[vtkusers] Distance between PolyData and a point along a direction

[David Doria]

On Thu, Mar 29, 2012 at 4:17 AM, emreturkoz <emreturkoz at gmail.com> wrote:
> I have a point, and a point normal defined to it. Suppose I also have a
> polydata, which doesn't include or span this point.
>
> I want to find the distance from this point to the polydata along the
> polydata normal. By distance, I mean how far should I translate the point so
> that it "touches" the surface defined by polydata.
>
> Is this possible to do with vtk??

Is your polydata a mesh? If so, then you can use this:

http://www.vtk.org/Wiki/VTK/Examples/Cxx/DataStructures/ModifiedBSPTree_IntersectWithLine

You have to build the tree. Then you have to defined a second point
along your line (it is an intersection with a line segment, not an
actual infinite ray). Then you can do the intersection and get the
distance between the query point and the intersection.

David