Want to create a new mesh (single triangle) "cloned" from an already existing triangle ....

Hi,

I have a sort of a planet earth object, a mesh when i click on a it, i register the triangle i clicked on (i got to get its triangle index) from there i want to "create" a new mesh that is based on that very same triangle but would be like "hovering" over the original mesh (to achieve like a "floating" white clone of that triangle , this would show that the tile was selected, as it will turn into a white material)

(originally i planned to do it thru shader - but it's too hard for me now and i thought doing it with a mesh would make me learn about them - i thought about a Decal , but they are not in standard Unity yet, ....)

I have been struggling but i learned a lot about vertices and all, which is good, still i am at a stuck :

the new object is created and all, but it is empty and at the center of the world instead of being hovering the original triangle

here is the code of the function that does it all :

 // WHEN WHE click on a triangle on the "Earth Mesh", a new one is created, like a clone of that triange, just a bit hovering it, and as a separate object
     void SelectedTile(int triangleindex)
     {
 
         //check if a "Selected Tile" was already created (previous click) if yes, destroy it
         GameObject[] olderTiles;
         olderTiles = GameObject.FindGameObjectsWithTag("stile");
         if (olderTiles.Length != 0)
         {
             Debug.Log("OLDER TILE FOUND, must destroy it0");
             Destroy(olderTiles[0]);
 
         }
 
 
         Debug.Log("TILE SELECTED");
         Debug.Log("Triangle id : " + triangleindex);
 
         //get the whole mesh we clicked on, single out the vertices and the normals and the triangles
         Mesh mesh = transform.GetComponent<MeshFilter>().mesh;
         Vector3[] vertices = mesh.vertices;
         Vector3[] normals = mesh.normals;
         int[] triangles = mesh.triangles;
 
         //Single out the 3 vertices from a specific triangle (the one that has the index passed as a parameter triangleindex in the method)
         Vector3 p0 = vertices[triangles[triangleindex * 3 + 0]];
         Vector3 p1 = vertices[triangles[triangleindex * 3 + 1]];
         Vector3 p2 = vertices[triangles[triangleindex * 3 + 2]];
 
         //
         Transform hitTransform = transform;
         p0 = hitTransform.TransformPoint(p0);
         p1 = hitTransform.TransformPoint(p1);
         p2 = hitTransform.TransformPoint(p2);
 
         // Draw the triangle debug lines
         Color color = new Color(1f, 0f, 0f);
         Debug.DrawLine(p0, p1, color);
         Debug.DrawLine(p1, p2, color);
         Debug.DrawLine(p2, p0, color);
 
 
         // CREATE a new MESH to create a flat triangle
         // Set up game object with mesh;
         GameObject Selectedtile = new GameObject("Selectedtile_"+triangleindex);
         Selectedtile.tag = "stile";
 
         // add the right needed components
         Mesh newmesh = new Mesh();
         Selectedtile.AddComponent<MeshFilter>();
         Selectedtile.AddComponent<MeshRenderer>().material.color = Color.white;
         Selectedtile.GetComponent<MeshFilter>().mesh = newmesh;
         
         //create temp arrays for vertices and UVS and triangle
         Vector3[] newVertices = new Vector3[3]; //just need 3 i guess....
         Vector2[] newUV = new Vector2[3]; // same thing?
         int[] newTriangles = new int[3]; //i guess one would even be enough... ??
         
         //tell these vertices to be like the ones we got from the original target triangle but with little displacement so it "hovers" over it
         for (int i = 0; i < 3; i++)
         {
             newVertices[i] += vertices[triangles[triangleindex * 3 + 0]] + new Vector3(0.5f,0.5f,0.5f); //not sure about that....
         }
         
         //same thing for UVs....not sure about what i am doing.....
         for (int i = 0; i < 3; i++)
         {
             newUV[i] = new Vector2(vertices[i].x, vertices[i].z);
         }
 
         // assign the temp calculated arrays into the arrays of the new Mesh.
         newmesh.vertices = newVertices;
         newmesh.uv = newUV;
         newmesh.triangles = newTriangles;
         newmesh.RecalculateNormals();
         newmesh.RecalculateBounds();
 
 
     }