[vtkusers] some help please with raycasting!

[Christos Panagiotou]

dear all

this is my second post about this subject :) - sorry for being redundant!

I have a problem with raycasting and i am not sure if it is 
implementable in vtk (i dont have the vtk book!)

I have a 3D volume and I want to select points on its surface. What I 
thought to do is to cast rays from the centre of mass of the volume for 
set angles in all directions and save they intersections as the points.

Do you know if I can do this in vtk? If i do, which vtk method should i 
use? (I ve tried to understand what they do from the online 
documentation however I did not find for example methods to set for 
example the ray source in a specific point (centroid of volume in my 
case) or how to set the direction of the rays!)

I would be very very greatful if you could reply to my message as I have 
a deadline to catch and I need to do something with the above matter!!

thank you very much for your time
all the best
christos