[SciPy-User] 3d convex hull

Pauli Virtanen pav at iki.fi
Sat Aug 27 18:08:18 EDT 2011


Sat, 27 Aug 2011 23:12:24 +0800, Ning Guo wrote:
> On Saturday, August 27, 2011 03:53 PM, Pauli Virtanen wrote:
[clip]
> Also, the formula to calculate normal may be like this:
> 
> face_normals[:,0] =
> np.cross(tetra_points[:,0]-tetra_points[:,2],tetra_points[:,1]-tetra_points[:,2])
[clip]

Ah yes, exactly like that, my brain apparently wasn't working properly.

> Regarding to the order of the vertices, I'm also not sure about their
> convention. I'm trying to figure it out.

If you find it out, please let us know, as this would be an useful thing
to mention in the documentation. However, I'm not sure at the moment
whether Qhull provides such ordering guarantees.

-- 
Pauli Virtanen




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