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[tang <>]

Dear all,

I am trying to split surface triangles by inserting new nodes at some
locations, the function is as follows. However, it displayed 
Error!!!!!!!!!!!!!!!!!!!!!!!!

when boolean operation with another polyhedron after this function (it is OK
if this function does not work), could anyone take a look at it and give me
suggestion to modify the function?

Thanks,
Zhanghong Tang


The function:
void SplitTriangleAtZ(Polyhedron *obj,double r,double z)
{
        /// this function is used to split all triangles whose edges are at r 
and
included z
        /// i.e. a point with point.z =z will be inserted into the edges
        /// Zhanghong Tang @ 06/23/2013
        double eps=1.0e-10;
        /// check for small area triangle
        Point_3 p1, p2, p3, p;
        Halfedge_handle h, hnew, h1, h2, h3, ho, splitedge;

        double x1, y1, z1, x2, y2, z2, x3, y3, z3, xp, yp;
        double rr1,rr2,rr3,r2;
        int found;
        r2=r*r;
        while(1)
        {
                found=0;
                for ( Facet_iterator i = obj->facets_begin() ; i != 
obj->facets_end();
++i) 
                {
                        /// get 3 points of this facet(triangle)
                        h1 = i->halfedge();
                        h2 = h1->next();
                        h3 = h2->next();
                        /// (p3->p1): h1
                        /// (p1->p2): h->next()
                        /// (p2->p3): h->next()->next()
                        p1 = h1->vertex()->point();
                        p2 = h2->vertex()->point();
                        p3 = h3->vertex()->point();
                        x1=CGAL::to_double(p1.x());
                        x2=CGAL::to_double(p2.x());
                        x3=CGAL::to_double(p3.x());
                        y1=CGAL::to_double(p1.y());
                        y2=CGAL::to_double(p2.y());
                        y3=CGAL::to_double(p3.y());
                        z1=CGAL::to_double(p1.z());
                        z2=CGAL::to_double(p2.z());
                        z3=CGAL::to_double(p3.z());
                        if((z1-z)*(z2-z)<0.0)
                        {
                                rr1=x1*x1+y1*y1;
                                rr2=x2*x2+y2*y2;
                                if(rr1-r2<eps &amp;&amp; rr2-r2&lt;eps)  // 
p1, p2
                                {
                                        xp=x1+(z-z1)*(x2-x1)/(z2-z1);
                                        yp=y1+(z-z1)*(y2-y1)/(z2-z1);
                                        p=Point_3(xp,yp,z);
                                        splitedge = h2;  /// h2 will be 
splitted by p
                                        h = h3;
                                        found=1;
                                }
                        }
                        else if((z2-z)*(z3-z)&lt;0.0)
                        {
                                rr2=x2*x2+y2*y2;
                                rr3=x3*x3+y3*y3;
                                if(rr2-r2&lt;eps &amp;&amp; rr3-r2&lt;eps)  
// p2, p3
                                {
                                        xp=x2+(z-z2)*(x3-x2)/(z3-z2);
                                        yp=y2+(z-z2)*(y3-y2)/(z3-z2);
                                        p=Point_3(xp,yp,z);
                                        splitedge = h3;  /// h3 will be 
splitted by p
                                        h = h1;
                                        found=1;
                                }
                        }
                        else if((z3-z)*(z1-z)&lt;0.0)
                        {
                                rr3=x3*x3+y3*y3;
                                rr1=x1*x1+y1*y1;
                                if(rr3-r2&lt;eps &amp;&amp; rr1-r2&lt;eps)  
// p3, p1
                                {
                                        xp=x3+(z-z3)*(x1-x3)/(z1-z3);
                                        yp=y3+(z-z3)*(y1-y3)/(z1-z3);
                                        p=Point_3(xp,yp,z);
                                        splitedge = h1;  /// h1 will be 
splitted by p
                                        h = h2;
                                        found=1;
                                }
                        }
                        if(found==1)
                        {
                                /// the opposite facet
                                ho = splitedge->opposite()->next();
                                /// split the edge
                                hnew = obj->split_edge(splitedge);
                                /// set the new vertex
                                hnew->vertex()->point() = p;
                                /// split the facet
                                hnew = obj->split_facet(h, hnew);
                                /// split opposite facet
                                obj->split_facet(ho, splitedge->opposite());
                                break;
                        }
                }
                if(found==0)break;
        }
}




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