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

[Dominik Szczerba]

Probably cutting in Cartesian planes would simplify a lot. But still I 
think simple inside_polygon test is not enough.

Dominik

Dominik Szczerba wrote:
> 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