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refactored laplacian smoothing and added taubin smoothing

This commit is contained in:
Paolo Cignoni 2008-07-04 00:32:48 +00:00
parent 3af17fab9a
commit a8becdc8f1
1 changed files with 145 additions and 59 deletions
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144
vcg/complex/trimesh/smooth.h
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@ -260,6 +260,8 @@ static void VertexCoordScaleDependentLaplacian_Fujiwara(MeshType &m, int step, S
class LaplacianInfo
{
public:
LaplacianInfo(const CoordType &_p, const int _n):sum(_p),cnt(_n) {}
LaplacianInfo() {}
CoordType sum;
ScalarType cnt;
};
@ -267,23 +269,19 @@ public:
// Classical Laplacian Smoothing. Each vertex can be moved onto the average of the adjacent vertices.
// Can smooth only the selected vertices and weight the smoothing according to the quality
// In the latter case 0 means that the vertex is not moved and 1 means that the vertex is moved onto the computed position.
static void VertexCoordLaplacian(MeshType &m, int step, bool SmoothSelected=false, float QualityWeight=0)
//
// From the Taubin definition "A signal proc approach to fair surface design"
// We define the discrete Laplacian of a discrete surface signal by weighted averages over the neighborhoods
// \delta xi = \Sum wij (xj - xi) ;
// where xj are the adjacent vertices of xi and wij is usually 1/n_adj
//
// This function simply accumulate over a TempData all the positions of the ajacent vertices
//
static void AccumulateLaplacianInfo(MeshType &m, SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > &TD)
{
LaplacianInfo lpz;
lpz.sum=CoordType(0,0,0);
lpz.cnt=1;
SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > TD(m.vert,lpz);
for(int i=0;i<step;++i)
{
VertexIterator vi;
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
{
TD[*vi].cnt=1;
TD[*vi].sum=(*vi).P();
}
FaceIterator fi;
for(fi=m.face.begin();fi!=m.face.end();++fi)
{
if(!(*fi).IsD())
for(int j=0;j<3;++j)
if(!(*fi).IsB(j))
@ -293,23 +291,24 @@ static void VertexCoordLaplacian(MeshType &m, int step, bool SmoothSelected=fals
++TD[(*fi).V(j)].cnt;
++TD[(*fi).V1(j)].cnt;
}
}
// si azzaera i dati per i vertici di bordo
for(fi=m.face.begin();fi!=m.face.end();++fi)
{
if(!(*fi).IsD())
for(int j=0;j<3;++j)
if((*fi).IsB(j))
{
//TD[(*fi).V(j)]=lpz;
//TD[(*fi).V1(j)]=lpz;
TD[(*fi).V0(j)].sum=(*fi).P0(j);
TD[(*fi).V1(j)].sum=(*fi).P1(j);
TD[(*fi).V0(j)].cnt=1;
TD[(*fi).V1(j)].cnt=1;
}
}
// se l'edge j e' di bordo si deve mediare solo con gli adiacenti
for(fi=m.face.begin();fi!=m.face.end();++fi)
{
if(!(*fi).IsD())
for(int j=0;j<3;++j)
if((*fi).IsB(j))
@ -319,26 +318,113 @@ static void VertexCoordLaplacian(MeshType &m, int step, bool SmoothSelected=fals
++TD[(*fi).V(j)].cnt;
++TD[(*fi).V1(j)].cnt;
}
}
}
if(QualityWeight>0)
{ // quality weighted smoothing
// We assume that weights are in the 0..1 range.
assert(tri::HasPerVertexQuality(m));
static void VertexCoordLaplacian(MeshType &m, int step, bool SmoothSelected=false)
{
VertexIterator vi;
LaplacianInfo lpz(CoordType(0,0,0),0);
SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > TD(m.vert,lpz);
for(int i=0;i<step;++i)
{
TD.Init(lpz);
AccumulateLaplacianInfo(m,TD);
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
{
if(!SmoothSelected || (*vi).IsS())
(*vi).P() = ( (*vi).P() + TD[*vi].sum)/(TD[*vi].cnt+1);
}
}
}
static void VertexCoordLaplacianBlend(MeshType &m, int step, float alpha, bool SmoothSelected=false)
{
VertexIterator vi;
LaplacianInfo lpz(CoordType(0,0,0),0);
assert (alpha<= 1.0);
SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > TD(m.vert);
for(int i=0;i<step;++i)
{
TD.Init(lpz);
AccumulateLaplacianInfo(m,TD);
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
{
if(!SmoothSelected || (*vi).IsS())
{
CoordType Delta = TD[*vi].sum/TD[*vi].cnt - (*vi).P();
(*vi).P() = (*vi).P() + Delta*alpha;
}
}
}
}
/* a couple of notes about the lambda mu values
We assume that 0 < lambda , and mu is a negative scale factor such that mu < - lambda.
Holds mu+lambda < 0 (e.g in absolute value mu is greater)
let kpb be the pass-band frequency, taubin says that:
kpb = 1/lambda + 1/mu >0
Values of kpb from 0.01 to 0.1 produce good results according to the original paper.
kpb * mu - mu/lambda = 1
mu = 1/(kpb-1/lambda )
So if lambda == 0.5 -> mu = 1/(0.1 - 2) = -0.53
*/
static void VertexCoordTaubin(MeshType &m, int step, float lambda, float mu, bool SmoothSelected=false)
{
LaplacianInfo lpz(CoordType(0,0,0),0);
SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > TD(m.vert,lpz);
VertexIterator vi;
for(int i=0;i<step;++i)
{
TD.Init(lpz);
AccumulateLaplacianInfo(m,TD);
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
{
if(!SmoothSelected || (*vi).IsS())
{
CoordType Delta = TD[*vi].sum/TD[*vi].cnt - (*vi).P();
(*vi).P() = (*vi).P() + Delta*lambda ;
}
}
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
{
if(!SmoothSelected || (*vi).IsS())
{
CoordType Delta = TD[*vi].sum/TD[*vi].cnt - (*vi).P();
(*vi).P() = (*vi).P() - Delta*mu ;
}
}
} // end for step
}
static void VertexCoordLaplacianQuality(MeshType &m, int step, bool SmoothSelected=false)
{
LaplacianInfo lpz;
lpz.sum=CoordType(0,0,0);
lpz.cnt=1;
SimpleTempData<typename MeshType::VertContainer,LaplacianInfo > TD(m.vert,lpz);
for(int i=0;i<step;++i)
{
for(VertexIterator vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
if(!SmoothSelected || (*vi).IsS())
{
float q=(*vi).Q();
(*vi).P()=(*vi).P()*q + (TD[*vi].sum/TD[*vi].cnt)*(1.0-q);
}
}
else
{
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD() && TD[*vi].cnt>0 )
if(!SmoothSelected || (*vi).IsS())
(*vi).P()=TD[*vi].sum/TD[*vi].cnt;
}
} // end for
};