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Added a much more robust IntersectionPlaneMeshQuality function to compute the intersection between a mesh and a plane that exploit quality for storing the distance from the plane and to make consistent decision about the cutting of the plane...

This commit is contained in:
Paolo Cignoni 2011-11-15 11:19:08 +00:00
parent e0055f8b5c
commit f9a7860f5e
1 changed files with 72 additions and 19 deletions
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89
vcg/complex/algorithms/intersection.h
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@ -93,6 +93,7 @@ bool IntersectionPlaneGrid( GridType & grid, Plane3<ScalarType> plane, std::vect
/*@}*/ /*@}*/
/** \addtogroup complex */ /** \addtogroup complex */
/*@{*/ /*@{*/
/** /**
@ -108,28 +109,80 @@ bool IntersectionPlaneMesh(TriMeshType & m,
Plane3<ScalarType> pl, Plane3<ScalarType> pl,
EdgeMeshType & em) EdgeMeshType & em)
{ {
typename EdgeMeshType::VertexIterator vi; typename EdgeMeshType::VertexIterator vi;
typename TriMeshType::FaceIterator fi; typename TriMeshType::FaceIterator fi;
em.Clear(); em.Clear();
Segment3<ScalarType> seg; Segment3<ScalarType> seg;
for(fi=m.face.begin();fi!=m.face.end();++fi) for(fi=m.face.begin();fi!=m.face.end();++fi)
if(!(*fi).IsD()) if(!(*fi).IsD())
{ {
if(vcg::IntersectionPlaneTriangle(pl,*fi,seg))// intersezione piano triangolo if(vcg::IntersectionPlaneTriangle(pl,*fi,seg))// intersezione piano triangolo
{ {
vcg::tri::Allocator<EdgeMeshType>::AddEdges(em,1); vcg::tri::Allocator<EdgeMeshType>::AddEdges(em,1);
vi = vcg::tri::Allocator<EdgeMeshType>::AddVertices(em,2); vi = vcg::tri::Allocator<EdgeMeshType>::AddVertices(em,2);
(*vi).P() = seg.P0(); (*vi).P() = seg.P0();
em.edge.back().V(0) = &(*vi); em.edge.back().V(0) = &(*vi);
vi++; vi++;
(*vi).P() = seg.P1(); (*vi).P() = seg.P1();
em.edge.back().V(1) = &(*vi); em.edge.back().V(1) = &(*vi);
} }
}//end for }//end for
return true; return true;
} }
/** \addtogroup complex */
/*@{*/
/**
Basic Function computing the intersection between a trimesh and a plane. It returns an EdgeMesh without needing anything else.
Note: This version always returns a segment for each triangle of the mesh which intersects with the plane. In other
words there are 2*n vertices where n is the number of segments fo the mesh. You can run vcg::edge:Unify to unify
the vertices closer that a given value epsilon. Note that, due to subtraction error during triangle plane intersection,
it is not safe to put epsilon to 0.
// TODO si dovrebbe considerare la topologia face-face della trimesh per derivare quella della edge mesh..
*/
template < typename TriMeshType, typename EdgeMeshType, class ScalarType >
bool IntersectionPlaneMeshQuality(TriMeshType & m,
Plane3<ScalarType> pl,
EdgeMeshType & em)
{
std::vector<Point3f> ptVec;
tri::UpdateQuality<TriMeshType>::VertexFromPlane(m,pl);
for(size_t i=0;i<m.face.size();i++)
if(!m.face[i].IsD())
{
ptVec.clear();
for(int j=0;j<3;++j)
{
if((m.face[i].V0(j)->Q() * m.face[i].V1(j)->Q())<0)
{
const Point3f &p0 = m.face[i].V0(j)->cP();
const Point3f &p1 = m.face[i].V1(j)->cP();
// printf("Intersection ( %3.2f %3.2f %3.2f )-( %3.2f %3.2f %3.2f )\n",p0[0],p0[1],p0[2],p1[0],p1[1],p1[2]);
Point3f pp;
Segment3f seg(p0,p1);
IntersectionPlaneSegment(pl,seg,pp);
ptVec.push_back(pp);
}
if(m.face[i].V(j)->Q()==0) ptVec.push_back(m.face[i].V(j)->cP());
}
if(ptVec.size()>=2)
{
typename EdgeMeshType::VertexIterator vi;
vcg::tri::Allocator<EdgeMeshType>::AddEdges(em,1);
vi = vcg::tri::Allocator<EdgeMeshType>::AddVertices(em,2);
(*vi).P() = ptVec[0];
em.edge.back().V(0) = &(*vi);
vi++;
(*vi).P() = ptVec[1];
em.edge.back().V(1) = &(*vi);
}
}
return true;
}
/** \addtogroup complex */ /** \addtogroup complex */
/*@{*/ /*@{*/
/** /**