title: How to merge Two data sets of point clouds or polygons into one? (Merging not Appending)
body: <p>I am developing a real-time scanner, in which I would be able to scan the surface in real-time. Untill now I can scan one patch of the surface and can save it.
  One patch means just 1 scan of the surface (point cloud or triangles).</p>
  
  <p>What I want is, I want to scan multiple patches in real-time. For this purpose, I have to merge the previous patch with the current patch. But I don't know what is the standard way or algorithm to merge two patches and also I don't know which one is the best way for merging, for example, before triangulation (point cloud merging), or after the triangulation (mesh merging).
  Merging means remove overlapped points or triangles</p>
  
  <p>My idea: If there are two point clouds, source and target then using VTK, find a closest point from the target point cloud, and select one point the other is discarded. Is this a method for merging ? This is just my idea?
  But the problem is, the number of points in source and target will be different.</p>
  
  <p>How can I merge two patches using VTK, kindly guide me?</p>
  
  <p>Also suggest me what is the standard and optimum way to achieve real-time scanning task.</p>
  
  <p><strong>Case # 1:</strong><br>
  i) Point Cloud Aquisition</p>
  
  <p>ii) Register</p>
  
  <p>iii) Merge</p>
  
  <p>iv) Triangulate</p>
  
  <p><strong>Case # 2:</strong></p>
  
  <p>i) Point Cloud Aquisition</p>
  
  <p>ii) Register</p>
  
  <p>iii) Triangulate</p>
  
  <p>iv) Merge</p>
  
  <p><strong>Case # 3:</strong></p>
  
  <p>i) Point Cloud Aquisition</p>
  
  <p>ii) Triangulate</p>
  
  <p>iii)Register</p>
  
  <p>iv) Merge</p>
  
  <p>Please guide me.
  Thanks. </p>