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Subject: How to find (and plot) surface normal
Date: Tue, 6 Apr 2010 20:33:24 +0000 (UTC)
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Hey,

I have a 3D point cloud.
I need to create a surface mesh and find the normal vector to each vertex. 

I wrote a very naive method that:
-- finds the normal vector of each triangle in the mesh
-- finds the neighboring trinagles of each vertex
-- returns the sum of all the neighbors' noramls as the vertex normal  

My questions are:
1. Is this correct? Is there a better way to find the surface normal?
2. How can I plot the result so I can see the whole mesh with its normals?
    I use "trisurf" to plot the mesh, but I don't know how to add the normal vectors..
(sorry if this is trivial, I'm quite new with matlab..)

Thanks,
Li