vcglib/vcg/complex/intersection.h

120 lines
3.9 KiB
C++

#include<vector>
#include<vcg/space/point3.h>
#include<vcg/space/plane3.h>
#include<vcg/space/segment3.h>
#include<vcg/space/intersection3.h>
#include<vcg/space/index/grid_static_ptr.h>
namespace vcg{
/** \addtogroup complex */
/*@{*/
/**
Function computing the intersection between a grid and a plane. It returns all the cells intersected
*/
template < typename GridType,typename ScalarType>
bool Intersect( GridType & grid,Plane3<ScalarType> plane, vector<typename GridType::Cell *> &cells){
Point3d p,_d;
Plane3d pl;
_d.Import(plane.Direction());
pl.SetDirection(_d);
pl.SetOffset(plane.Offset());
for( int ax = 0; ax <3; ++ax)
{ int axis = ax;
int axis0 = (axis+1)%3;
int axis1 = (axis+2)%3;
int i,j;
Point3i pi;
Segment3<double> seg;
seg.P0().Import(grid.bbox.min);
seg.P1().Import(grid.bbox.min);
seg.P1()[axis] = grid.bbox.max[axis];
for(i = 0 ; i <= grid.siz[axis0]; ++i){
for(j = 0 ; j <= grid.siz[axis1]; ++j)
{
seg.P0()[axis0] = grid.bbox.min[axis0]+ (i+0.01) * grid.voxel[axis0] ;
seg.P1()[axis0] = grid.bbox.min[axis0]+ (i+0.01) * grid.voxel[axis0];
seg.P0()[axis1] = grid.bbox.min[axis1]+ (j+0.01) * grid.voxel[axis1];
seg.P1()[axis1] = grid.bbox.min[axis1]+ (j+0.01) * grid.voxel[axis1];
if ( Intersection(pl,seg,p))
{
pi[axis] = min(max(0,floor((p[axis ]-grid.bbox.min[axis])/grid.voxel[axis])),grid.siz[axis]);
pi[axis0] = i;
pi[axis1] = j;
grid.Grid(pi,axis,cells);
}
}
}
}
sort(cells.begin(),cells.end());
cells.erase(unique(cells.begin(),cells.end()),cells.end());
return false;
}
/*@}*/
/** \addtogroup complex */
/*@{*/
/**
Function computing the intersection between a trimesh and a plane. It returns an EdgeMesh.
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 Intersection( TriMeshType & m, Plane3<ScalarType> pl,EdgeMeshType & em,double& ave_length,
typename GridStaticPtr<typename TriMeshType::FaceContainer> *grid,
typename vector< typename GridStaticPtr<typename TriMeshType::FaceContainer>::Cell* >& cells){
typedef typename TriMeshType::FaceContainer FaceContainer;
typedef GridStaticPtr<FaceContainer> GridType;
EdgeMeshType::VertexIterator vi;
TriMeshType::FaceIterator fi;
vector<TriMeshType::FaceType*> v;
v.clear();
Intersect(*grid,pl,cells);
Segment3<ScalarType> seg;
ave_length = 0.0;
vector<GridType::Cell*>::iterator ic;
GridType::Cell fs,ls;
for(ic = cells.begin(); ic != cells.end();++ic)
{
grid->Grid(*ic,fs,ls);
GridType::Link * lk = fs;
while(lk != ls){
TriMeshType::FaceType & face = *(lk->Elem());
if(!face.IsS())
{
face.SetS();
v.push_back(&face);
if(vcg::Intersection(pl,face,seg))// intersezione piano triangolo
{
face.SetS();
// add to em
ave_length+=seg.Length();
vcg::edge::Allocator<EdgeMeshType>::AddEdges(em,1);
vi = vcg::edge::Allocator<EdgeMeshType>::AddVertices(em,2);
(*vi).P() = seg.P0();
em.edges.back().V(0) = &(*vi);
vi++;
(*vi).P() = seg.P1();
em.edges.back().V(1) = &(*vi);
}
}//endif
lk++;
}//end while
}
ave_length/=em.en;
vector<TriMeshType::FaceType*>::iterator v_i;
for(v_i=v.begin(); v_i!=v.end(); ++v_i) (*v_i)->ClearS();
return true;
}
/*@}*/
} // end namespace vcg