diff --git a/vcg/space/intersection2.h b/vcg/space/intersection2.h
index 073f3ce2..c081c200 100644
--- a/vcg/space/intersection2.h
+++ b/vcg/space/intersection2.h
@@ -187,39 +187,38 @@ namespace vcg {
 		return ((d0<length)&&(d1<length));
 	}
 
-	/// interseciton between point and triangle
+	/// interseciton between two segments
 	template<class SCALAR_TYPE>
 	inline bool SegmentSegmentIntersection(const vcg::Segment2<SCALAR_TYPE> &seg0,
 		const vcg::Segment2<SCALAR_TYPE> &seg1,
 		Point2<SCALAR_TYPE> &p_inters)
 	{
-		vcg::Line2<SCALAR_TYPE> l0,l1;
+		const SCALAR_TYPE Eps= SCALAR_TYPE(1e-8);
+		SCALAR_TYPE lambda0,lambda1;
+        const Point2<SCALAR_TYPE> & p0 = seg0.P0();
+        const Point2<SCALAR_TYPE> & p1 = seg0.P1();
+        const Point2<SCALAR_TYPE> & p2 = seg1.P0();
+        const Point2<SCALAR_TYPE> & p3 = seg1.P1();
 
-		l0.SetOrigin(seg0.P0());
-		vcg::Point2<SCALAR_TYPE> dir0=seg0.P1()-seg0.P0();
-		dir0.Normalize();
-		l0.SetDirection(dir0);
+		SCALAR_TYPE a = (p1-p0)[0];
+		SCALAR_TYPE b = (p2-p3)[0];
+		SCALAR_TYPE c = (p1-p0)[1];
+		SCALAR_TYPE d = (p2-p3)[1];
 
-		l1.SetOrigin(seg1.P0());
-		vcg::Point2<SCALAR_TYPE> dir1=seg1.P1()-seg1.P0();
-		dir1.Normalize();
-		l1.SetDirection(dir1);
-		LineLineIntersection(l0,l1,p_inters);
-		SCALAR_TYPE len0=seg0.Length();
-		SCALAR_TYPE len1=seg1.Length();
-		SCALAR_TYPE d0=(seg0.P0()-p_inters).Norm();
-		SCALAR_TYPE d1=(seg1.P0()-p_inters).Norm();
+		SCALAR_TYPE e = (p2-p0)[0];
+        SCALAR_TYPE f = (p2-p0)[1];
 
-		if ((d0>len0)||(d1>len1))
+		SCALAR_TYPE det = a*d-b*c;
+
+		lambda0 = (d*e-b*f)/det;
+		lambda1 = (-c*e+a*f)/det;
+        if (fabs(det)<Eps)
+			return false;// they are parallell
+		
+		if (!(lambda0 >= 0.0 && lambda0 <= 1.0 && lambda1 >= 0.0 && lambda1 <= 1.0))
 			return false;
-
-		vcg::Point2<SCALAR_TYPE> dir2=p_inters-seg0.P0();
-		vcg::Point2<SCALAR_TYPE> dir3=p_inters-seg1.P0();
-		if (((dir2*dir0)<0)||((dir3*dir1)<0))
-			return false;
-
+        p_inters = p0*(1-lambda0)+p1*lambda0;
 		return true;
-
 	}
 	/// interseciton between point and triangle
 	template<class SCALAR_TYPE>