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Refactoring of the Poisson Sampling algorithm. Hopefully faster

This commit is contained in:
Paolo Cignoni 2009-11-25 15:50:36 +00:00
parent 7e02dbb4f8
commit a209a9b890
1 changed files with 54 additions and 32 deletions
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86
vcg/complex/trimesh/point_sampling.h
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@ -827,6 +827,27 @@ static void ComputePoissonSampleRadii(MetroMesh &sampleMesh, ScalarType diskRadi
} }
} }
static void removeUselessSample(MontecarloSHT &montecarloSHT, VertexType *vp, ScalarType radius)
{
// get the samples closest to the given one
std::vector<VertexType*> closests;
typedef VertTmark<MetroMesh> MarkerVert;
MarkerVert mv;
Box3f bb(vp->cP()-Point3f(radius,radius,radius),vp->cP()+Point3f(radius,radius,radius));
int nsamples = GridGetInBox(montecarloSHT, mv, bb, closests);
ScalarType r2 = radius*radius;
for(int i=0; i<closests.size(); ++i)
{
if(SquaredDistance(vp->cP(),closests[i]->cP()) <= r2)
{
montecarloSHT.Remove(closests[i]);
}
}
}
/** Compute a Poisson-disk sampling of the surface. /** Compute a Poisson-disk sampling of the surface.
* The radius of the disk is computed according to the estimated sampling density. * The radius of the disk is computed according to the estimated sampling density.
* *
@ -864,6 +885,8 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
SampleSHT checkSHT; SampleSHT checkSHT;
// initialize spatial hash table for searching // 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 = diskRadius / sqrt(3.0); ScalarType cellsize = diskRadius / sqrt(3.0);
// inflating // inflating
@ -875,6 +898,7 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
Point3i gridsize(sizeX, sizeY, sizeZ); Point3i gridsize(sizeX, sizeY, sizeZ);
#ifdef QT_VERSION #ifdef QT_VERSION
qDebug("PDS: radius %f Grid:(%i %i %i) ",diskRadius,sizeX,sizeY,sizeZ); qDebug("PDS: radius %f Grid:(%i %i %i) ",diskRadius,sizeX,sizeY,sizeZ);
int t0=clock();
#endif #endif
// initialize spatial hash to index pre-generated samples // initialize spatial hash to index pre-generated samples
VertexIterator vi; VertexIterator vi;
@ -885,7 +909,8 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
verticescounter[0]++; verticescounter[0]++;
} }
#ifdef QT_VERSION #ifdef QT_VERSION
qDebug("PDS: Completed montercarloSHT, inserted %i vertex in %i cells", montecarloMesh.vn, montecarloSHT.AllocatedCells.size()); int t1=clock();
qDebug("PDS: Completed montercarloSHT, inserted %i vertex in %i cells (%i)", montecarloMesh.vn, montecarloSHT.AllocatedCells.size(), t1-t0);
#endif #endif
// initialize spatial hash table for check poisson-disk radius constrain // initialize spatial hash table for check poisson-disk radius constrain
checkSHT.InitEmpty(origMesh.bbox, gridsize); checkSHT.InitEmpty(origMesh.bbox, gridsize);
@ -906,7 +931,7 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
typename std::vector<VertexType *>::iterator nextPointsIt; typename std::vector<VertexType *>::iterator nextPointsIt;
typename std::vector<Point3i>::iterator it; typename std::vector<Point3i>::iterator it;
Point3i *currentCell;
vcg::Box3<ScalarType> currentBox; vcg::Box3<ScalarType> currentBox;
int level = 0; int level = 0;
@ -930,19 +955,13 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
int ncell = static_cast<int>(activeCells.size()); int ncell = static_cast<int>(activeCells.size());
cellusedcounter[level] = ncell; cellusedcounter[level] = ncell;
// shuffle active cells // shuffle active cells
// int index,index2;
// Point3i *temp;
// for (int i = 0; i < ncell/2; i++)
// {
// index = RandomInt(ncell);
// index2 = RandomInt(ncell);
// temp = activeCells[index];
// activeCells[index] = activeCells[index2];
// activeCells[index2] = temp;
// }
unsigned int (*p_myrandom)(unsigned int) = RandomInt; unsigned int (*p_myrandom)(unsigned int) = RandomInt;
std::random_shuffle(activeCells.begin(),activeCells.end(), p_myrandom); std::random_shuffle(activeCells.begin(),activeCells.end(), p_myrandom);
#ifdef QT_VERSION
int t2=clock();
qDebug("PDS: Completed creation of activeCells, %i cells (%i)", montecarloSHT.AllocatedCells.size(), t2-t1);
#endif
// generate a sample inside C by choosing one of the contained pre-generated samples // generate a sample inside C by choosing one of the contained pre-generated samples
@ -950,8 +969,9 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
for (int i = 0; i < ncell; i++) for (int i = 0; i < ncell; i++)
{ {
currentCell = activeCells[i]; Point3i *currentCell = activeCells[i];
//vcg::Point3<ScalarType > s; // current sample //vcg::Point3<ScalarType > s; // current sample
if(montecarloSHT.CellSize(*currentCell) == 0 ) continue;
// generate a sample chosen from the pre-generated one // generate a sample chosen from the pre-generated one
VertexPointer sp = getPrecomputedMontecarloSample(currentCell, montecarloSHT); VertexPointer sp = getPrecomputedMontecarloSample(currentCell, montecarloSHT);
@ -961,8 +981,8 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
ScalarType sampleRadius = diskRadius; ScalarType sampleRadius = diskRadius;
if(pp.adaptiveRadiusFlag) sampleRadius = sp->Q(); if(pp.adaptiveRadiusFlag) sampleRadius = sp->Q();
if (checkPoissonDisk(*ps.m, checkSHT, sp->cP(), sampleRadius)) //if (checkPoissonDisk(*ps.m, checkSHT, sp->cP(), sampleRadius))
{ {
// add sample // add sample
tri::Allocator<MetroMesh>::AddVertices(supportMesh,1); tri::Allocator<MetroMesh>::AddVertices(supportMesh,1);
supportMesh.vert.back().P() = sp->P(); supportMesh.vert.back().P() = sp->P();
@ -970,26 +990,28 @@ static void Poissondisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
//ps.AddVert(supportMesh.vert.back()); Small change, we should call the sampler class with the input mesh. //ps.AddVert(supportMesh.vert.back()); Small change, we should call the sampler class with the input mesh.
ps.AddVert(*sp); ps.AddVert(*sp);
removeUselessSample(montecarloSHT,sp,sampleRadius);
// add to control spatial index // add to control spatial index
checkSHT.Add(&supportMesh.vert.back()); checkSHT.Add(&supportMesh.vert.back());
samplesaccepted[level]++; samplesaccepted[level]++;
} }
else // else
{ // {
// subdivide this cell // // subdivide this cell
/////////////////////////////////////////////////////////////////////// // ///////////////////////////////////////////////////////////////////////
// pre-generated samples for the next level of subdivision // // pre-generated samples for the next level of subdivision
MontecarloSHTIterator ptBegin, ptEnd, ptIt; // MontecarloSHTIterator ptBegin, ptEnd, ptIt;
montecarloSHT.Grid(*currentCell, ptBegin, ptEnd); // montecarloSHT.Grid(*currentCell, ptBegin, ptEnd);
//
for (ptIt = ptBegin; ptIt != ptEnd; ++ptIt) // for (ptIt = ptBegin; ptIt != ptEnd; ++ptIt)
{ // {
nextPoints.push_back(*ptIt); // nextPoints.push_back(*ptIt);
} // }
//
cellstosubdividecounter[level]++; // cellstosubdividecounter[level]++;
} // }
} }
activeCells.clear(); activeCells.clear();
@ -1140,4 +1162,4 @@ static void SubdivideAndSample(MetroMesh & m, std::vector<Point3f> &pvec, const
} // end namespace vcg } // end namespace vcg
#endif #endif