diff --git a/src/point_tris_dist.cc b/src/point_tris_dist.cc
index 0e7f921..3d82305 100644
--- a/src/point_tris_dist.cc
+++ b/src/point_tris_dist.cc
@@ -14,8 +14,7 @@ double pointSegmentDistance(double *p, double *a, double *b, double* direction)
         direction[0] = ap[0];
         direction[1] = ap[1];
         direction[2] = ap[2];
-        vtkMath::Normalize(direction);
-        return vtkMath::Norm(ap, 3);
+        return vtkMath::Normalize(direction);
     }
 
     double h = vtkMath::ClampValue(vtkMath::Dot(ap, ab) / segSqrLength, 0., 1.);
@@ -26,8 +25,7 @@ double pointSegmentDistance(double *p, double *a, double *b, double* direction)
     direction[0] = v[0];
     direction[1] = v[1];
     direction[2] = v[2];
-    vtkMath::Normalize(direction);
-	return vtkMath::Norm(v);
+    return vtkMath::Normalize(direction);
 }
 
 double pointTriangleDistance(double *p, vtkCell *triangle, double *direction) {
@@ -53,33 +51,20 @@ double pointTriangleDistance(double *p, vtkCell *triangle, double *direction) {
 	double dc = vtkMath::Dot(vecTC, cp);
 
 	if(da <= 0 && db <= 0 && dc <= 0) {
-        double na[3] = {
-            n[0] * a[0],
-            n[1] * a[1],
-            n[2] * a[2],
-        };
-
-        double np[3] = {
-            n[0] * p[0],
-            n[1] * p[1],
-            n[2] * p[2],
-        };
-
-        double t[3]; vtkMath::Subtract(np, na, t);
-
-        double nt[3] = {
-            n[0] * t[0],
-            n[1] * t[1],
-            n[2] * t[2],
-        };
-
-
-        direction[0] = nt[0];
-        direction[1] = nt[1];
-        direction[2] = nt[2];
-        vtkMath::Normalize(direction);
-        return vtkMath::Norm(nt);
+        double d = vtkMath::Dot(n, ap);
+        double n2 = vtkMath::Dot(n, n);
 
+        if(d >= 0) {
+            direction[0] = n[0];
+            direction[1] = n[1];
+            direction[2] = n[2];
+        } else {
+            direction[0] = -n[0];
+            direction[1] = -n[1];
+            direction[2] = -n[2];
+        }
+        
+        return sqrt(d * d / n2);
 	} else {
         double normalA[3];
         double normalB[3];