Added a second function to compute the distance between a point and a box, according to the fact that you need the distance between the surface of a box or the distance from the filled box (e.g. the distance is 0 inside the box)

vcg/space/distance3.h

@@ -30,11 +30,37 @@
 
 namespace vcg {
 
+
+/*
+* Computes the minimum distance between a 3D box and a point
+* @param[in] p				The input point
+* @param[in] b				The input bounding box
+* return			The distance
+* This function returns 0 for points Inside the bbox while the next one return the distance from the surface
+*/
+template<class Scalar>
+Scalar PointFilledBoxDistance(const Point3<Scalar> &p, const Box3<Scalar> &bbox)
+{
+	Scalar dist2 = 0.;
+	Scalar aux;
+	for (int k=0 ; k<3 ; ++k)
+	{
+		if ( (aux = (p[k]-bbox.min[k]))<0. )
+			dist2 += aux*aux;
+		else if ( (aux = (bbox.max[k]-p[k]))<0. )
+			dist2 += aux*aux;
+	}
+	return sqrt(dist2);
+}
+
 /*
 * Computes the minimum distance between a 3D box and a point
 * @param[in] p				The input point
 * @param[in] b				The input bounding box
 * @param[out] dist			The distance
+* Note that this function with respect to the previous one compute the distance between a point
+* and the 'surface' of a Box3. 
+* 
 */
 template <class ScalarType> 
 void PointBoxDistance(const Point3<ScalarType> &p,
@@ -49,6 +75,7 @@ void PointBoxDistance(const Point3<ScalarType> &p,
 		const ScalarType dz = std::min<ScalarType>(b.max.Z()-p.Z(), p.Z()-b.min.Z());
 
 		dist= std::min<ScalarType>(dx, std::min<ScalarType>(dy, dz));
+		return;
 	}
     
 	{
@@ -81,7 +108,7 @@ void SpherePointDistance(const Sphere3<ScalarType> &sphere,
 }
 
 /*
-* Computes the minimum distance between a 3D box and a point
+* Computes the minimum distance between two spheres
 * @param[in] sphere0				The input sphere
 * @param[in] sphere1				The input sphere
 * @param[out] dist			The distance