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Further tuning of poisson disk sampling pruning. Now we check also if the Spatial Hash Index is not over filled,

This commit is contained in:
Paolo Cignoni 2013-09-10 13:41:16 +00:00
parent de2738a7c3
commit d974bf2770
1 changed files with 33 additions and 20 deletions
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53
vcg/complex/algorithms/point_sampling.h
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@ -1289,18 +1289,18 @@ static void ComputePoissonSampleRadii(MetroMesh &sampleMesh, ScalarType diskRadi
}
}
// Trivial approach that puts all the samples in a UG and removes all the ones that surely do not fit the
static void PoissonDiskPruning(VertexSampler &ps, MetroMesh &montecarloMesh,
ScalarType diskRadius, const struct PoissonDiskParam pp=PoissonDiskParam())
{
// spatial index of montecarlo samples - used to choose a new sample to insert
MontecarloSHT montecarloSHT;
// initialize spatial hash table for searching
// radius is the radius of empty disk centered over the samples (e.g. twice of the empty space disk)
// This radius implies that when we pick a sample in a cell all that cell will not be touched again.
ScalarType cellsize = 4.0f* diskRadius / sqrt(3.0);
int t0 = clock();
// initialize spatial hash table for searching
// radius is the radius of empty disk centered over the samples (e.g. twice of the empty space disk)
// This radius implies that when we pick a sample in a cell all that cell probably will not be touched again.
// Howvever we must ensure that we do not put too many vertices inside each hash
static void InitSpatialHashTable(MetroMesh &montecarloMesh, MontecarloSHT &montecarloSHT, ScalarType diskRadius,
const struct PoissonDiskParam pp=PoissonDiskParam())
{
ScalarType cellsize = 2.0f* diskRadius / sqrt(3.0);
float occupancyRatio=0;
do
{
// inflating
BoxType bb=montecarloMesh.bbox;
assert(!bb.IsNull());
@ -1312,24 +1312,37 @@ static void PoissonDiskPruning(VertexSampler &ps, MetroMesh &montecarloMesh,
Point3i gridsize(sizeX, sizeY, sizeZ);
if(pp.pds) pp.pds->gridSize = gridsize;
montecarloSHT.InitEmpty(bb, gridsize);
for (VertexIterator vi = montecarloMesh.vert.begin(); vi != montecarloMesh.vert.end(); vi++)
montecarloSHT.Add(&(*vi));
montecarloSHT.UpdateAllocatedCells();
pp.pds->gridCellNum = (int)montecarloSHT.AllocatedCells.size();
cellsize/=2.0f;
occupancyRatio = float(montecarloMesh.vn) / float(montecarloSHT.AllocatedCells.size());
qDebug(" %i / %i = %i", montecarloMesh.vn / montecarloSHT.AllocatedCells.size(),occupancyRatio);
}
while( occupancyRatio> 100);
}
// Trivial approach that puts all the samples in a UG and removes all the ones that surely do not fit the
static void PoissonDiskPruning(VertexSampler &ps, MetroMesh &montecarloMesh,
ScalarType diskRadius, const struct PoissonDiskParam pp=PoissonDiskParam())
{
int t0 = clock();
// spatial index of montecarlo samples - used to choose a new sample to insert
MontecarloSHT montecarloSHT;
InitSpatialHashTable(montecarloMesh,montecarloSHT,diskRadius,pp);
// if we are doing variable density sampling we have to prepare the random samples quality with the correct expected radii.
// At this point we just assume that there is the quality values as sampled from the base mesh
if(pp.adaptiveRadiusFlag)
ComputePoissonSampleRadii(montecarloMesh, diskRadius, pp.radiusVariance, pp.invertQuality);
montecarloSHT.InitEmpty(bb, gridsize);
for (VertexIterator vi = montecarloMesh.vert.begin(); vi != montecarloMesh.vert.end(); vi++)
montecarloSHT.Add(&(*vi));
montecarloSHT.UpdateAllocatedCells();
unsigned int (*p_myrandom)(unsigned int) = RandomInt;
std::random_shuffle(montecarloSHT.AllocatedCells.begin(),montecarloSHT.AllocatedCells.end(), p_myrandom);
int t1 = clock();
if(pp.pds) {
pp.pds->gridCellNum = (int)montecarloSHT.AllocatedCells.size();
pp.pds->montecarloSampleNum = montecarloMesh.vn;
}
int removedCnt=0;