[vtkusers] normals on points without polygons

[Cory Quammen]

Kiv,

There isn't a filter in VTK that will compute normals on a set of
points that I am aware of. However, a possible way to estimate the
normals is to create a regular grid of density values from the point
positions. You might estimate the density as the number of points that
fall within a voxel of the grid, or you might choose another way, such
as splatting Gaussians (see, vtkGaussianSplatter) into a grid. You can
then calculate the gradient of the density on the grid and use the
interpolated gradient at each point in your original data set as the
normal.

Hope that helps,
Cory

On Thu, Mar 6, 2008 at 11:33 AM, kývýlcým helhel <kvlcm_helhel at yahoo.com> wrote:
> Hi everyone,
>
> I had some data that include only  x,y,z information of points.I need to
> find the normal of each point.I try to use vtkPolyDataNormals but it finds
> normals with polygons so it did not useful for me.Is there any class or any
> way to fid point normals??
>
> Thanks...
> Kiv
>
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-- 
Cory Quammen
Department of Computer Science
University of North Carolina at Chapel Hill
http://www.cs.unc.edu/~cquammen