[vtkusers] Detect points inside or outside a space

[Alex Southern]

Hi,

I've been avoiding using VTK to do this, but it seems that it may be 
relatively simple to do rather coding it from scratch.

Basically, Id like to draw a volume in something like Google Sketchup 
use one of the free converters to generate a VTK file. Id then like to 
read that file into my own app (no problems here), and then define a 
cuboid container, around the volume of interest, which contains a 3D 
equally spaced grid of points (e.g 10 million), I then want to be able 
to interrogate each point to find out if it is inside or outside the volume.

The millions of points do not need to be visualized from an interaction 
point of view. So I suspect the points should be defined using 
vtkPoints? But how do I interrogate these to find out if they are inside 
or outside the volume.

The user could supply co-ordinates of a point that is definitely inside 
the volume, if necessary.

I have put up a temporary link to a typical volume of interest as a vtk 
file (Complex3D.vtk), this was drawn in sketchup.

http://www.tml.tkk.fi/~aps/ <http://www.tml.tkk.fi/%7Eaps/>

Any examples or nudges in the right direction would be greatly appreciated.

Thanks
Alex