[vtkusers] creating a solid object from 3D points

[Tim Hutton]

Hi Clare,

First of all, are your points completely random or are they captured
in some direction, such as left-to-right? If so then you will probably
have more success using this fact to derive a surface. If your points
are geographical, for example, then a projection into 2D followed by
vtkDelaunay2D is the best option.

If the points are definitely in a random order then you need some form
of surface reconstruction. VTK has vtkSurfaceReconstructionFilter but
it only works if your data is densely sampled all over, and the
surface is closed.

A better algorithm is found in the following, which is written for VTK
but covered by the GPL:
http://www.sq3.org.uk/powercrust/

Tim

On 9/11/06, Clare Fitzpatrick <clare.fitzpatrick at ucd.ie> wrote:
>
>
> Hi,
>
> I have a set of x,y,z points which i want to convert to a solid object.
> I am reading them into vtk using vtkParticleReader:
>
> vtkParticleReader reader
>   reader SetFileName "C:/points3D.txt"
>   reader SetDataByteOrderToBigEndian
>
> vtkPolyDataMapper mapper
>     mapper SetInputConnection [reader GetOutputPort]
>
> vtkActor actor
>     actor SetMapper mapper
>     [actor GetProperty] SetPointSize 1
>
> ren1 AddActor actor
>
>
> The points in my .txt file are in a random order. Is it possible to create a
> solid object (the shape you'd get if you shrink-wrapped something around all
> the points) directly from these points, or do i have to arrange them into a
> particlar order so that i can use vtkDelaunay2D or vtkCellArray and
> vtkPolyData to create the surface?
>
> Thanks
>
> Clare
>
>
> _______________________________________________
> This is the private VTK discussion list.
> Please keep messages on-topic. Check the FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
>
>
>


-- 
Tim Hutton - http://www.sq3.org.uk

Take the Organic Builder challenge -
http://www.sq3.org.uk/Evolution/Squirm3/OrganicBuilder/