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[tang <>]

Dear Dr. Loriot,

Thank you very very much for your so kindly reply. I will test the code you
provided soon. For the first rule of triangle area, I have the following
idea: check whether the distance of one vertex to the opposite edge is less
then EPS, if true, I will split the triangle into two (the new point is the
projection of the vertex to the opposite edge. However, I don't know how to
implement it in two key steps:
1) how to get the vertices of the facet (triangle)?
2) how to split one facet (triangle) into two and update it to the original
polyhedron?

Thanks,
Zhanghong Tang



PS: The following is my code:


void splitsmalltriangle(myobj *object,double edgelengthmin)
{
        /// this function is used to split small triangles height smaller 
than the
given threshold
        /// a point will be inserted into one edge and the triangle will be
splitted into two 
        /// Zhanghong Tang @ 10/02/2012
        Polyhedron *obj=(Polyhedron *)object->obj;
        /// check for small area triangle
        Point_3 p1, p2, p3, p;
        Line_3 l;
        double area, d12, d23, d31, dmax;
  for (  Facet_iterator i = obj->facets_begin(); i != obj->facets_end();
++i) 
        {
                /// how to get 3 points of this facet(triangle)?
                Triangle_3 t(p1,p2,p3);
                area=2.0*sqrt(CGAL::to_double(t.squared_area ())); 
                d12=sqrt(CGAL::to_double(CGAL::squared_distance(p1,p2)));
                if(d12<=edgelengthmin)continue;
                d23=sqrt(CGAL::to_double(CGAL::squared_distance(p2,p3)));
                if(d23<=edgelengthmin)continue;
                d31=sqrt(CGAL::to_double(CGAL::squared_distance(p3,p1)));
                if(d31<=edgelengthmin)continue;
                dmax=max(max(d12, d23), d31);
                if(dmax>edgelengthmin)continue;
                /// get the projection of pi to longest edge
                if(dmax==d12)
                {
                        l=Line_3(p1,p2);
                        p=l.projection(p3);
                }
                else if(dmax==d23)
                {
                        l=Line_3(p2,p3);
                        p=l.projection(p1);
                }
                else
                {
                        l=Line_3(p3,p1);
                        p=l.projection(p2);
                }
                /// how to split facet(triangle) (p1,p2,p3) to 2 
facets(triangles) and
update 
                /// it to '*obj'?
        }
}




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