lower and upper bounds on the number of spheres to be generated<BR>
46/// The actual number will be somewhere within the bounds.
47/// @param overlapping toggle to allow spheres to overlap/intersect
48/// @param minRadius the smallest allowable sphere size, in voxel units<BR>
49/// @param maxRadius the largest allowable sphere size, in voxel units
50/// @param isovalue the voxel value that determines the surface of the volume<BR>
51/// The default value of zero works for signed distance fields,
52/// while fog volumes require a larger positive value
53/// (0.5 is a good initial guess).
54/// @param instanceCount the number of interior points to consider for the sphere placement<BR>
55/// Increasing this count increases the chances of finding optimal
56/// sphere sizes.
57/// @param interrupter pointer to an object adhering to the util::NullInterrupter interface
58///
59/// @note The minimum sphere count takes precedence over the minimum radius.
60 template<typename GridT, typename InterrupterT = util::NullInterrupter>
61 void
62 fillWithSpheres(
63 const GridT& grid,
64 std::vector<openvdb::Vec4s>& spheres,
65 const Vec2i& sphereCount = Vec2i(1, 50),
66 bool overlapping = false,
67 float minRadius = 1.0,
68 float maxRadius = std::numeric_limits<float>::max(),
69 float isovalue = 0.0,
70 int instanceCount = 10000,
71 InterrupterT* interrupter = nullptr);
72
73
74////////////////////////////////////////
75
76
77/// @brief Accelerated closest surface point queries for narrow band level sets
78/// @details Supports queries that originate at arbitrary world-space locations,
79/// is not confined to the narrow band region of the input volume geometry.
80 template<typename GridT>
81 class ClosestSurfacePoint
82{
83 public:
84 using Ptr = std::unique_ptr<ClosestSurfacePoint>;
85 using TreeT = typename GridT::TreeType;
86 using BoolTreeT = typename TreeT::template ValueConverter<bool>::Type;
87 using Index32TreeT = typename TreeT::template ValueConverter<Index32>::Type;
88 using Int16TreeT = typename TreeT::template ValueConverter<Int16>::Type;
89
90 /// @brief Extract surface points and construct a spatial acceleration structure.
91 ///
92 /// @return a null pointer if the initialization fails for any reason,
93 /// otherwise a unique pointer to a newly-allocated ClosestSurfacePoint object.
94 ///
95 /// @param grid a scalar level set or fog volume
96 /// @param isovalue the voxel value that determines the surface of the volume
97 /// The default value of zero works for signed distance fields,
98 /// while fog volumes require a larger positive value
99 /// (0.5 is a good initial guess).
100 /// @param interrupter pointer to an object adhering to the util::NullInterrupter interface.
101 template<typename InterrupterT = util::NullInterrupter>
102 static Ptr create(const GridT& grid, float isovalue = 0.0,
103 InterrupterT* interrupter = nullptr);
104
105 /// @brief Compute the distance from each input point to its closest surface point.
106 /// @param points input list of points in world space
107 /// @param distances output list of closest surface point distances
108 bool search(const std::vector<Vec3R>& points, std::vector<float>& distances);
109
110 /// @brief Overwrite each input point with its closest surface point.
111 /// @param points input/output list of points in world space
112 /// @param distances output list of closest surface point distances
113 bool searchAndReplace(std::vector<Vec3R>& points, std::vector<float>& distances);
114
115 /// @brief Tree accessor
116 const Index32TreeT& indexTree() const { return *mIdxTreePt; }
117 /// @brief Tree accessor
118 const Int16TreeT& signTree() const { return *mSignTreePt; }
119
120 private:
121 using Index32LeafT = typename Index32TreeT::LeafNodeType;
122 using IndexRange = std::pair<size_t, size_t>;
123
124 std::vector<Vec4R> mLeafBoundingSpheres, mNodeBoundingSpheres;
125 std::vector<IndexRange> mLeafRanges;
126 std::vector<const Index32LeafT*> mLeafNodes;
127 PointList mSurfacePointList;
128 size_t mPointListSize = 0, mMaxNodeLeafs = 0;
129 typename Index32TreeT::Ptr mIdxTreePt;
130 typename Int16TreeT::Ptr mSignTreePt;
131
132 ClosestSurfacePoint() = default;
133 template<typename InterrupterT = util::NullInterrupter>
134 bool initialize(const GridT&, float isovalue, InterrupterT*);
135 bool search(std::vector<Vec3R>&, std::vector<float>&, bool transformPoints);
136};
137
138
139////////////////////////////////////////
140
141
142// Internal utility methods
143
144/// @cond OPENVDB_DOCS_INTERNAL
145
146 namespace v2s_internal {
147
148 struct PointAccessor
149{
150 PointAccessor(std::vector<Vec3R>& points)
151 : mPoints(points)
152 {
153 }
154
155 void add(const Vec3R &pos)
156 {
157 mPoints.push_back(pos);
158 }
159 private:
160 std::vector<Vec3R>& mPoints;
161};
162
163
164 template<typename Index32LeafT>
165 class LeafOp
166{
167 public:
168
169 LeafOp(std::vector<Vec4R>& leafBoundingSpheres,
170 const std::vector<const Index32LeafT*>& leafNodes,
171 const math::Transform& transform,
172 const PointList& surfacePointList);
173
174 void run(bool threaded = true);
175
176
177 void operator()(const tbb::blocked_range<size_t>&) const;
178
179 private:
180 std::vector<Vec4R>& mLeafBoundingSpheres;
181 const std::vector<const Index32LeafT*>& mLeafNodes;
182 const math::Transform& mTransform;
183 const PointList& mSurfacePointList;
184};
185
186 template<typename Index32LeafT>
187LeafOp<Index32LeafT>::LeafOp(
188 std::vector<Vec4R>& leafBoundingSpheres,
189 const std::vector<const Index32LeafT*>& leafNodes,
190 const math::Transform& transform,
191 const PointList& surfacePointList)
192 : mLeafBoundingSpheres(leafBoundingSpheres)
193 , mLeafNodes(leafNodes)
194 , mTransform(transform)
195 , mSurfacePointList(surfacePointList)
196{
197}
198
199 template<typename Index32LeafT>
200 void
201LeafOp<Index32LeafT>::run(bool threaded)
202{
203 if (threaded) {
204 tbb::parallel_for(tbb::blocked_range<size_t>(0, mLeafNodes.size()), *this);
205 } else {
206 (*this)(tbb::blocked_range<size_t>(0, mLeafNodes.size()));
207 }
208}
209
210 template<typename Index32LeafT>
211 void
212LeafOp<Index32LeafT>::operator()(const tbb::blocked_range<size_t>& range) const
213{
214 typename Index32LeafT::ValueOnCIter iter;
215 Vec3s avg;
216
217 for (size_t n = range.begin(); n != range.end(); ++n) {
218 avg[0] = 0.0;
219 avg[1] = 0.0;
220 avg[2] = 0.0;
221
222 int count = 0;
223 for (iter = mLeafNodes[n]->cbeginValueOn(); iter; ++iter) {
224 avg += mSurfacePointList[iter.getValue()];
225 ++count;
226 }
227 if (count > 1) avg *= float(1.0 / double(count));
228
229 float maxDist = 0.0;
230 for (iter = mLeafNodes[n]->cbeginValueOn(); iter; ++iter) {
231 float tmpDist = (mSurfacePointList[iter.getValue()] - avg).lengthSqr();
232 if (tmpDist > maxDist) maxDist = tmpDist;
233 }
234
235 Vec4R& sphere = mLeafBoundingSpheres[n];
236 sphere[0] = avg[0];
237 sphere[1] = avg[1];
238 sphere[2] = avg[2];
239 sphere[3] = maxDist * 2.0; // padded radius
240 }
241}
242
243
244 class NodeOp
245{
246 public:
247 using IndexRange = std::pair<size_t, size_t>;
248
249 NodeOp(std::vector<Vec4R>& nodeBoundingSpheres,
250 const std::vector<IndexRange>& leafRanges,
251 const std::vector<Vec4R>& leafBoundingSpheres);
252
253 inline void run(bool threaded = true);
254
255 inline void operator()(const tbb::blocked_range<size_t>&) const;
256
257 private:
258 std::vector<Vec4R>& mNodeBoundingSpheres;
259 const std::vector<IndexRange>& mLeafRanges;
260 const std::vector<Vec4R>& mLeafBoundingSpheres;
261};
262
263 inline
264NodeOp::NodeOp(std::vector<Vec4R>& nodeBoundingSpheres,
265 const std::vector<IndexRange>& leafRanges,
266 const std::vector<Vec4R>& leafBoundingSpheres)
267 : mNodeBoundingSpheres(nodeBoundingSpheres)
268 , mLeafRanges(leafRanges)
269 , mLeafBoundingSpheres(leafBoundingSpheres)
270{
271}
272
273 inline void
274NodeOp::run(bool threaded)
275{
276 if (threaded) {
277 tbb::parallel_for(tbb::blocked_range<size_t>(0, mLeafRanges.size()), *this);
278 } else {
279 (*this)(tbb::blocked_range<size_t>(0, mLeafRanges.size()));
280 }
281}
282
283 inline void
284NodeOp::operator()(const tbb::blocked_range<size_t>& range) const
285{
286 Vec3d avg, pos;
287
288 for (size_t n = range.begin(); n != range.end(); ++n) {
289
290 avg[0] = 0.0;
291 avg[1] = 0.0;
292 avg[2] = 0.0;
293
294 int count = int(mLeafRanges[n].second) - int(mLeafRanges[n].first);
295
296 for (size_t i = mLeafRanges[n].first; i < mLeafRanges[n].second; ++i) {
297 avg[0] += mLeafBoundingSpheres[i][0];
298 avg[1] += mLeafBoundingSpheres[i][1];
299 avg[2] += mLeafBoundingSpheres[i][2];
300 }
301
302 if (count > 1) avg *= float(1.0 / double(count));
303
304
305 double maxDist = 0.0;
306
307 for (size_t i = mLeafRanges[n].first; i < mLeafRanges[n].second; ++i) {
308 pos[0] = mLeafBoundingSpheres[i][0];
309 pos[1] = mLeafBoundingSpheres[i][1];
310 pos[2] = mLeafBoundingSpheres[i][2];
311 const auto radiusSqr = mLeafBoundingSpheres[i][3];
312
313 double tmpDist = (pos - avg).lengthSqr() + radiusSqr;
314 if (tmpDist > maxDist) maxDist = tmpDist;
315 }
316
317 Vec4R& sphere = mNodeBoundingSpheres[n];
318
319 sphere[0] = avg[0];
320 sphere[1] = avg[1];
321 sphere[2] = avg[2];
322 sphere[3] = maxDist * 2.0; // padded radius
323 }
324}
325
326
327////////////////////////////////////////
328
329
330 template<typename Index32LeafT>
331 class ClosestPointDist
332{
333 public:
334 using IndexRange = std::pair<size_t, size_t>;
335
336 ClosestPointDist(
337 std::vector<Vec3R>& instancePoints,
338 std::vector<float>& instanceDistances,
339 const PointList& surfacePointList,
340 const std::vector<const Index32LeafT*>& leafNodes,
341 const std::vector<IndexRange>& leafRanges,
342 const std::vector<Vec4R>& leafBoundingSpheres,
343 const std::vector<Vec4R>& nodeBoundingSpheres,
344 size_t maxNodeLeafs,
345 bool transformPoints = false);
346
347
348 void run(bool threaded = true);
349
350
351 void operator()(const tbb::blocked_range<size_t>&) const;
352
353 private:
354
355 void evalLeaf(size_t index, const Index32LeafT& leaf) const;
356 void evalNode(size_t pointIndex, size_t nodeIndex) const;
357
358
359 std::vector<Vec3R>& mInstancePoints;
360 std::vector<float>& mInstanceDistances;
361
362 const PointList& mSurfacePointList;
363
364 const std::vector<const Index32LeafT*>& mLeafNodes;
365 const std::vector<IndexRange>& mLeafRanges;
366 const std::vector<Vec4R>& mLeafBoundingSpheres;
367 const std::vector<Vec4R>& mNodeBoundingSpheres;
368
369 std::vector<float> mLeafDistances, mNodeDistances;
370
371 const bool mTransformPoints;
372 size_t mClosestPointIndex;
373};// ClosestPointDist
374
375
376 template<typename Index32LeafT>
377ClosestPointDist<Index32LeafT>::ClosestPointDist(
378 std::vector<Vec3R>& instancePoints,
379 std::vector<float>& instanceDistances,
380 const PointList& surfacePointList,
381 const std::vector<const Index32LeafT*>& leafNodes,
382 const std::vector<IndexRange>& leafRanges,
383 const std::vector<Vec4R>& leafBoundingSpheres,
384 const std::vector<Vec4R>& nodeBoundingSpheres,
385 size_t maxNodeLeafs,
386 bool transformPoints)
387 : mInstancePoints(instancePoints)
388 , mInstanceDistances(instanceDistances)
389 , mSurfacePointList(surfacePointList)
390 , mLeafNodes(leafNodes)
391 , mLeafRanges(leafRanges)
392 , mLeafBoundingSpheres(leafBoundingSpheres)
393 , mNodeBoundingSpheres(nodeBoundingSpheres)
394 , mLeafDistances(maxNodeLeafs, 0.0)
395 , mNodeDistances(leafRanges.size(), 0.0)
396 , mTransformPoints(transformPoints)
397 , mClosestPointIndex(0)
398{
399}
400
401
402 template<typename Index32LeafT>
403 void
404ClosestPointDist<Index32LeafT>::run(bool threaded)
405{
406 if (threaded) {
407 tbb::parallel_for(tbb::blocked_range<size_t>(0, mInstancePoints.size()), *this);
408 } else {
409 (*this)(tbb::blocked_range<size_t>(0, mInstancePoints.size()));
410 }
411}
412
413 template<typename Index32LeafT>
414 void
415ClosestPointDist<Index32LeafT>::evalLeaf(size_t index, const Index32LeafT& leaf) const
416{
417 typename Index32LeafT::ValueOnCIter iter;
418 const Vec3s center = mInstancePoints[index];
419 size_t& closestPointIndex = const_cast<size_t&>(mClosestPointIndex);
420
421 for (iter = leaf.cbeginValueOn(); iter; ++iter) {
422
423 const Vec3s& point = mSurfacePointList[iter.getValue()];
424 float tmpDist = (point - center).lengthSqr();
425
426 if (tmpDist < mInstanceDistances[index]) {
427 mInstanceDistances[index] = tmpDist;
428 closestPointIndex = iter.getValue();
429 }
430 }
431}
432
433
434 template<typename Index32LeafT>
435 void
436ClosestPointDist<Index32LeafT>::evalNode(size_t pointIndex, size_t nodeIndex) const
437{
438 if (nodeIndex >= mLeafRanges.size()) return;
439
440 const Vec3R& pos = mInstancePoints[pointIndex];
441 float minDist = mInstanceDistances[pointIndex];
442 size_t minDistIdx = 0;
443 Vec3R center;
444 bool updatedDist = false;
445
446 for (size_t i = mLeafRanges[nodeIndex].first, n = 0;
447 i < mLeafRanges[nodeIndex].second; ++i, ++n)
448 {
449 float& distToLeaf = const_cast<float&>(mLeafDistances[n]);
450
451 center[0] = mLeafBoundingSpheres[i][0];
452 center[1] = mLeafBoundingSpheres[i][1];
453 center[2] = mLeafBoundingSpheres[i][2];
454 const auto radiusSqr = mLeafBoundingSpheres[i][3];
455
456 distToLeaf = float(std::max(0.0, (pos - center).lengthSqr() - radiusSqr));
457
458 if (distToLeaf < minDist) {
459 minDist = distToLeaf;
460 minDistIdx = i;
461 updatedDist = true;
462 }
463 }
464
465 if (!updatedDist) return;
466
467 evalLeaf(pointIndex, *mLeafNodes[minDistIdx]);
468
469 for (size_t i = mLeafRanges[nodeIndex].first, n = 0;
470 i < mLeafRanges[nodeIndex].second; ++i, ++n)
471 {
472 if (mLeafDistances[n] < mInstanceDistances[pointIndex] && i != minDistIdx) {
473 evalLeaf(pointIndex, *mLeafNodes[i]);
474 }
475 }
476}
477
478
479 template<typename Index32LeafT>
480 void
481ClosestPointDist<Index32LeafT>::operator()(const tbb::blocked_range<size_t>& range) const
482{
483 Vec3R center;
484 for (size_t n = range.begin(); n != range.end(); ++n) {
485
486 const Vec3R& pos = mInstancePoints[n];
487 float minDist = mInstanceDistances[n];
488 size_t minDistIdx = 0;
489
490 for (size_t i = 0, I = mNodeDistances.size(); i < I; ++i) {
491 float& distToNode = const_cast<float&>(mNodeDistances[i]);
492
493 center[0] = mNodeBoundingSpheres[i][0];
494 center[1] = mNodeBoundingSpheres[i][1];
495 center[2] = mNodeBoundingSpheres[i][2];
496 const auto radiusSqr = mNodeBoundingSpheres[i][3];
497
498 distToNode = float(std::max(0.0, (pos - center).lengthSqr() - radiusSqr));
499
500 if (distToNode < minDist) {
501 minDist = distToNode;
502 minDistIdx = i;
503 }
504 }
505
506 evalNode(n, minDistIdx);
507
508 for (size_t i = 0, I = mNodeDistances.size(); i < I; ++i) {
509 if (mNodeDistances[i] < mInstanceDistances[n] && i != minDistIdx) {
510 evalNode(n, i);
511 }
512 }
513
514 mInstanceDistances[n] = std::sqrt(mInstanceDistances[n]);
515
516 if (mTransformPoints) mInstancePoints[n] = mSurfacePointList[mClosestPointIndex];
517 }
518}
519
520
521 class UpdatePoints
522{
523 public:
524 UpdatePoints(
525 const Vec4s& sphere,
526 const std::vector<Vec3R>& points,
527 std::vector<float>& distances,
528 std::vector<unsigned char>& mask,
529 bool overlapping);
530
531 float radius() const { return mRadius; }
532 int index() const { return mIndex; }
533
534 inline void run(bool threaded = true);
535
536
537 UpdatePoints(UpdatePoints&, tbb::split);
538 inline void operator()(const tbb::blocked_range<size_t>& range);
539 void join(const UpdatePoints& rhs)
540 {
541 if (rhs.mRadius > mRadius) {
542 mRadius = rhs.mRadius;
543 mIndex = rhs.mIndex;
544 }
545 }
546
547 private:
548 const Vec4s& mSphere;
549 const std::vector<Vec3R>& mPoints;
550 std::vector<float>& mDistances;
551 std::vector<unsigned char>& mMask;
552 const bool mOverlapping;
553 float mRadius;
554 int mIndex;
555};
556
557 inline
558UpdatePoints::UpdatePoints(
559 const Vec4s& sphere,
560 const std::vector<Vec3R>& points,
561 std::vector<float>& distances,
562 std::vector<unsigned char>& mask,
563 bool overlapping)
564 : mSphere(sphere)
565 , mPoints(points)
566 , mDistances(distances)
567 , mMask(mask)
568 , mOverlapping(overlapping)
569 , mRadius(0.0)
570 , mIndex(0)
571{
572}
573
574 inline
575UpdatePoints::UpdatePoints(UpdatePoints& rhs, tbb::split)
576 : mSphere(rhs.mSphere)
577 , mPoints(rhs.mPoints)
578 , mDistances(rhs.mDistances)
579 , mMask(rhs.mMask)
580 , mOverlapping(rhs.mOverlapping)
581 , mRadius(0.0)
582 , mIndex(0)
583{
584}
585
586 inline void
587UpdatePoints::run(bool threaded)
588{
589 if (threaded) {
590 tbb::parallel_reduce(tbb::blocked_range<size_t>(0, mPoints.size()), *this);
591 } else {
592 (*this)(tbb::blocked_range<size_t>(0, mPoints.size()));
593 }
594}
595
596 inline void
597UpdatePoints::operator()(const tbb::blocked_range<size_t>& range)
598{
599 Vec3s pos;
600 for (size_t n = range.begin(); n != range.end(); ++n) {
601 if (mMask[n]) continue;
602
603 pos.x() = float(mPoints[n].x()) - mSphere[0];
604 pos.y() = float(mPoints[n].y()) - mSphere[1];
605 pos.z() = float(mPoints[n].z()) - mSphere[2];
606
607 float dist = pos.length();
608
609 if (dist < mSphere[3]) {
610 mMask[n] = 1;
611 continue;
612 }
613
614 if (!mOverlapping) {
615 mDistances[n] = std::min(mDistances[n], (dist - mSphere[3]));
616 }
617
618 if (mDistances[n] > mRadius) {
619 mRadius = mDistances[n];
620 mIndex = int(n);
621 }
622 }
623}
624
625
626} // namespace v2s_internal
627
628/// @endcond
629
630////////////////////////////////////////
631
632
633 template<typename GridT, typename InterrupterT>
634 void
635 fillWithSpheres(
636 const GridT& grid,
637 std::vector<openvdb::Vec4s>& spheres,
638 const Vec2i& sphereCount,
639 bool overlapping,
640 float minRadius,
641 float maxRadius,
642 float isovalue,
643 int instanceCount,
644 InterrupterT* interrupter)
645{
646 spheres.clear();
647
648 if (grid.empty()) return;
649
650 const int
651 minSphereCount = sphereCount[0],
652 maxSphereCount = sphereCount[1];
653 if ((minSphereCount > maxSphereCount) || (maxSphereCount < 1)) {
654 OPENVDB_LOG_WARN("fillWithSpheres: minimum sphere count ("
655 << minSphereCount << ") exceeds maximum count (" << maxSphereCount << ")");
656 return;
657 }
658 spheres.reserve(maxSphereCount);
659
660 auto gridPtr = grid.copy(); // shallow copy
661
662 if (gridPtr->getGridClass() == GRID_LEVEL_SET) {
663 // Clamp the isovalue to the level set's background value minus epsilon.
664 // (In a valid narrow-band level set, all voxels, including background voxels,
665 // have values less than or equal to the background value, so an isovalue
666 // greater than or equal to the background value would produce a mask with
667 // effectively infinite extent.)
668 isovalue = std::min(isovalue,
669 static_cast<float>(gridPtr->background() - math::Tolerance<float>::value()));
670 } else if (gridPtr->getGridClass() == GRID_FOG_VOLUME) {
671 // Clamp the isovalue of a fog volume between epsilon and one,
672 // again to avoid a mask with infinite extent. (Recall that
673 // fog volume voxel values vary from zero outside to one inside.)
674 isovalue = math::Clamp(isovalue, math::Tolerance<float>::value(), 1.f);
675 }
676
677 // ClosestSurfacePoint is inaccurate for small grids.
678 // Resample the input grid if it is too small.
679 auto numVoxels = gridPtr->activeVoxelCount();
680 if (numVoxels < 10000) {
681 const auto scale = 1.0 / math::Cbrt(2.0 * 10000.0 / double(numVoxels));
682 auto scaledXform = gridPtr->transform().copy();
683 scaledXform->preScale(scale);
684
685 auto newGridPtr = levelSetRebuild(*gridPtr, isovalue,
686 LEVEL_SET_HALF_WIDTH, LEVEL_SET_HALF_WIDTH, scaledXform.get(), interrupter);
687
688 const auto newNumVoxels = newGridPtr->activeVoxelCount();
689 if (newNumVoxels > numVoxels) {
690 OPENVDB_LOG_DEBUG_RUNTIME("fillWithSpheres: resampled input grid from "
691 << numVoxels << " voxel" << (numVoxels == 1 ? "" : "s")
692 << " to " << newNumVoxels << " voxel" << (newNumVoxels == 1 ? "" : "s"));
693 gridPtr = newGridPtr;
694 numVoxels = newNumVoxels;
695 }
696 }
697
698 const bool addNarrowBandPoints = (numVoxels < 10000);
699 int instances = std::max(instanceCount, maxSphereCount);
700
701 using TreeT = typename GridT::TreeType;
702 using BoolTreeT = typename TreeT::template ValueConverter<bool>::Type;
703 using Int16TreeT = typename TreeT::template ValueConverter<Int16>::Type;
704
705 using RandGen = std::mersenne_twister_engine<uint32_t, 32, 351, 175, 19,
706 0xccab8ee7, 11, 0xffffffff, 7, 0x31b6ab00, 15, 0xffe50000, 17, 1812433253>; // mt11213b
707 RandGen mtRand(/*seed=*/0);
708
709 const TreeT& tree = gridPtr->tree();
710 math::Transform transform = gridPtr->transform();
711
712 std::vector<Vec3R> instancePoints;
713 {
714 // Compute a mask of the voxels enclosed by the isosurface.
715 typename Grid<BoolTreeT>::Ptr interiorMaskPtr;
716 if (gridPtr->getGridClass() == GRID_LEVEL_SET) {
717 interiorMaskPtr = sdfInteriorMask(*gridPtr, isovalue);
718 } else {
719 // For non-level-set grids, the interior mask comprises the active voxels.
720 interiorMaskPtr = typename Grid<BoolTreeT>::Ptr(Grid<BoolTreeT>::create(false));
721 interiorMaskPtr->setTransform(transform.copy());
722 interiorMaskPtr->tree().topologyUnion(tree);
723 }
724
725 if (interrupter && interrupter->wasInterrupted()) return;
726
727 // If the interior mask is small and eroding it results in an empty grid,
728 // use the uneroded mask instead. (But if the minimum sphere count is zero,
729 // then eroding away the mask is acceptable.)
730 if (!addNarrowBandPoints || (minSphereCount <= 0)) {
731 tools::erodeActiveValues(interiorMaskPtr->tree(), /*iterations=*/1, tools::NN_FACE, tools::IGNORE_TILES);
732 tools::pruneInactive(interiorMaskPtr->tree());
733 } else {
734 auto& maskTree = interiorMaskPtr->tree();
735 auto copyOfTree = StaticPtrCast<BoolTreeT>(maskTree.copy());
736 tools::erodeActiveValues(maskTree, /*iterations=*/1, tools::NN_FACE, tools::IGNORE_TILES);
737 tools::pruneInactive(maskTree);
738 if (maskTree.empty()) { interiorMaskPtr->setTree(copyOfTree); }
739 }
740
741 // Scatter candidate sphere centroids (instancePoints)
742 instancePoints.reserve(instances);
743 v2s_internal::PointAccessor ptnAcc(instancePoints);
744
745 const auto scatterCount = Index64(addNarrowBandPoints ? (instances / 2) : instances);
746
747 UniformPointScatter<v2s_internal::PointAccessor, RandGen, InterrupterT> scatter(
748 ptnAcc, scatterCount, mtRand, 1.0, interrupter);
749 scatter(*interiorMaskPtr);
750 }
751
752 if (interrupter && interrupter->wasInterrupted()) return;
753
754 auto csp = ClosestSurfacePoint<GridT>::create(*gridPtr, isovalue, interrupter);
755 if (!csp) return;
756
757 // Add extra instance points in the interior narrow band.
758 if (instancePoints.size() < size_t(instances)) {
759 const Int16TreeT& signTree = csp->signTree();
760 for (auto leafIt = signTree.cbeginLeaf(); leafIt; ++leafIt) {
761 for (auto it = leafIt->cbeginValueOn(); it; ++it) {
762 const int flags = int(it.getValue());
763 if (!(volume_to_mesh_internal::EDGES & flags)
764 && (volume_to_mesh_internal::INSIDE & flags))
765 {
766 instancePoints.push_back(transform.indexToWorld(it.getCoord()));
767 }
768 if (instancePoints.size() == size_t(instances)) break;
769 }
770 if (instancePoints.size() == size_t(instances)) break;
771 }
772 }
773
774 if (interrupter && interrupter->wasInterrupted()) return;
775
776 // Assign a radius to each candidate sphere. The radius is the world-space
777 // distance from the sphere's center to the closest surface point.
778 std::vector<float> instanceRadius;
779 if (!csp->search(instancePoints, instanceRadius)) return;
780
781 float largestRadius = 0.0;
782 int largestRadiusIdx = 0;
783 for (size_t n = 0, N = instancePoints.size(); n < N; ++n) {
784 if (instanceRadius[n] > largestRadius) {
785 largestRadius = instanceRadius[n];
786 largestRadiusIdx = int(n);
787 }
788 }
789
790 std::vector<unsigned char> instanceMask(instancePoints.size(), 0);
791
792 minRadius = float(minRadius * transform.voxelSize()[0]);
793 maxRadius = float(maxRadius * transform.voxelSize()[0]);
794
795 for (size_t s = 0, S = std::min(size_t(maxSphereCount), instancePoints.size()); s < S; ++s) {
796
797 if (interrupter && interrupter->wasInterrupted()) return;
798
799 largestRadius = std::min(maxRadius, largestRadius);
800
801 if ((int(s) >= minSphereCount) && (largestRadius < minRadius)) break;
802
803 const Vec4s sphere(
804 float(instancePoints[largestRadiusIdx].x()),
805 float(instancePoints[largestRadiusIdx].y()),
806 float(instancePoints[largestRadiusIdx].z()),
807 largestRadius);
808
809 spheres.push_back(sphere);
810 instanceMask[largestRadiusIdx] = 1;
811
812 v2s_internal::UpdatePoints op(
813 sphere, instancePoints, instanceRadius, instanceMask, overlapping);
814 op.run();
815
816 largestRadius = op.radius();
817 largestRadiusIdx = op.index();
818 }
819} // fillWithSpheres
820
821
822////////////////////////////////////////
823
824
825 template<typename GridT>
826 template<typename InterrupterT>
827 typename ClosestSurfacePoint<GridT>::Ptr
828 ClosestSurfacePoint<GridT>::create(const GridT& grid, float isovalue, InterrupterT* interrupter)
829{
830 auto csp = Ptr{new ClosestSurfacePoint};
831 if (!csp->initialize(grid, isovalue, interrupter)) csp.reset();
832 return csp;
833}
834
835
836 template<typename GridT>
837 template<typename InterrupterT>
838 bool
839ClosestSurfacePoint<GridT>::initialize(
840 const GridT& grid, float isovalue, InterrupterT* interrupter)
841{
842 using Index32LeafManagerT = tree::LeafManager<Index32TreeT>;
843 using ValueT = typename GridT::ValueType;
844
845 const TreeT& tree = grid.tree();
846 const math::Transform& transform = grid.transform();
847
848 { // Extract surface point cloud
849
850 BoolTreeT mask(false);
851 volume_to_mesh_internal::identifySurfaceIntersectingVoxels(mask, tree, ValueT(isovalue));
852
853 mSignTreePt.reset(new Int16TreeT(0));
854 mIdxTreePt.reset(new Index32TreeT(std::numeric_limits<Index32>::max()));
855
856
857 volume_to_mesh_internal::computeAuxiliaryData(
858 *mSignTreePt, *mIdxTreePt, mask, tree, ValueT(isovalue));
859
860 if (interrupter && interrupter->wasInterrupted()) return false;
861
862 // count unique points
863
864 using Int16LeafNodeType = typename Int16TreeT::LeafNodeType;
865 using Index32LeafNodeType = typename Index32TreeT::LeafNodeType;
866
867 std::vector<Int16LeafNodeType*> signFlagsLeafNodes;
868 mSignTreePt->getNodes(signFlagsLeafNodes);
869
870 const tbb::blocked_range<size_t> auxiliaryLeafNodeRange(0, signFlagsLeafNodes.size());
871
872 std::unique_ptr<Index32[]> leafNodeOffsets(new Index32[signFlagsLeafNodes.size()]);
873
874 tbb::parallel_for(auxiliaryLeafNodeRange,
875 volume_to_mesh_internal::LeafNodePointCount<Int16LeafNodeType::LOG2DIM>
876 (signFlagsLeafNodes, leafNodeOffsets));
877
878 {
879 Index32 pointCount = 0;
880 for (size_t n = 0, N = signFlagsLeafNodes.size(); n < N; ++n) {
881 const Index32 tmp = leafNodeOffsets[n];
882 leafNodeOffsets[n] = pointCount;
883 pointCount += tmp;
884 }
885
886 mPointListSize = size_t(pointCount);
887 mSurfacePointList.reset(new Vec3s[mPointListSize]);
888 }
889
890
891 std::vector<Index32LeafNodeType*> pointIndexLeafNodes;
892 mIdxTreePt->getNodes(pointIndexLeafNodes);
893
894 tbb::parallel_for(auxiliaryLeafNodeRange, volume_to_mesh_internal::ComputePoints<TreeT>(
895 mSurfacePointList.get(), tree, pointIndexLeafNodes,
896 signFlagsLeafNodes, leafNodeOffsets, transform, ValueT(isovalue)));
897 }
898
899 if (interrupter && interrupter->wasInterrupted()) return false;
900
901 Index32LeafManagerT idxLeafs(*mIdxTreePt);
902
903 using Index32RootNodeT = typename Index32TreeT::RootNodeType;
904 using Index32NodeChainT = typename Index32RootNodeT::NodeChainType;
905 static_assert(Index32NodeChainT::Size > 1,
906 "expected tree depth greater than one");
907 using Index32InternalNodeT = typename Index32NodeChainT::template Get<1>;
908
909 typename Index32TreeT::NodeCIter nIt = mIdxTreePt->cbeginNode();
910 nIt.setMinDepth(Index32TreeT::NodeCIter::LEAF_DEPTH - 1);
911 nIt.setMaxDepth(Index32TreeT::NodeCIter::LEAF_DEPTH - 1);
912
913 std::vector<const Index32InternalNodeT*> internalNodes;
914
915 const Index32InternalNodeT* node = nullptr;
916 for (; nIt; ++nIt) {
917 nIt.getNode(node);
918 if (node) internalNodes.push_back(node);
919 }
920
921 std::vector<IndexRange>().swap(mLeafRanges);
922 mLeafRanges.resize(internalNodes.size());
923
924 std::vector<const Index32LeafT*>().swap(mLeafNodes);
925 mLeafNodes.reserve(idxLeafs.leafCount());
926
927 typename Index32InternalNodeT::ChildOnCIter leafIt;
928 mMaxNodeLeafs = 0;
929 for (size_t n = 0, N = internalNodes.size(); n < N; ++n) {
930
931 mLeafRanges[n].first = mLeafNodes.size();
932
933 size_t leafCount = 0;
934 for (leafIt = internalNodes[n]->cbeginChildOn(); leafIt; ++leafIt) {
935 mLeafNodes.push_back(&(*leafIt));
936 ++leafCount;
937 }
938
939 mMaxNodeLeafs = std::max(leafCount, mMaxNodeLeafs);
940
941 mLeafRanges[n].second = mLeafNodes.size();
942 }
943
944 std::vector<Vec4R>().swap(mLeafBoundingSpheres);
945 mLeafBoundingSpheres.resize(mLeafNodes.size());
946
947 v2s_internal::LeafOp<Index32LeafT> leafBS(
948 mLeafBoundingSpheres, mLeafNodes, transform, mSurfacePointList);
949 leafBS.run();
950
951
952 std::vector<Vec4R>().swap(mNodeBoundingSpheres);
953 mNodeBoundingSpheres.resize(internalNodes.size());
954
955 v2s_internal::NodeOp nodeBS(mNodeBoundingSpheres, mLeafRanges, mLeafBoundingSpheres);
956 nodeBS.run();
957 return true;
958} // ClosestSurfacePoint::initialize
959
960
961 template<typename GridT>
962 bool
963ClosestSurfacePoint<GridT>::search(std::vector<Vec3R>& points,
964 std::vector<float>& distances, bool transformPoints)
965{
966 distances.clear();
967 distances.resize(points.size(), std::numeric_limits<float>::infinity());
968
969 v2s_internal::ClosestPointDist<Index32LeafT> cpd(points, distances, mSurfacePointList,
970 mLeafNodes, mLeafRanges, mLeafBoundingSpheres, mNodeBoundingSpheres,
971 mMaxNodeLeafs, transformPoints);
972
973 cpd.run();
974
975 return true;
976}
977
978
979 template<typename GridT>
980 bool
981 ClosestSurfacePoint<GridT>::search(const std::vector<Vec3R>& points, std::vector<float>& distances)
982{
983 return search(const_cast<std::vector<Vec3R>& >(points), distances, false);
984}
985
986
987 template<typename GridT>
988 bool
989 ClosestSurfacePoint<GridT>::searchAndReplace(std::vector<Vec3R>& points,
990 std::vector<float>& distances)
991{
992 return search(points, distances, true);
993}
994
995
996////////////////////////////////////////
997
998
999// Explicit Template Instantiation
1000
1001#ifdef OPENVDB_USE_EXPLICIT_INSTANTIATION
1002
1003#ifdef OPENVDB_INSTANTIATE_VOLUMETOSPHERES
1004#include <openvdb/util/ExplicitInstantiation.h>
1005#endif
1006
1007 OPENVDB_INSTANTIATE_CLASS ClosestSurfacePoint<FloatGrid>;
1008 OPENVDB_INSTANTIATE_CLASS ClosestSurfacePoint<DoubleGrid>;
1009
1010#define _FUNCTION(TreeT) \
1011 void fillWithSpheres(const Grid<TreeT>&, std::vector<openvdb::Vec4s>&, const Vec2i&, \
1012 bool, float, float, float, int, util::NullInterrupter*)
1013 OPENVDB_REAL_TREE_INSTANTIATE(_FUNCTION)
1014#undef _FUNCTION
1015
1016#endif // OPENVDB_USE_EXPLICIT_INSTANTIATION
1017
1018
1019} // namespace tools
1020} // namespace OPENVDB_VERSION_NAME
1021} // namespace openvdb
1022
1023#endif // OPENVDB_TOOLS_VOLUME_TO_MESH_HAS_BEEN_INCLUDED
ExplicitInstantiation.h
LeafManager.h
A LeafManager manages a linear array of pointers to a given tree's leaf nodes, as well as optional au...
LevelSetRebuild.h
LevelSetUtil.h
Miscellaneous utility methods that operate primarily or exclusively on level set grids.
Math.h
General-purpose arithmetic and comparison routines, most of which accept arbitrary value types (or at...
Morphology.h
Implementation of morphological dilation and erosion.
VolumeToMesh.h
Extract polygonal surfaces from scalar volumes.
openvdb::v12_1::GridBase::setTransform
void setTransform(math::Transform::Ptr)
Associate the given transform with this grid, in place of its existing transform.
Definition Grid.h:1269
openvdb::v12_1::Grid::tree
TreeType & tree()
Return a reference to this grid's tree, which might be shared with other grids.
Definition Grid.h:908
openvdb::v12_1::Grid::create
static Ptr create(const ValueType &background)
Return a new grid with the given background value.
Definition Grid.h:1352
openvdb::v12_1::Grid::setTree
void setTree(TreeBase::Ptr) override
Associate the given tree with this grid, in place of its existing tree.
Definition Grid.h:1489
openvdb::v12_1::Grid::Ptr
SharedPtr< Grid > Ptr
Definition Grid.h:573
openvdb::v12_1::math::Transform
Definition Transform.h:40
openvdb::v12_1::math::Transform::voxelSize
Vec3d voxelSize() const
Return the size of a voxel using the linear component of the map.
Definition Transform.h:93
openvdb::v12_1::math::Transform::indexToWorld
Vec3d indexToWorld(const Vec3d &xyz) const
Apply this transformation to the given coordinates.
Definition Transform.h:108
openvdb::v12_1::math::Transform::copy
Ptr copy() const
Definition Transform.h:50
openvdb::v12_1::tools::ClosestSurfacePoint
Accelerated closest surface point queries for narrow band level sets.
Definition VolumeToSpheres.h:82
openvdb::v12_1::tools::ClosestSurfacePoint::Int16TreeT
typename TreeT::template ValueConverter< Int16 >::Type Int16TreeT
Definition VolumeToSpheres.h:88
openvdb::v12_1::tools::ClosestSurfacePoint::search
bool search(const std::vector< Vec3R > &points, std::vector< float > &distances)
Compute the distance from each input point to its closest surface point.
Definition VolumeToSpheres.h:981
openvdb::v12_1::tools::ClosestSurfacePoint::Index32TreeT
typename TreeT::template ValueConverter< Index32 >::Type Index32TreeT
Definition VolumeToSpheres.h:87
openvdb::v12_1::tools::ClosestSurfacePoint::TreeT
typename GridT::TreeType TreeT
Definition VolumeToSpheres.h:85
openvdb::v12_1::tools::ClosestSurfacePoint::searchAndReplace
bool searchAndReplace(std::vector< Vec3R > &points, std::vector< float > &distances)
Overwrite each input point with its closest surface point.
Definition VolumeToSpheres.h:989
openvdb::v12_1::tools::ClosestSurfacePoint::BoolTreeT
typename TreeT::template ValueConverter< bool >::Type BoolTreeT
Definition VolumeToSpheres.h:86
openvdb::v12_1::tools::ClosestSurfacePoint::indexTree
const Index32TreeT & indexTree() const
Tree accessor.
Definition VolumeToSpheres.h:116
openvdb::v12_1::tools::ClosestSurfacePoint::create
static Ptr create(const GridT &grid, float isovalue=0.0, InterrupterT *interrupter=nullptr)
Extract surface points and construct a spatial acceleration structure.
Definition VolumeToSpheres.h:828
openvdb::v12_1::tools::ClosestSurfacePoint::Ptr
std::unique_ptr< ClosestSurfacePoint > Ptr
Definition VolumeToSpheres.h:84
openvdb::v12_1::tools::ClosestSurfacePoint::signTree
const Int16TreeT & signTree() const
Tree accessor.
Definition VolumeToSpheres.h:118
openvdb::v12_1::tools::UniformPointScatter
The two point scatters UniformPointScatter and NonUniformPointScatter depend on the following two cla...
Definition PointScatter.h:90
openvdb::v12_1::tree::LeafManager
This class manages a linear array of pointers to a given tree's leaf nodes, as well as optional auxil...
Definition LeafManager.h:86
OPENVDB_LOG_WARN
#define OPENVDB_LOG_WARN(message)
Log a warning message of the form 'someVar << "some text" << ...'.
Definition logging.h:256
OPENVDB_LOG_DEBUG_RUNTIME
#define OPENVDB_LOG_DEBUG_RUNTIME(message)
Log a debugging message in both debug and optimized builds.
Definition logging.h:270
openvdb::v12_1::ax::run
OPENVDB_AX_API void run(const char *ax, openvdb::GridBase &grid, const AttributeBindings &bindings={})
Run a full AX pipeline (parse, compile and execute) on a single OpenVDB Grid.
openvdb::v12_1::math::Vec2i
Vec2< int32_t > Vec2i
Definition Vec2.h:530
openvdb::v12_1::math::Vec4s
Vec4< float > Vec4s
Definition Vec4.h:561
openvdb::v12_1::math::Vec3d
Vec3< double > Vec3d
Definition Vec3.h:665
openvdb::v12_1::math::Clamp
Type Clamp(Type x, Type min, Type max)
Return x clamped to [min, max].
Definition Math.h:261
openvdb::v12_1::math::Vec3s
Vec3< float > Vec3s
Definition Vec3.h:664
openvdb::v12_1::math::Cbrt
float Cbrt(float x)
Return the cube root of a floating-point value.
Definition Math.h:769
openvdb::v12_1::points
Definition AttributeArray.h:42
openvdb::v12_1::tools::NN_FACE
@ NN_FACE
Definition Morphology.h:60
openvdb::v12_1::tools::PointList
std::unique_ptr< openvdb::Vec3s[]> PointList
Point and primitive list types.
Definition VolumeToMesh.h:161
openvdb::v12_1::tools::sdfInteriorMask
GridOrTreeType::template ValueConverter< bool >::Type::Ptr sdfInteriorMask(const GridOrTreeType &volume, typename GridOrTreeType::ValueType isovalue=lsutilGridZero< GridOrTreeType >())
Threaded method to construct a boolean mask that represents interior regions in a signed distance fie...
Definition LevelSetUtil.h:2275
openvdb::v12_1::tools::op
OutGridT XformOp & op
Definition ValueTransformer.h:140
openvdb::v12_1::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::v12_1::tools::IGNORE_TILES
@ IGNORE_TILES
Definition Morphology.h:82
openvdb::v12_1::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::v12_1::tools::fillWithSpheres
void fillWithSpheres(const GridT &grid, std::vector< openvdb::Vec4s > &spheres, const Vec2i &sphereCount=Vec2i(1, 50), bool overlapping=false, float minRadius=1.0, float maxRadius=std::numeric_limits< float >::max(), float isovalue=0.0, int instanceCount=10000, InterrupterT *interrupter=nullptr)
Fill a closed level set or fog volume with adaptively-sized spheres.
Definition VolumeToSpheres.h:635
openvdb::v12_1::tools::levelSetRebuild
GridType::Ptr levelSetRebuild(const GridType &grid, float isovalue=0, float halfWidth=float(LEVEL_SET_HALF_WIDTH), const math::Transform *xform=nullptr)
Return a new grid of type GridType that contains a narrow-band level set representation of an isosurf...
Definition LevelSetRebuild.h:354
openvdb::v12_1::tools::threaded
OutGridT XformOp bool threaded
Definition ValueTransformer.h:140
openvdb::v12_1::tree
Definition PointDataGrid.h:170
openvdb::v12_1::LEVEL_SET_HALF_WIDTH
static const Real LEVEL_SET_HALF_WIDTH
Definition Types.h:532
openvdb::v12_1::GRID_FOG_VOLUME
@ GRID_FOG_VOLUME
Definition Types.h:527
openvdb::v12_1::GRID_LEVEL_SET
@ GRID_LEVEL_SET
Definition Types.h:526
openvdb::v12_1::initialize
OPENVDB_IMPORT void initialize()
Global registration of native Grid, Transform, Metadata and Point attribute types....
openvdb::v12_1::Index32
uint32_t Index32
Definition Types.h:52
openvdb::v12_1::Vec3R
math::Vec3< Real > Vec3R
Definition Types.h:72
openvdb::v12_1::Index64
uint64_t Index64
Definition Types.h:53
openvdb::v12_1::Vec4R
math::Vec4< Real > Vec4R
Definition Types.h:87
openvdb::v12_1::StaticPtrCast
SharedPtr< T > StaticPtrCast(const SharedPtr< U > &ptr)
Return a new shared pointer that points to the same object as the given pointer after a static_cast.
Definition Types.h:146
openvdb
Definition Exceptions.h:13
openvdb.h
openvdb::v12_1::math::Tolerance::value
static T value()
Definition Math.h:148
PointScatter.h
We offer three different algorithms (each in its own class) for scattering of points in active voxels...
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_INSTANTIATE_CLASS
#define OPENVDB_INSTANTIATE_CLASS
Definition version.h.in:158
OPENVDB_REAL_TREE_INSTANTIATE
#define OPENVDB_REAL_TREE_INSTANTIATE(Function)
Definition version.h.in:162