CGAL users discussion list

[Nikolas Engelhard <>]

Hello

I'm writing a little raycasting-Program and have a problem with intersection a Triangle with a Ray. 

Since this intersection is not yet supported, I intersect the ray with the supporting plane of the Triangle

and check if the point is within the triangle. 

Here are my Definitions:

#include <CGAL/Exact_predicates_exact_constructions_kernel.h>

typedef  CGAL::Exact_predicates_exact_constructions_kernel K;

typedef  CGAL::Point_3<K> P;

typedef  CGAL::Triangle_3<K>  Tri;

typedef  CGAL::Ray_3<K> R;

typedef  CGAL::Vector_3<K> V;

and a little sample:

P t(0,0,0);

P q(10,0,0);

P r(0,10,0);

Tri tri(t,q,r);

P s(1,1,1);

V v(0,0,-1);

R ray(s,v);

P is(5,4.5,0);

cout << is << "      " << tri <<  endl;

if (tri.has_on(is)){

cout << "intersection" << endl;

}

else

cout <<"no intersection" << endl;

I would expect to find an intersection ( "is" lies on tri) but I get 

"Program received signal:  “EXC_BAD_ACCESS”."

after calling has_on. Other functions like intersection(ray,plane) work well und in some cases also this call works 

(with different values), so I have no idea, what to do. 

Does anyone has an idea?

Nikolas