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added multisampling distance field evaluation

This commit is contained in:
Paolo Cignoni 2009-01-15 01:31:09 +00:00
parent f001af1c5c
commit 0e037cabc1
1 changed files with 40 additions and 19 deletions
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59
vcg/complex/trimesh/create/resampler.h
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@ -92,6 +92,7 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
float max_dim; // the limit value of the search (that takes into account of the offset)
float offset; // an offset value that is always added to the returned value. Useful for extrarting isosurface at a different threshold
bool DiscretizeFlag; // if the extracted surface should be discretized or not.
bool MultiSampleFlag;
Walker(const Box3f &_bbox, Point3i _siz )
{
this->bbox= _bbox;
@ -102,6 +103,7 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
CurrentSlice = 0;
offset=0;
DiscretizeFlag=false;
MultiSampleFlag=false;
_x_cs = new VertexIndex[ SliceSize ];
_y_cs = new VertexIndex[ SliceSize ];
@ -144,13 +146,13 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
return VV(x,y,z).second+offset;
}
///return true if the distance form the mesh is less than maxdim and return distance
bool DistanceFromMesh(int x,int y,int z,Old_Mesh *mesh, float &dist)
field_value DistanceFromMesh(Point3f &pp,Old_Mesh *mesh)
{
float dist;
typename Old_Mesh::FaceType *f=NULL;
const float max_dist = max_dim;
vcg::Point3f testPt;
this->IPiToPf(Point3i(x,y,z),testPt);
this->IPfToPf(pp,testPt);
vcg::Point3f closestNormV,closestNormF;
vcg::Point3f closestPt;
@ -162,7 +164,7 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
DISTFUNCTOR PDistFunct;
f = _g.GetClosest(PDistFunct,markerFunctor,testPt,max_dist,dist,closestPt);
if (f==NULL) return false;
if (f==NULL) return field_value(false,0);
assert(!f->IsD());
bool retIP;
@ -183,7 +185,7 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
float signV = dir.dot(closestNormV) ;
float signF = dir.dot(closestNormF) ;
// Note that the two sings could be discordant.
// Note that the two signs could be discordant.
// Always choose the best one according to the magnitude.
float signBest;
if(fabs(signV) > fabs(signF)) signBest = signV;
@ -191,34 +193,54 @@ template <class OLD_MESH_TYPE,class NEW_MESH_TYPE, class FLT, class DISTFUNCTOR
if(signBest<0) dist=-dist;
return true;
return field_value(true,dist);
}
field_value MultiDistanceFromMesh(Point3f &pp,Old_Mesh *mesh)
{
float distSum=0;
int posCnt=0; // positive results counter
const int MultiSample=7;
const Point3f delta[7]={Point3f(0,0,0),
Point3f( 0.2, -0.01, -0.02),
Point3f(-0.2, 0.01, 0.02),
Point3f( 0.01, 0.2, 0.01),
Point3f( 0.03, -0.2, -0.03),
Point3f(-0.02, -0.03, 0.2 ),
Point3f(-0.01, 0.01, -0.2 )};
for(int qq=0;qq<MultiSample;++qq)
{
Point3f pp2=pp+delta[qq];
field_value ff= DistanceFromMesh(pp2,_oldM);
if(ff.first==false) return field_value(false,0);
distSum += fabs(ff.second);
if(ff.second>0) posCnt ++;
}
if(posCnt<=MultiSample/2) distSum = -distSum;
return field_value(true, distSum/MultiSample);
}
/// compute the values if an entire slice (per y) distances>dig of a cell are signed with double of
/// the distance of the bb
void ComputeSliceValues(int slice,field_value *slice_values)
{
float dist;
for (int i=0; i<=this->siz.X(); i++)
{
for (int k=0; k<=this->siz.Z(); k++)
{
int index=GetSliceIndex(i,k);
if (DistanceFromMesh(i,slice,k,_oldM,dist))///compute the distance,inside volume of the mesh is negative
{
//put computed values in the slice values matrix
slice_values[index]=field_value(true,dist);
//end putting values
}
else
slice_values[index]=field_value(false,0);
Point3f pp(i,slice,k);
if(this->MultiSampleFlag) slice_values[index] = MultiDistanceFromMesh(pp,_oldM);
else slice_values[index] = DistanceFromMesh(pp,_oldM);
}
}
//ComputeConsensus(slice,slice_values);
}
/*
For some reasons it can happens that the sign of the computed distance is not correct.
For some reasons it can happens that the sign of the computed distance could not correct.
this function tries to correct these issues by flipping the isolated voxels with discordant sign
*/
void ComputeConsensus(int slice, field_value *slice_values)
{
@ -574,18 +596,17 @@ typedef Walker /*< Old_Mesh,New_Mesh>*/ MyWalker;
typedef vcg::tri::MarchingCubes<New_Mesh, MyWalker> MyMarchingCubes;
///resample the mesh using marching cube algorithm ,the accuracy is the dimension of one cell the parameter
static void Resample(Old_Mesh &old_mesh,New_Mesh &new_mesh,vcg::Point3<int> accuracy,float max_dist, float thr=0, bool DiscretizeFlag=false, vcg::CallBackPos *cb=0 )
static void Resample(Old_Mesh &old_mesh,New_Mesh &new_mesh, Box3f volumeBox, vcg::Point3<int> accuracy,float max_dist, float thr=0, bool DiscretizeFlag=false, bool MultiSampleFlag=false, vcg::CallBackPos *cb=0 )
{
///be sure that the bounding box is updated
vcg::tri::UpdateBounding<Old_Mesh>::Box(old_mesh);
Box3f volumeBox = old_mesh.bbox;
volumeBox.Offset(volumeBox.Diag()/10.0f);
MyWalker walker(volumeBox,accuracy);
walker.max_dim=max_dist+fabs(thr);
walker.offset = - thr;
walker.DiscretizeFlag = DiscretizeFlag;
walker.MultiSampleFlag = MultiSampleFlag;
MyMarchingCubes mc(new_mesh, walker);
walker.BuildMesh(old_mesh,new_mesh,mc,cb);
}