1 // Copyright Contributors to the OpenVDB Project
2 // SPDX-License-Identifier: MPL-2.0
3
4 /// @author Ken Museth
5 ///
6 /// @file tools/ParticlesToLevelSet.h
7 ///
8 /// @brief Rasterize particles with position, radius and velocity
9 /// into either a boolean mask grid or a narrow-band level set grid.
10 ///
11 /// @details Optionally, arbitrary attributes on the particles can be transferred,
12 /// resulting in additional output grids with the same topology as the main grid.
13 ///
14 /// @note Particle to level set conversion is intended to be combined with
15 /// some kind of surface postprocessing, using
16 /// @vdblink::tools::LevelSetFilter LevelSetFilter@endlink, for example.
17 /// Without such postprocessing the generated surface is typically too noisy and blobby.
18 /// However, it serves as a great and fast starting point for subsequent
19 /// level set surface processing and convolution.
20 ///
21 /// @details For particle access, any class with the following interface may be used
22 /// (see the unit test or the From Particles Houdini SOP for practical examples):
23 /// @code
24 /// struct ParticleList
25 /// {
26 /// // Return the total number of particles in the list.
27 /// // Always required!
28 /// size_t size() const;
29 ///
30 /// // Get the world-space position of the nth particle.
31 /// // Required by rasterizeSpheres().
32 /// void getPos(size_t n, Vec3R& xyz) const;
33 ///
34 /// // Get the world-space position and radius of the nth particle.
35 /// // Required by rasterizeSpheres().
36 /// void getPosRad(size_t n, Vec3R& xyz, Real& radius) const;
37 ///
38 /// // Get the world-space position, radius and velocity of the nth particle.
39 /// // Required by rasterizeTrails().
40 /// void getPosRadVel(size_t n, Vec3R& xyz, Real& radius, Vec3R& velocity) const;
41 ///
42 /// // Get the value of the nth particle's user-defined attribute (of type @c AttributeType).
43 /// // Required only if attribute transfer is enabled in ParticlesToLevelSet.
44 /// void getAtt(size_t n, AttributeType& att) const;
45 /// };
46 /// @endcode
47 ///
48 /// Some functions accept an interrupter argument. This refers to any class
49 /// with the following interface:
50 /// @code
51 /// struct Interrupter
52 /// {
53 /// void start(const char* name = nullptr) // called when computations begin
54 /// void end() // called when computations end
55 /// bool wasInterrupted(int percent=-1) // return true to abort computation
56 /// };
57 /// @endcode
58 ///
59 /// The default interrupter is @vdblink::util::NullInterrupter NullInterrupter@endlink,
60 /// for which all calls are no-ops that incur no computational overhead.
61
62 #ifndef OPENVDB_TOOLS_PARTICLES_TO_LEVELSET_HAS_BEEN_INCLUDED
63 #define OPENVDB_TOOLS_PARTICLES_TO_LEVELSET_HAS_BEEN_INCLUDED
64
65 #include "openvdb/Types.h"
66 #include "openvdb/Grid.h"
67 #include "openvdb/math/Math.h"
68 #include "openvdb/math/Transform.h"
69 #include "openvdb/tree/LeafManager.h"
70 #include "openvdb/util/logging.h"
71 #include "openvdb/util/NullInterrupter.h"
72 #include "openvdb/thread/Threading.h"
73
74 #include "Composite.h" // for csgUnion()
75 #include "PointPartitioner.h"
76 #include "Prune.h"
77 #include "SignedFloodFill.h"
78
79 #include <tbb/parallel_reduce.h>
80 #include <tbb/blocked_range.h>
81
82 #include <functional>
83 #include <iostream>
84 #include <type_traits>
85 #include <vector>
86
87
88 namespace openvdb {
89 OPENVDB_USE_VERSION_NAMESPACE
90 namespace OPENVDB_VERSION_NAME {
91 namespace tools {
92
93 /// @brief Populate a scalar, floating-point grid with CSG-unioned level set spheres
94 /// described by the given particle positions and radii.
95 /// @details For more control over the output, including attribute transfer,
96 /// use the ParticlesToLevelSet class directly.
97 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
98 inline void particlesToSdf(const ParticleListT&, GridT&, InterrupterT* = nullptr);
99
100 /// @brief Populate a scalar, floating-point grid with fixed-size, CSG-unioned
101 /// level set spheres described by the given particle positions and the specified radius.
102 /// @details For more control over the output, including attribute transfer,
103 /// use the ParticlesToLevelSet class directly.
104 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
105 inline void particlesToSdf(const ParticleListT&, GridT&, Real radius, InterrupterT* = nullptr);
106
107 /// @brief Populate a scalar, floating-point grid with CSG-unioned trails
108 /// of level set spheres with decreasing radius, where the starting position and radius
109 /// and the direction of each trail is given by particle attributes.
110 /// @details For more control over the output, including attribute transfer,
111 /// use the ParticlesToLevelSet class directly.
112 /// @note The @a delta parameter controls the distance between spheres in a trail.
113 /// Be careful not to use too small a value.
114 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
115 inline void particleTrailsToSdf(const ParticleListT&, GridT&, Real delta=1, InterrupterT* =nullptr);
116
117 /// @brief Activate a boolean grid wherever it intersects the spheres
118 /// described by the given particle positions and radii.
119 /// @details For more control over the output, including attribute transfer,
120 /// use the ParticlesToLevelSet class directly.
121 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
122 inline void particlesToMask(const ParticleListT&, GridT&, InterrupterT* = nullptr);
123
124 /// @brief Activate a boolean grid wherever it intersects the fixed-size spheres
125 /// described by the given particle positions and the specified radius.
126 /// @details For more control over the output, including attribute transfer,
127 /// use the ParticlesToLevelSet class directly.
128 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
129 inline void particlesToMask(const ParticleListT&, GridT&, Real radius, InterrupterT* = nullptr);
130
131 /// @brief Activate a boolean grid wherever it intersects trails of spheres
132 /// with decreasing radius, where the starting position and radius and the direction
133 /// of each trail is given by particle attributes.
134 /// @details For more control over the output, including attribute transfer,
135 /// use the ParticlesToLevelSet class directly.
136 /// @note The @a delta parameter controls the distance between spheres in a trail.
137 /// Be careful not to use too small a value.
138 template<typename GridT, typename ParticleListT, typename InterrupterT = util::NullInterrupter>
139 inline void particleTrailsToMask(const ParticleListT&, GridT&,Real delta=1,InterrupterT* =nullptr);
140
141
142 ////////////////////////////////////////
143
144 /// @cond OPENVDB_DOCS_INTERNAL
145
146 namespace p2ls_internal {
147 // This is a simple type that combines a distance value and a particle
148 // attribute. It's required for attribute transfer which is performed
149 // in the ParticlesToLevelSet::Raster member class defined below.
150 /// @private
151 template<typename VisibleT, typename BlindT> class BlindData;
152 }
153
154 /// @endcond
155
156 template<typename SdfGridT,
157 typename AttributeT = void,
158 typename InterrupterT = util::NullInterrupter>
159 class ParticlesToLevelSet
160 {
161 public:
162 using DisableT = typename std::is_void<AttributeT>::type;
163 using InterrupterType = InterrupterT;
164
165 using SdfGridType = SdfGridT;
166 using SdfType = typename SdfGridT::ValueType;
167
168 using AttType = typename std::conditional<DisableT::value, size_t, AttributeT>::type;
169 using AttGridType = typename SdfGridT::template ValueConverter<AttType>::Type;
170
171 static const bool OutputIsMask = std::is_same<SdfType, bool>::value;
172
173 /// @brief Constructor using an existing boolean or narrow-band level set grid
174 ///
175 /// @param grid grid into which particles are rasterized
176 /// @param interrupt callback to interrupt a long-running process
177 ///
178 /// @details If the input grid is already populated with signed distances,
179 /// particles are unioned onto the existing level set surface.
180 ///
181 /// @details The width in voxel units of the generated narrow band level set
182 /// is given by 2×<I>background</I>/<I>dx</I>, where @a background
183 /// is the background value stored in the grid and @a dx is the voxel size
184 /// derived from the transform associated with the grid.
185 /// Also note that −<I>background</I> corresponds to the constant value
186 /// inside the generated narrow-band level set.
187 ///
188 /// @note If attribute transfer is enabled, i.e., if @c AttributeT is not @c void,
189 /// attributes are generated only for voxels that overlap with particles,
190 /// not for any other preexisting voxels (for which no attributes exist!).
191 explicit ParticlesToLevelSet(SdfGridT& grid, InterrupterT* interrupt = nullptr);
192
~ParticlesToLevelSet()193 ~ParticlesToLevelSet() { delete mBlindGrid; }
194
195 /// @brief This method syncs up the level set and attribute grids
196 /// and therefore needs to be called before any of those grids are
197 /// used and after the last call to any of the rasterizer methods.
198 /// @details It has no effect or overhead if attribute transfer is disabled
199 /// (i.e., if @c AttributeT is @c void) and @a prune is @c false.
200 ///
201 /// @note Avoid calling this method more than once, and call it only after
202 /// all the particles have been rasterized.
203 void finalize(bool prune = false);
204
205 /// @brief Return a pointer to the grid containing the optional user-defined attribute.
206 /// @warning If attribute transfer is disabled (i.e., if @c AttributeT is @c void)
207 /// or if @link finalize() finalize@endlink is not called, the pointer will be null.
attributeGrid()208 typename AttGridType::Ptr attributeGrid() { return mAttGrid; }
209
210 /// @brief Return the size of a voxel in world units.
getVoxelSize()211 Real getVoxelSize() const { return mDx; }
212
213 /// @brief Return the half-width of the narrow band in voxel units.
getHalfWidth()214 Real getHalfWidth() const { return mHalfWidth; }
215
216 /// @brief Return the smallest radius allowed in voxel units.
getRmin()217 Real getRmin() const { return mRmin; }
218 /// @brief Set the smallest radius allowed in voxel units.
setRmin(Real Rmin)219 void setRmin(Real Rmin) { mRmin = math::Max(Real(0),Rmin); }
220
221 /// @brief Return the largest radius allowed in voxel units.
getRmax()222 Real getRmax() const { return mRmax; }
223 /// @brief Set the largest radius allowed in voxel units.
setRmax(Real Rmax)224 void setRmax(Real Rmax) { mRmax = math::Max(mRmin,Rmax); }
225
226 /// @brief Return @c true if any particles were ignored due to their size.
ignoredParticles()227 bool ignoredParticles() const { return mMinCount>0 || mMaxCount>0; }
228 /// @brief Return the number of particles that were ignored because they were
229 /// smaller than the minimum radius.
getMinCount()230 size_t getMinCount() const { return mMinCount; }
231 /// @brief Return the number of particles that were ignored because they were
232 /// larger than the maximum radius.
getMaxCount()233 size_t getMaxCount() const { return mMaxCount; }
234
235 /// @brief Return the grain size used for threading
getGrainSize()236 int getGrainSize() const { return mGrainSize; }
237 /// @brief Set the grain size used for threading.
238 /// @note A grain size of zero or less disables threading.
setGrainSize(int grainSize)239 void setGrainSize(int grainSize) { mGrainSize = grainSize; }
240
241 /// @brief Rasterize each particle as a sphere with the particle's position and radius.
242 /// @details For level set output, all spheres are CSG-unioned.
243 template<typename ParticleListT>
244 void rasterizeSpheres(const ParticleListT& pa);
245
246 /// @brief Rasterize each particle as a sphere with the particle's position
247 /// and a fixed radius.
248 /// @details For level set output, all spheres are CSG-unioned.
249 ///
250 /// @param pa particles with positions
251 /// @param radius fixed sphere radius in world units.
252 template<typename ParticleListT>
253 void rasterizeSpheres(const ParticleListT& pa, Real radius);
254
255 /// @brief Rasterize each particle as a trail comprising the CSG union
256 /// of spheres of decreasing radius.
257 ///
258 /// @param pa particles with position, radius and velocity.
259 /// @param delta controls the distance between sphere instances
260 ///
261 /// @warning Be careful not to use too small values for @a delta,
262 /// since this can lead to excessive computation per trail (which the
263 /// interrupter can't stop).
264 ///
265 /// @note The direction of a trail is opposite to that of the velocity vector,
266 /// and its length is given by the magnitude of the velocity.
267 /// The radius at the head of the trail is given by the radius of the particle,
268 /// and the radius at the tail is @a Rmin voxel units, which has
269 /// a default value of 1.5 corresponding to the Nyquist frequency!
270 template<typename ParticleListT>
271 void rasterizeTrails(const ParticleListT& pa, Real delta=1.0);
272
273 private:
274 using BlindType = p2ls_internal::BlindData<SdfType, AttType>;
275 using BlindGridType = typename SdfGridT::template ValueConverter<BlindType>::Type;
276
277 /// Class with multi-threaded implementation of particle rasterization
278 template<typename ParticleListT, typename GridT> struct Raster;
279
280 SdfGridType* mSdfGrid;
281 typename AttGridType::Ptr mAttGrid;
282 BlindGridType* mBlindGrid;
283 InterrupterT* mInterrupter;
284 Real mDx, mHalfWidth;
285 Real mRmin, mRmax; // ignore particles outside this range of radii in voxel
286 size_t mMinCount, mMaxCount; // counters for ignored particles
287 int mGrainSize;
288 }; // class ParticlesToLevelSet
289
290
291 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
292 inline ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::
ParticlesToLevelSet(SdfGridT & grid,InterrupterT * interrupter)293 ParticlesToLevelSet(SdfGridT& grid, InterrupterT* interrupter) :
294 mSdfGrid(&grid),
295 mBlindGrid(nullptr),
296 mInterrupter(interrupter),
297 mDx(grid.voxelSize()[0]),
298 mHalfWidth(grid.background()/mDx),
299 mRmin(1.5),// corresponds to the Nyquist grid sampling frequency
300 mRmax(100.0),// corresponds to a huge particle (probably too large!)
301 mMinCount(0),
302 mMaxCount(0),
303 mGrainSize(1)
304 {
305 if (!mSdfGrid->hasUniformVoxels()) {
306 OPENVDB_THROW(RuntimeError, "ParticlesToLevelSet only supports uniform voxels!");
307 }
308 if (!DisableT::value) {
309 mBlindGrid = new BlindGridType(BlindType(grid.background()));
310 mBlindGrid->setTransform(mSdfGrid->transform().copy());
311 }
312 }
313
314 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
315 template<typename ParticleListT>
316 inline void ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::
rasterizeSpheres(const ParticleListT & pa)317 rasterizeSpheres(const ParticleListT& pa)
318 {
319 if (DisableT::value) {
320 Raster<ParticleListT, SdfGridT> r(*this, mSdfGrid, pa);
321 r.rasterizeSpheres();
322 } else {
323 Raster<ParticleListT, BlindGridType> r(*this, mBlindGrid, pa);
324 r.rasterizeSpheres();
325 }
326 }
327
328 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
329 template<typename ParticleListT>
330 inline void ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::
rasterizeSpheres(const ParticleListT & pa,Real radius)331 rasterizeSpheres(const ParticleListT& pa, Real radius)
332 {
333 if (DisableT::value) {
334 Raster<ParticleListT, SdfGridT> r(*this, mSdfGrid, pa);
335 r.rasterizeSpheres(radius/mDx);
336 } else {
337 Raster<ParticleListT, BlindGridType> r(*this, mBlindGrid, pa);
338 r.rasterizeSpheres(radius/mDx);
339 }
340 }
341
342 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
343 template<typename ParticleListT>
344 inline void ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::
rasterizeTrails(const ParticleListT & pa,Real delta)345 rasterizeTrails(const ParticleListT& pa, Real delta)
346 {
347 if (DisableT::value) {
348 Raster<ParticleListT, SdfGridT> r(*this, mSdfGrid, pa);
349 r.rasterizeTrails(delta);
350 } else {
351 Raster<ParticleListT, BlindGridType> r(*this, mBlindGrid, pa);
352 r.rasterizeTrails(delta);
353 }
354 }
355
356
357 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
358 inline void
finalize(bool prune)359 ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::finalize(bool prune)
360 {
361 OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
362
363 if (!mBlindGrid) {
364 if (prune) {
365 if (OutputIsMask) {
366 tools::prune(mSdfGrid->tree());
367 } else {
368 tools::pruneLevelSet(mSdfGrid->tree());
369 }
370 }
371 return;
372 }
373
374 if (prune) tools::prune(mBlindGrid->tree());
375
376 using AttTreeT = typename AttGridType::TreeType;
377 using AttLeafT = typename AttTreeT::LeafNodeType;
378 using BlindTreeT = typename BlindGridType::TreeType;
379 using BlindLeafIterT = typename BlindTreeT::LeafCIter;
380 using BlindLeafT = typename BlindTreeT::LeafNodeType;
381 using SdfTreeT = typename SdfGridType::TreeType;
382 using SdfLeafT = typename SdfTreeT::LeafNodeType;
383
384 // Use topology copy constructors since output grids have the same topology as mBlindDataGrid
385 const BlindTreeT& blindTree = mBlindGrid->tree();
386
387 // Create the output attribute grid.
388 typename AttTreeT::Ptr attTree(new AttTreeT(
389 blindTree, blindTree.background().blind(), openvdb::TopologyCopy()));
390 // Note this overwrites any existing attribute grids!
391 mAttGrid = typename AttGridType::Ptr(new AttGridType(attTree));
392 mAttGrid->setTransform(mBlindGrid->transform().copy());
393
394 typename SdfTreeT::Ptr sdfTree; // the output mask or level set tree
395
396 // Extract the attribute grid and the mask or level set grid from mBlindDataGrid.
397 if (OutputIsMask) {
398 sdfTree.reset(new SdfTreeT(blindTree,
399 /*off=*/SdfType(0), /*on=*/SdfType(1), TopologyCopy()));
400
401 // Copy leaf voxels in parallel.
402 tree::LeafManager<AttTreeT> leafNodes(*attTree);
403 leafNodes.foreach([&](AttLeafT& attLeaf, size_t /*leafIndex*/) {
404 if (const auto* blindLeaf = blindTree.probeConstLeaf(attLeaf.origin())) {
405 for (auto iter = attLeaf.beginValueOn(); iter; ++iter) {
406 const auto pos = iter.pos();
407 attLeaf.setValueOnly(pos, blindLeaf->getValue(pos).blind());
408 }
409 }
410 });
411 // Copy tiles serially.
412 const auto blindAcc = mBlindGrid->getConstAccessor();
413 auto iter = attTree->beginValueOn();
414 iter.setMaxDepth(AttTreeT::ValueOnIter::LEAF_DEPTH - 1);
415 for ( ; iter; ++iter) {
416 iter.modifyValue([&](AttType& v) { v = blindAcc.getValue(iter.getCoord()).blind(); });
417 }
418 } else {
419 // Here we exploit the fact that by design level sets have no active tiles.
420 // Only leaf voxels can be active.
421 sdfTree.reset(new SdfTreeT(blindTree, blindTree.background().visible(), TopologyCopy()));
422 for (BlindLeafIterT n = blindTree.cbeginLeaf(); n; ++n) {
423 const BlindLeafT& leaf = *n;
424 const openvdb::Coord xyz = leaf.origin();
425 // Get leafnodes that were allocated during topology construction!
426 SdfLeafT* sdfLeaf = sdfTree->probeLeaf(xyz);
427 AttLeafT* attLeaf = attTree->probeLeaf(xyz);
428 // Use linear offset (vs coordinate) access for better performance!
429 typename BlindLeafT::ValueOnCIter m=leaf.cbeginValueOn();
430 if (!m) {//no active values in leaf node so copy everything
431 for (openvdb::Index k = 0; k!=BlindLeafT::SIZE; ++k) {
432 const BlindType& v = leaf.getValue(k);
433 sdfLeaf->setValueOnly(k, v.visible());
434 attLeaf->setValueOnly(k, v.blind());
435 }
436 } else {//only copy active values (using flood fill for the inactive values)
437 for(; m; ++m) {
438 const openvdb::Index k = m.pos();
439 const BlindType& v = *m;
440 sdfLeaf->setValueOnly(k, v.visible());
441 attLeaf->setValueOnly(k, v.blind());
442 }
443 }
444 }
445 tools::signedFloodFill(*sdfTree);//required since we only transferred active voxels!
446 }
447
448 if (mSdfGrid->empty()) {
449 mSdfGrid->setTree(sdfTree);
450 } else {
451 if (OutputIsMask) {
452 mSdfGrid->tree().topologyUnion(*sdfTree);
453 tools::prune(mSdfGrid->tree());
454 } else {
455 tools::csgUnion(mSdfGrid->tree(), *sdfTree, /*prune=*/true);
456 }
457 }
458
459 OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
460 }
461
462
463 ///////////////////////////////////////////////////////////
464
465
466 template<typename SdfGridT, typename AttributeT, typename InterrupterT>
467 template<typename ParticleListT, typename GridT>
468 struct ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>::Raster
469 {
470 using DisableT = typename std::is_void<AttributeT>::type;
471 using ParticlesToLevelSetT = ParticlesToLevelSet<SdfGridT, AttributeT, InterrupterT>;
472 using SdfT = typename ParticlesToLevelSetT::SdfType; // type of signed distance values
473 using AttT = typename ParticlesToLevelSetT::AttType; // type of particle attribute
474 using ValueT = typename GridT::ValueType;
475 using AccessorT = typename GridT::Accessor;
476 using TreeT = typename GridT::TreeType;
477 using LeafNodeT = typename TreeT::LeafNodeType;
478 using PointPartitionerT = PointPartitioner<Index32, LeafNodeT::LOG2DIM>;
479
480 static const bool
481 OutputIsMask = std::is_same<SdfT, bool>::value,
482 DoAttrXfer = !DisableT::value;
483
484 /// @brief Main constructor
485 Raster(ParticlesToLevelSetT& parent, GridT* grid, const ParticleListT& particles)
486 : mParent(parent)
487 , mParticles(particles)
488 , mGrid(grid)
489 , mMap(*(mGrid->transform().baseMap()))
490 , mMinCount(0)
491 , mMaxCount(0)
492 , mIsCopy(false)
493 {
494 mPointPartitioner = new PointPartitionerT;
495 mPointPartitioner->construct(particles, mGrid->transform());
496 }
497
498 /// @brief Copy constructor called by tbb threads
499 Raster(Raster& other, tbb::split)
500 : mParent(other.mParent)
501 , mParticles(other.mParticles)
502 , mGrid(new GridT(*other.mGrid, openvdb::ShallowCopy()))
503 , mMap(other.mMap)
504 , mMinCount(0)
505 , mMaxCount(0)
506 , mTask(other.mTask)
507 , mIsCopy(true)
508 , mPointPartitioner(other.mPointPartitioner)
509 {
510 mGrid->newTree();
511 }
512
513 virtual ~Raster()
514 {
515 // Copy-constructed Rasters own temporary grids that have to be deleted,
516 // while the original has ownership of the bucket array.
517 if (mIsCopy) {
518 delete mGrid;
519 } else {
520 delete mPointPartitioner;
521 }
522 }
523
524 void rasterizeSpheres()
525 {
526 mMinCount = mMaxCount = 0;
527 if (mParent.mInterrupter) {
528 mParent.mInterrupter->start("Rasterizing particles to level set using spheres");
529 }
530 mTask = std::bind(&Raster::rasterSpheres, std::placeholders::_1, std::placeholders::_2);
531 this->cook();
532 if (mParent.mInterrupter) mParent.mInterrupter->end();
533 }
534
535 void rasterizeSpheres(Real radius)
536 {
537 mMinCount = radius < mParent.mRmin ? mParticles.size() : 0;
538 mMaxCount = radius > mParent.mRmax ? mParticles.size() : 0;
539 if (mMinCount>0 || mMaxCount>0) {//skipping all particles!
540 mParent.mMinCount = mMinCount;
541 mParent.mMaxCount = mMaxCount;
542 } else {
543 if (mParent.mInterrupter) {
544 mParent.mInterrupter->start(
545 "Rasterizing particles to level set using const spheres");
546 }
547 mTask = std::bind(&Raster::rasterFixedSpheres,
548 std::placeholders::_1, std::placeholders::_2, radius);
549 this->cook();
550 if (mParent.mInterrupter) mParent.mInterrupter->end();
551 }
552 }
553
554 void rasterizeTrails(Real delta=1.0)
555 {
556 mMinCount = mMaxCount = 0;
557 if (mParent.mInterrupter) {
558 mParent.mInterrupter->start("Rasterizing particles to level set using trails");
559 }
560 mTask = std::bind(&Raster::rasterTrails,
561 std::placeholders::_1, std::placeholders::_2, delta);
562 this->cook();
563 if (mParent.mInterrupter) mParent.mInterrupter->end();
564 }
565
566 /// @brief Kick off the optionally multithreaded computation.
567 void operator()(const tbb::blocked_range<size_t>& r)
568 {
569 assert(mTask);
570 mTask(this, r);
571 mParent.mMinCount = mMinCount;
572 mParent.mMaxCount = mMaxCount;
573 }
574
575 /// @brief Required by tbb::parallel_reduce
576 void join(Raster& other)
577 {
578 OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
579 if (OutputIsMask) {
580 if (DoAttrXfer) {
581 tools::compMax(*mGrid, *other.mGrid);
582 } else {
583 mGrid->topologyUnion(*other.mGrid);
584 }
585 } else {
586 tools::csgUnion(*mGrid, *other.mGrid, /*prune=*/true);
587 }
588 OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
589 mMinCount += other.mMinCount;
590 mMaxCount += other.mMaxCount;
591 }
592
593 private:
594 /// Disallow assignment since some of the members are references
595 Raster& operator=(const Raster&) { return *this; }
596
597 /// @return true if the particle is too small or too large
598 bool ignoreParticle(Real R)
599 {
600 if (R < mParent.mRmin) {// below the cutoff radius
601 ++mMinCount;
602 return true;
603 }
604 if (R > mParent.mRmax) {// above the cutoff radius
605 ++mMaxCount;
606 return true;
607 }
608 return false;
609 }
610
611 /// @brief Threaded rasterization of particles as spheres with variable radius
612 /// @param r range of indices into the list of particles
613 void rasterSpheres(const tbb::blocked_range<size_t>& r)
614 {
615 AccessorT acc = mGrid->getAccessor(); // local accessor
616 bool run = true;
617 const Real invDx = 1 / mParent.mDx;
618 AttT att;
619 Vec3R pos;
620 Real rad;
621
622 // Loop over buckets
623 for (size_t n = r.begin(), N = r.end(); n < N; ++n) {
624 // Loop over particles in bucket n.
625 typename PointPartitionerT::IndexIterator iter = mPointPartitioner->indices(n);
626 for ( ; run && iter; ++iter) {
627 const Index32& id = *iter;
628 mParticles.getPosRad(id, pos, rad);
629 const Real R = invDx * rad;// in voxel units
630 if (this->ignoreParticle(R)) continue;
631 const Vec3R P = mMap.applyInverseMap(pos);
632 this->getAtt<DisableT>(id, att);
633 run = this->makeSphere(P, R, att, acc);
634 }//end loop over particles
635 }//end loop over buckets
636 }
637
638 /// @brief Threaded rasterization of particles as spheres with a fixed radius
639 /// @param r range of indices into the list of particles
640 /// @param R radius of fixed-size spheres
641 void rasterFixedSpheres(const tbb::blocked_range<size_t>& r, Real R)
642 {
643 AccessorT acc = mGrid->getAccessor(); // local accessor
644 AttT att;
645 Vec3R pos;
646
647 // Loop over buckets
648 for (size_t n = r.begin(), N = r.end(); n < N; ++n) {
649 // Loop over particles in bucket n.
650 for (auto iter = mPointPartitioner->indices(n); iter; ++iter) {
651 const Index32& id = *iter;
652 this->getAtt<DisableT>(id, att);
653 mParticles.getPos(id, pos);
654 const Vec3R P = mMap.applyInverseMap(pos);
655 this->makeSphere(P, R, att, acc);
656 }
657 }
658 }
659
660 /// @brief Threaded rasterization of particles as spheres with velocity trails
661 /// @param r range of indices into the list of particles
662 /// @param delta inter-sphere spacing
663 void rasterTrails(const tbb::blocked_range<size_t>& r, Real delta)
664 {
665 AccessorT acc = mGrid->getAccessor(); // local accessor
666 bool run = true;
667 AttT att;
668 Vec3R pos, vel;
669 Real rad;
670 const Vec3R origin = mMap.applyInverseMap(Vec3R(0,0,0));
671 const Real Rmin = mParent.mRmin, invDx = 1 / mParent.mDx;
672
673 // Loop over buckets
674 for (size_t n = r.begin(), N = r.end(); n < N; ++n) {
675 // Loop over particles in bucket n.
676 typename PointPartitionerT::IndexIterator iter = mPointPartitioner->indices(n);
677 for ( ; run && iter; ++iter) {
678 const Index32& id = *iter;
679 mParticles.getPosRadVel(id, pos, rad, vel);
680 const Real R0 = invDx * rad;
681 if (this->ignoreParticle(R0)) continue;
682 this->getAtt<DisableT>(id, att);
683 const Vec3R P0 = mMap.applyInverseMap(pos);
684 const Vec3R V = mMap.applyInverseMap(vel) - origin; // exclude translation
685 const Real speed = V.length(), invSpeed = 1.0 / speed;
686 const Vec3R Nrml = -V * invSpeed; // inverse normalized direction
687 Vec3R P = P0; // local position of instance
688 Real R = R0, d = 0; // local radius and length of trail
689 for (size_t m = 0; run && d <= speed ; ++m) {
690 run = this->makeSphere(P, R, att, acc);
691 P += 0.5 * delta * R * Nrml; // adaptive offset along inverse velocity direction
692 d = (P - P0).length(); // current length of trail
693 R = R0 - (R0 - Rmin) * d * invSpeed; // R = R0 -> mRmin(e.g. 1.5)
694 }//end loop over sphere instances
695 }//end loop over particles
696 }//end loop over buckets
697 }
698
699 void cook()
700 {
701 // parallelize over the point buckets
702 const Index32 bucketCount = Index32(mPointPartitioner->size());
703
704 if (mParent.mGrainSize>0) {
705 tbb::parallel_reduce(
706 tbb::blocked_range<size_t>(0, bucketCount, mParent.mGrainSize), *this);
707 } else {
708 (*this)(tbb::blocked_range<size_t>(0, bucketCount));
709 }
710 }
711
712 /// @brief Rasterize sphere at position P and radius R into
713 /// a narrow-band level set with half-width, mHalfWidth.
714 /// @return @c false if rasterization was interrupted
715 ///
716 /// @param P coordinates of the particle position in voxel units
717 /// @param R radius of particle in voxel units
718 /// @param att an optional user-defined attribute value to be associated with voxels
719 /// @param acc grid accessor with a private copy of the grid
720 ///
721 /// @note For best performance all computations are performed in voxel space,
722 /// with the important exception of the final level set value that is converted
723 /// to world units (the grid stores the closest Euclidean signed distances
724 /// measured in world units). Also note we use the convention of positive distances
725 /// outside the surface and negative distances inside the surface.
726 template <bool IsMaskT = OutputIsMask>
727 typename std::enable_if<!IsMaskT, bool>::type
728 makeSphere(const Vec3R& P, Real R, const AttT& att, AccessorT& acc)
729 {
730 const Real
731 dx = mParent.mDx,
732 w = mParent.mHalfWidth,
733 max = R + w, // maximum distance in voxel units
734 max2 = math::Pow2(max), // square of maximum distance in voxel units
735 min2 = math::Pow2(math::Max(Real(0), R - w)); // square of minimum distance
736 // Bounding box of the sphere
737 const Coord
738 lo(math::Floor(P[0]-max),math::Floor(P[1]-max),math::Floor(P[2]-max)),
739 hi(math::Ceil( P[0]+max),math::Ceil( P[1]+max),math::Ceil( P[2]+max));
740 const ValueT inside = -mGrid->background();
741
742 ValueT v;
743 size_t count = 0;
744 for (Coord c = lo; c.x() <= hi.x(); ++c.x()) {
745 //only check interrupter every 32'th scan in x
746 if (!(count++ & ((1<<5)-1)) && util::wasInterrupted(mParent.mInterrupter)) {
747 thread::cancelGroupExecution();
748 return false;
749 }
750 const Real x2 = math::Pow2(c.x() - P[0]);
751 for (c.y() = lo.y(); c.y() <= hi.y(); ++c.y()) {
752 const Real x2y2 = x2 + math::Pow2(c.y() - P[1]);
753 for (c.z() = lo.z(); c.z() <= hi.z(); ++c.z()) {
754 const Real x2y2z2 = x2y2 + math::Pow2(c.z()-P[2]); // squared dist from c to P
755 #if defined __INTEL_COMPILER
756 _Pragma("warning (push)")
757 _Pragma("warning (disable:186)") // "pointless comparison of unsigned integer with zero"
758 #endif
759 if (x2y2z2 >= max2 || (!acc.probeValue(c, v) && (v < ValueT(0))))
760 continue;//outside narrow band of the particle or inside existing level set
761 #if defined __INTEL_COMPILER
762 _Pragma("warning (pop)")
763 #endif
764 if (x2y2z2 <= min2) {//inside narrow band of the particle.
765 acc.setValueOff(c, inside);
766 continue;
767 }
768 // convert signed distance from voxel units to world units
769 //const ValueT d=dx*(math::Sqrt(x2y2z2) - R);
770 const ValueT d = Merge(static_cast<SdfT>(dx*(math::Sqrt(x2y2z2)-R)), att);
771 if (d < v) acc.setValue(c, d);//CSG union
772 }//end loop over z
773 }//end loop over y
774 }//end loop over x
775 return true;
776 }
777
778 /// @brief Rasterize a sphere of radius @a r at position @a p into a boolean mask grid.
779 /// @return @c false if rasterization was interrupted
780 template <bool IsMaskT = OutputIsMask>
781 typename std::enable_if<IsMaskT, bool>::type
782 makeSphere(const Vec3R& p, Real r, const AttT& att, AccessorT& acc)
783 {
784 const Real
785 rSquared = r * r, // sphere radius squared, in voxel units
786 inW = r / math::Sqrt(6.0); // half the width in voxel units of an inscribed cube
787 const Coord
788 // Bounding box of the sphere
789 outLo(math::Floor(p[0] - r), math::Floor(p[1] - r), math::Floor(p[2] - r)),
790 outHi(math::Ceil(p[0] + r), math::Ceil(p[1] + r), math::Ceil(p[2] + r)),
791 // Bounds of the inscribed cube
792 inLo(math::Ceil(p[0] - inW), math::Ceil(p[1] - inW), math::Ceil(p[2] - inW)),
793 inHi(math::Floor(p[0] + inW), math::Floor(p[1] + inW), math::Floor(p[2] + inW));
794 // Bounding boxes of regions comprising out - in
795 /// @todo These could be divided further into sparsely- and densely-filled subregions.
796 const std::vector<CoordBBox> padding{
797 CoordBBox(outLo.x(), outLo.y(), outLo.z(), inLo.x()-1, outHi.y(), outHi.z()),
798 CoordBBox(inHi.x()+1, outLo.y(), outLo.z(), outHi.x(), outHi.y(), outHi.z()),
799 CoordBBox(outLo.x(), outLo.y(), outLo.z(), outHi.x(), inLo.y()-1, outHi.z()),
800 CoordBBox(outLo.x(), inHi.y()+1, outLo.z(), outHi.x(), outHi.y(), outHi.z()),
801 CoordBBox(outLo.x(), outLo.y(), outLo.z(), outHi.x(), outHi.y(), inLo.z()-1),
802 CoordBBox(outLo.x(), outLo.y(), inHi.z()+1, outHi.x(), outHi.y(), outHi.z()),
803 };
804 const ValueT onValue = Merge(SdfT(1), att);
805
806 // Sparsely fill the inscribed cube.
807 /// @todo Use sparse fill only if 2r > leaf width?
808 acc.tree().sparseFill(CoordBBox(inLo, inHi), onValue);
809
810 // Densely fill the remaining regions.
811 for (const auto& bbox: padding) {
812 if (util::wasInterrupted(mParent.mInterrupter)) {
813 thread::cancelGroupExecution();
814 return false;
815 }
816 const Coord &bmin = bbox.min(), &bmax = bbox.max();
817 Coord c;
818 Real cx, cy, cz;
819 for (c = bmin, cx = c.x(); c.x() <= bmax.x(); ++c.x(), cx += 1) {
820 const Real x2 = math::Pow2(cx - p[0]);
821 for (c.y() = bmin.y(), cy = c.y(); c.y() <= bmax.y(); ++c.y(), cy += 1) {
822 const Real x2y2 = x2 + math::Pow2(cy - p[1]);
823 for (c.z() = bmin.z(), cz = c.z(); c.z() <= bmax.z(); ++c.z(), cz += 1) {
824 const Real x2y2z2 = x2y2 + math::Pow2(cz - p[2]);
825 if (x2y2z2 < rSquared) {
826 acc.setValue(c, onValue);
827 }
828 }
829 }
830 }
831 }
832 return true;
833 }
834
835 using FuncType = typename std::function<void (Raster*, const tbb::blocked_range<size_t>&)>;
836
837 template<typename DisableType>
838 typename std::enable_if<DisableType::value>::type
839 getAtt(size_t, AttT&) const {}
840
841 template<typename DisableType>
842 typename std::enable_if<!DisableType::value>::type
843 getAtt(size_t n, AttT& a) const { mParticles.getAtt(n, a); }
844
845 template<typename T>
846 typename std::enable_if<std::is_same<T, ValueT>::value, ValueT>::type
847 Merge(T s, const AttT&) const { return s; }
848
849 template<typename T>
850 typename std::enable_if<!std::is_same<T, ValueT>::value, ValueT>::type
851 Merge(T s, const AttT& a) const { return ValueT(s,a); }
852
853 ParticlesToLevelSetT& mParent;
854 const ParticleListT& mParticles;//list of particles
855 GridT* mGrid;
856 const math::MapBase& mMap;
857 size_t mMinCount, mMaxCount;//counters for ignored particles!
858 FuncType mTask;
859 const bool mIsCopy;
860 PointPartitionerT* mPointPartitioner;
861 }; // struct ParticlesToLevelSet::Raster
862
863
864 ///////////////////// YOU CAN SAFELY IGNORE THIS SECTION /////////////////////
865
866 /// @cond OPENVDB_DOCS_INTERNAL
867
868 namespace p2ls_internal {
869
870 // This is a simple type that combines a distance value and a particle
871 // attribute. It's required for attribute transfer which is defined in the
872 // Raster class above.
873 /// @private
874 template<typename VisibleT, typename BlindT>
875 class BlindData
876 {
877 public:
878 using type = VisibleT;
879 using VisibleType = VisibleT;
880 using BlindType = BlindT;
881
882 BlindData() {}
883 explicit BlindData(VisibleT v) : mVisible(v), mBlind(zeroVal<BlindType>()) {}
884 BlindData(VisibleT v, BlindT b) : mVisible(v), mBlind(b) {}
885 BlindData(const BlindData&) = default;
886 BlindData& operator=(const BlindData&) = default;
887 const VisibleT& visible() const { return mVisible; }
888 const BlindT& blind() const { return mBlind; }
889 OPENVDB_NO_FP_EQUALITY_WARNING_BEGIN
890 bool operator==(const BlindData& rhs) const { return mVisible == rhs.mVisible; }
891 OPENVDB_NO_FP_EQUALITY_WARNING_END
892 bool operator< (const BlindData& rhs) const { return mVisible < rhs.mVisible; }
893 bool operator> (const BlindData& rhs) const { return mVisible > rhs.mVisible; }
894 BlindData operator+(const BlindData& rhs) const { return BlindData(mVisible + rhs.mVisible); }
895 BlindData operator-(const BlindData& rhs) const { return BlindData(mVisible - rhs.mVisible); }
896 BlindData operator-() const { return BlindData(-mVisible, mBlind); }
897
898 protected:
899 VisibleT mVisible;
900 BlindT mBlind;
901 };
902
903 /// @private
904 // Required by several of the tree nodes
905 template<typename VisibleT, typename BlindT>
906 inline std::ostream& operator<<(std::ostream& ostr, const BlindData<VisibleT, BlindT>& rhs)
907 {
908 ostr << rhs.visible();
909 return ostr;
910 }
911
912 /// @private
913 // Required by math::Abs
914 template<typename VisibleT, typename BlindT>
915 inline BlindData<VisibleT, BlindT> Abs(const BlindData<VisibleT, BlindT>& x)
916 {
917 return BlindData<VisibleT, BlindT>(math::Abs(x.visible()), x.blind());
918 }
919
920 /// @private
921 // Required to support the (zeroVal<BlindData>() + val) idiom.
922 template<typename VisibleT, typename BlindT, typename T>
923 inline BlindData<VisibleT, BlindT>
924 operator+(const BlindData<VisibleT, BlindT>& x, const T& rhs)
925 {
926 return BlindData<VisibleT, BlindT>(x.visible() + static_cast<VisibleT>(rhs), x.blind());
927 }
928
929 } // namespace p2ls_internal
930
931 /// @endcond
932
933 //////////////////////////////////////////////////////////////////////////////
934
935
936 // The following are convenience functions for common use cases.
937
938 template<typename GridT, typename ParticleListT, typename InterrupterT>
939 inline void
940 particlesToSdf(const ParticleListT& plist, GridT& grid, InterrupterT* interrupt)
941 {
942 static_assert(std::is_floating_point<typename GridT::ValueType>::value,
943 "particlesToSdf requires an SDF grid with floating-point values");
944
945 if (grid.getGridClass() != GRID_LEVEL_SET) {
946 OPENVDB_LOG_WARN("particlesToSdf requires a level set grid;"
947 " try Grid::setGridClass(openvdb::GRID_LEVEL_SET)");
948 }
949
950 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
951 p2ls.rasterizeSpheres(plist);
952 tools::pruneLevelSet(grid.tree());
953 }
954
955 template<typename GridT, typename ParticleListT, typename InterrupterT>
956 inline void
957 particlesToSdf(const ParticleListT& plist, GridT& grid, Real radius, InterrupterT* interrupt)
958 {
959 static_assert(std::is_floating_point<typename GridT::ValueType>::value,
960 "particlesToSdf requires an SDF grid with floating-point values");
961
962 if (grid.getGridClass() != GRID_LEVEL_SET) {
963 OPENVDB_LOG_WARN("particlesToSdf requires a level set grid;"
964 " try Grid::setGridClass(openvdb::GRID_LEVEL_SET)");
965 }
966
967 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
968 p2ls.rasterizeSpheres(plist, radius);
969 tools::pruneLevelSet(grid.tree());
970 }
971
972 template<typename GridT, typename ParticleListT, typename InterrupterT>
973 inline void
974 particleTrailsToSdf(const ParticleListT& plist, GridT& grid, Real delta, InterrupterT* interrupt)
975 {
976 static_assert(std::is_floating_point<typename GridT::ValueType>::value,
977 "particleTrailsToSdf requires an SDF grid with floating-point values");
978
979 if (grid.getGridClass() != GRID_LEVEL_SET) {
980 OPENVDB_LOG_WARN("particlesToSdf requires a level set grid;"
981 " try Grid::setGridClass(openvdb::GRID_LEVEL_SET)");
982 }
983
984 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
985 p2ls.rasterizeTrails(plist, delta);
986 tools::pruneLevelSet(grid.tree());
987 }
988
989 template<typename GridT, typename ParticleListT, typename InterrupterT>
990 inline void
991 particlesToMask(const ParticleListT& plist, GridT& grid, InterrupterT* interrupt)
992 {
993 static_assert(std::is_same<bool, typename GridT::ValueType>::value,
994 "particlesToMask requires a boolean-valued grid");
995 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
996 p2ls.rasterizeSpheres(plist);
997 tools::prune(grid.tree());
998 }
999
1000 template<typename GridT, typename ParticleListT, typename InterrupterT>
1001 inline void
1002 particlesToMask(const ParticleListT& plist, GridT& grid, Real radius, InterrupterT* interrupt)
1003 {
1004 static_assert(std::is_same<bool, typename GridT::ValueType>::value,
1005 "particlesToMask requires a boolean-valued grid");
1006 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
1007 p2ls.rasterizeSpheres(plist, radius);
1008 tools::prune(grid.tree());
1009 }
1010
1011 template<typename GridT, typename ParticleListT, typename InterrupterT>
1012 inline void
1013 particleTrailsToMask(const ParticleListT& plist, GridT& grid, Real delta, InterrupterT* interrupt)
1014 {
1015 static_assert(std::is_same<bool, typename GridT::ValueType>::value,
1016 "particleTrailsToMask requires a boolean-valued grid");
1017 ParticlesToLevelSet<GridT> p2ls(grid, interrupt);
1018 p2ls.rasterizeTrails(plist, delta);
1019 tools::prune(grid.tree());
1020 }
1021
1022 } // namespace tools
1023 } // namespace OPENVDB_VERSION_NAME
1024 } // namespace openvdb
1025
1026 #endif // OPENVDB_TOOLS_PARTICLES_TO_LEVELSET_HAS_BEEN_INCLUDED
1027