diff --git a/apps/sample/trimesh_align_pair/trimesh_align_pair.cpp b/apps/sample/trimesh_align_pair/trimesh_align_pair.cpp
index 3073797d..b7903151 100644
--- a/apps/sample/trimesh_align_pair/trimesh_align_pair.cpp
+++ b/apps/sample/trimesh_align_pair/trimesh_align_pair.cpp
@@ -23,9 +23,14 @@
 /*! \file trimesh_align_pair.cpp
 \ingroup code_sample
 
-\brief the minimal example of using the lib
+\brief the minimal example for aligning two meshes
 
-This file contain a minimal example of the library
+This file contain a minimal example for aligning two meshs.
+
+Example call:
+./trimesh_align_pair mesh1.ply mesh2.ply output.ply
+
+output.ply will contain mesh2.ply rotated in order to be aligned to mesh1.ply
 
 */
 
@@ -39,11 +44,22 @@ This file contain a minimal example of the library
 class MyFace;
 class MyVertex;
 
-struct MyUsedTypes : public vcg::UsedTypes<	vcg::Use<MyVertex>::AsVertexType,    vcg::Use<MyFace>::AsFaceType>{};
+struct MyUsedTypes :
+		public vcg::UsedTypes<	vcg::Use<MyVertex>::AsVertexType,
+		vcg::Use<MyFace>::AsFaceType>
+{};
 
-class MyVertex  : public vcg::Vertex< MyUsedTypes, vcg::vertex::Coord3d, vcg::vertex::Normal3d, vcg::vertex::Color4b, vcg::vertex::BitFlags  >{};
-class MyFace    : public vcg::Face < MyUsedTypes, vcg::face::VertexRef, vcg::face::Normal3d, vcg::face::FFAdj, vcg::face::Mark, vcg::face::BitFlags > {};
-class MyMesh    : public vcg::tri::TriMesh< std::vector<MyVertex>, std::vector<MyFace> > {};
+class MyVertex :
+		public vcg::Vertex< MyUsedTypes, vcg::vertex::Coord3d, vcg::vertex::Normal3d, vcg::vertex::Color4b, vcg::vertex::BitFlags>
+{};
+
+class MyFace :
+		public vcg::Face < MyUsedTypes, vcg::face::VertexRef, vcg::face::Normal3d, vcg::face::FFAdj, vcg::face::Mark, vcg::face::BitFlags >
+{};
+
+class MyMesh :
+		public vcg::tri::TriMesh< std::vector<MyVertex>, std::vector<MyFace> >
+{};
 
 using namespace vcg;
 using namespace std;
@@ -58,6 +74,10 @@ int main(int argc,char ** argv)
 		printf("Usage: trimesh_smooth <filename> <filename>\n");
 		return 0;
 	}
+	std::string outputname = "output.ply";
+	if (argc == 4){
+		outputname = std::string(argv[3]);
+	}
 
 	MyMesh m1, m2;
 
@@ -75,24 +95,17 @@ int main(int argc,char ** argv)
 		exit(-1);
 	}
 
+	//update normals
 	vcg::tri::UpdateNormal<MyMesh>::PerVertexNormalizedPerFace(m1);
 	vcg::tri::UpdateNormal<MyMesh>::PerVertexNormalizedPerFace(m2);
 
 	////PARAMS
-	/////TODO
 	vcg::AlignPair::Result result;
 	vcg::AlignPair::Param ap;
-
-	//MovM
-	//vcg::Matrix44d FixM=vcg::Matrix44d::Construct(m1.Tr);
-	//MovM=vcg::Matrix44d::Construct(m2.Tr);
-	//MovM = Inverse(FixM) * MovM;
-
 	vcg::AlignPair::A2Mesh fix;
 	vcg::AlignPair aa;
 
 	// 1) Convert fixed mesh and put it into the grid.
-	//m1.face.EnableMark();
 	aa.convertMesh<MyMesh>(m1,fix);
 
 	vcg::AlignPair::A2Grid UG;
@@ -109,8 +122,6 @@ int main(int argc,char ** argv)
 
 
 	// 2) Convert the second mesh and sample a <ap.SampleNum> points on it.
-	//MM(movId)->updateDataMask(MeshModel::MM_FACEMARK);
-	//m2.face.EnableMark();
 	std::vector<vcg::AlignPair::A2Vertex> tmpmv;
 	aa.convertVertex(m2.vert,tmpmv);
 	aa.sampleMovVert(tmpmv, ap.SampleNum, ap.SampleMode);
@@ -119,20 +130,19 @@ int main(int argc,char ** argv)
 	aa.fix=&fix;
 	aa.ap = ap;
 
+	//use identity as first matrix
 	vcg::Matrix44d In;
 	In.SetIdentity();
+
 	// Perform the ICP algorithm
 	aa.align(In,UG,VG,result);
 
+	//rotate m2 using the resulting transformation
 	tri::UpdatePosition<MyMesh>::Matrix(m2, result.Tr, true);
 	tri::UpdateBounding<MyMesh>::Box(m2);
 
-	//result.FixName=fixId;
-	//result.MovName=movId;
-	//result.as.Dump(stdout);
-
 	//saves the rotated mesh
-	tri::io::ExporterPLY<MyMesh>::Save(m2 ,"out.ply");
+	tri::io::ExporterPLY<MyMesh>::Save(m2 ,outputname.c_str());
 
 	return 0;
 }