RhinoCommon Mesh.Vertices.Combin

RhinoCommon 中对Mesh 进行顶点焊接，可以使用CombineIdentical方法，参考代码如下：

Mesh capFace = new Mesh();
if (!(M.IsClosed))
{
Polyline[] nakedBoundaries = M.GetNakedEdges();

for (int i = 0; i <= nakedBoundaries.Count() - 1; i++)
{
capFace = Mesh.CreateFromClosedPolyline(nakedBoundaries[i]);
M.Append(capFace);
}
M.Vertices.CombineIdentical(true, true);
M.Normals.ComputeNormals();
M.UnifyNormals();
}

A = M;

以下为错误动作示范:

private void RunScript(Mesh M, ref object A)
{

Mesh capFace = new Mesh();
Mesh capFaces = new Mesh();

if (!(M.IsClosed))
{
Polyline[] nakedBoundaries = M.GetNakedEdges();

for (int i = 0; i <= nakedBoundaries.Count() - 1; i++)
{
capFace = Mesh.CreateFromClosedPolyline(nakedBoundaries[i]);
capFaces.Append(capFace);
}

M.Append(capFaces);
M.Vertices.CombineIdentical(false, true);
//if I put first option (ignore normals)as true I get invalid mesh
//With false I get a valid mesh but its doesnt seem to actually combine the Vertices
//M.Weld(Math.PI); <----why does weld work?

M.UnifyNormals();
}

A = M;
}

It works correctly for adding one cap as such

private void RunScript(Mesh M, ref object A)
{

Mesh capFace = new Mesh(); Mesh capFaces = new Mesh();
if (!(M.IsClosed))
{
Polyline[] nakedBoundaries = M.GetNakedEdges();

for (int i = 0; i <= 0 ;i++) // once cap
{
capFace = Mesh.CreateFromClosedPolyline(nakedBoundaries[i]);
M.Append(capFace);
}

M.Vertices.CombineIdentical(true, true);
}

A = M;
}

https://www.grasshopper3d.com/forum/topics/c-mesh-vertices-combineidentical-after-mesh-append-results

对于Mesh操作，以下列出一些参考：

        mesh.HealNakedEdges(radius);
        mesh.Vertices.CombineIdentical(true, true);
        mesh.Vertices.CullUnused();
        mesh.Weld(3.14159265358979);
        mesh.FaceNormals.ComputeFaceNormals();
        mesh.Normals.ComputeNormals();

        if (mesh.SolidOrientation() == -1)
            mesh.Flip(true, true, true);

        mesh.Compact();

以下展示使用Rtree达到同样效果(速度偏慢)：

//Store naked mesh vertices and their ids
List<Point3f> pts = new List<Point3f>();
bool[] flag = M.GetNakedEdgePointStatus();

allPointsFound = new List<List<int>>();

//History is need to stop searching rtee
//When all point groups are found
history.Clear();

//Create Rtree
RTree tree = new RTree();

for(int i = 0; i < flag.Length; i++){
  if(flag[i]){
    tree.Insert(M.Vertices[i], i);
    pts.Add(M.Vertices[i]);
  }
}

//Search RTree
for(int i = 0; i < pts.Count; i++){
  tempIDList = new List<int>();
  tree.Search(new Sphere(pts[i], radius), method);

  if(tempIDList.Count > 1)
    allPointsFound.Add(tempIDList);

  if(history.Count == M.Vertices.Count)
    break;
}

//Now move found vertices to one of firs vertex position
foreach(List<int> i in allPointsFound)
  for(int j = 1; j < i.Count; j++)
    M.Vertices[i[0]] = M.Vertices[i[j]];

M.Vertices.CombineIdentical(false, false);


A = M;

}

// <Custom additional code> 

  //Rtree collections
  List<int> history = new List<int>();
  List<List<int>> allPointsFound;
  List<int> tempIDList;

  private void method(object sender, RTreeEventArgs e){
    if(!history.Contains(e.Id)){
     tempIDList.Add(e.Id);
      history.Add(e.Id);
    }
  }
···
[https://discourse.mcneel.com/t/welding-meshes/69131/4](https://discourse.mcneel.com/t/welding-meshes/69131/4)