[vtkusers] Test if point is in- or outside a surface-body

[Dominik Szczerba]

Hmmm and what will you do if you will have two circles one inside 
another (e.g. cutting a sphere inside a sphere)? You have to shoot rays 
again. And doing so in an arbitrary plane might pose severe numerical 
problems (coplanarity) - no? Or somehow derive polygon orientation from 
the surfaces - but that does not sound easy either.

Dominik

Bryn Lloyd wrote:
> Hi Dominik,
> 
> Axel recently explained to me, that it is more robust to cut the surface 
> with a plane (which passes through the point), and then test 
> "insidedness" in this plane, i.e. using a simpler but more robust 
> inside-polygon test. I have not tried but thought you might be interested.
> 
> Cheers
> Bryn
> 
> 
> 
> 
> 
> 
> Dominik Szczerba wrote:
>> Yes, obb tree, shooting a ray and counting intersections.
>> HOWEVER, it is not very robust in VTK.
>> Dominik
>>
>> Charles Monty Burns wrote:
>>> Hello,
>>>
>>> I want to prove whether a point is in- or outside a body. Is there a 
>>> class to do this in a suitable way?
>>>
>>> Gretting
>>>
>>>
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> 
> 

-- 
Dominik Szczerba, PhD
Computational Physics Group
IT'IS Foundation
http://www.itis.ethz.ch