/*
* missing in CGAL?
*/
squared_distance_t squaredDistancePointTriangle3D(
const Point_3& p,
const Triangle_3& abc
)
{
#if CGAL_VERSION_NR >= 1041001000 // >= 4.10
return CGAL::squared_distance(p, abc);
#else
Point_3 a = abc.vertex( 0 );
Point_3 b = abc.vertex( 1 );
Point_3 c = abc.vertex( 2 );
/*
* project P on ABC plane as projP.
*/
Point_3 projP = Plane_3( a, b, c ).projection( p );
squared_distance_t dMin ;
if ( abc.has_on( projP ) ) {
// Is projP is in the triangle, return distance from P to its projection
// on the plane
dMin = CGAL::squared_distance( p, projP ) ;
}
else {
// Else, the distance is the minimum from P to triangle sides
dMin = CGAL::squared_distance( p, Segment_3( a,b ) ) ;
dMin = std::min( dMin, CGAL::squared_distance( p, Segment_3( b,c ) ) );
dMin = std::min( dMin, CGAL::squared_distance( p, Segment_3( c,a ) ) );
}
return dMin ;
#endif
}
float
sdf( const Point& q, const Mesh &mesh, const vector<double>& weights,
KdTree& kd_tree, const Triangulation& triang )
{
VECTOR3 query (CGAL::to_double(q.x()),
CGAL::to_double(q.y()),
CGAL::to_double(q.z()));
kd_tree.queryPosition(query);
// Initialize the search structure, and search all N points
int n_vid = kd_tree.getNeighbourPositionIndex(0);
if(n_vid == -1) throw std::runtime_error("No nearest neighbor. MDS empty?");
CGAL_assertion( ! mesh.vert_list[n_vid].iso());
MVertex nv = mesh.vert_list[n_vid];
double min_sq_d = HUGE;
int n_fid = -1;
for(int i = 0; i < nv.num_inc_face; i ++)
{
MFace f = mesh.face_list[nv.inc_face(i)];
Point p[3] = {mesh.vert_list[f.get_corner(0)].point(),
mesh.vert_list[f.get_corner(1)].point(),
mesh.vert_list[f.get_corner(2)].point()};
Triangle_3 t (p[0], p[1], p[2]);
Plane_3 H (p[0], p[1], p[2]);
Point _q = H.projection(q);
// check if _q is inside t.
if( t.has_on(_q) )
{
double sq_d = CGAL::to_double((q-_q)*(q-_q));
if( sq_d < min_sq_d ) { min_sq_d = sq_d; n_fid = nv.inc_face(i); }
}
else
{
for(int j = 0; j < 3; j ++)
{
double _d = CGAL::to_double(CGAL::squared_distance(_q,Segment(p[j], p[(j+1)%3])));
double sq_d = CGAL::to_double((q-_q)*(q-_q)) + _d;
if( sq_d < min_sq_d ) { min_sq_d = sq_d; n_fid = nv.inc_face(i); }
}
}
}
// locate the query point in the triang which is already tagged
// with in-out flag by the reconstruction.
bool is_q_outside = false;
Triangulation::Locate_type lt;
int u = -1, v = -1;
Cell_handle c = triang.locate(q, lt, u, v);
if( lt == Triangulation::OUTSIDE_AFFINE_HULL )
{
is_q_outside = true;
cerr << "Point " << q << " is outside the affine hull." << endl;
}
else if( lt == Triangulation::OUTSIDE_CONVEX_HULL )
is_q_outside = true;
else
{
if( lt == Triangulation::CELL )
{
if( c->outside )
is_q_outside = true;
else
is_q_outside = false;
}
else if( lt == Triangulation::FACET )
{
Cell_handle _c = c->neighbor(u);
if( c->outside && _c->outside )
is_q_outside = true;
else
is_q_outside = false;
}
else if( lt == Triangulation::EDGE )
{
if( is_outside_VF(triang, Edge(c, u, v)) )
is_q_outside = true;
else
is_q_outside = false;
}
else
{
CGAL_assertion( lt == Triangulation::VERTEX );
is_q_outside = false;
}
}
double w;
if(weights.size() && mesh.face_list[n_fid].label != -1) w = weights[mesh.face_list[n_fid].label];
else w = 1.0;
// double w = mesh.face_list[n_fid].w;
double gen_sdf = 0;
if( is_q_outside ) gen_sdf = w*sqrt(min_sq_d);
else gen_sdf = -w*min_sq_d;
#if 0
double MAX = 10, MIN = -10;
if( gen_sdf > MAX ) gen_sdf = MAX;
if( gen_sdf < MIN ) gen_sdf = MIN;
#endif
return gen_sdf;
}