[vtkusers] closest point on a surface / vtkIterativeClosestPointTransform

[Steffen Oeltze]

Yes, it works. Instead of creating the surface, I import a surface.
Then, I'm using vtkMaskPoints as well to randomly select surface
vertices. Next, I apply some noise to these vertices, a little bit of
translation and rotation. Finally, I use the ICP to bring the points
back to the surface.

Then, I measured the Euclidean distance between the transformed points
(before and after ICP) and the surface. For that purpose, I use:


vtkCellLocator *locator = vtkCellLocator::New();
	locator->SetDataSet(data); // data represents the surface
	locator->SetNumberOfCellsPerBucket(1);
	locator->BuildLocator();
	locator->Update();

in a loop:

locator->FindClosestPoint(inPoint, closestPointOnSurface, cell_id,
sub_id, dist2);

Cheers,
Steffen




Jason Taclas schrieb:
> have you gotten this to work?  I'm having trouble on a similar project; 
> I am also using vtkIterativeClosestPoint to register a point cloud to a 
> surface, and I also need to make distance measurements.  If it matters 
> at all, my surface was created with vtkMarchingCubes.  I used 
> vtkMaskPoints with GenerateVerticesOn to get to vertices, is this what 
> you did?
> 
> On Feb 15, 2008 9:21 AM, Steffen Oeltze 
> <stoeltze at isg.cs.uni-magdeburg.de 
> <mailto:stoeltze at isg.cs.uni-magdeburg.de>> wrote:
> 
>     Thanks a lot for the hint! I'm using vtkCellLocator now to determine the
>     closest point on a surface for a given position in 3D.
> 
>     Steffen
> 
>     cedric.schwartz at enst-bretagne.fr
>     <mailto:cedric.schwartz at enst-bretagne.fr> schrieb:
>      > Hi,
>      > As far as I know you can't have the distance information with the ICP
>      > transform. Maybe you should try vtkPointLocator or vtkKdTree in
>     order to
>      > obtain the distance measure.
>      > Cedric
>      >
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